Bump serde-wasm-bindgen from 0.3.1 to 0.6.5 (#6188 )

Bumps [serde-wasm-bindgen](https://github.com/RReverser/serde-wasm-bindgen) from 0.3.1 to 0.6.5. - [Commits](https://github.com/RReverser/serde-wasm-bindgen/commits/v0.6.5) --- updated-dependencies: - dependency-name: serde-wasm-bindgen dependency-version: 0.6.5 dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Handle OsError in REPL (#6187 )
2026-06-02 19:39:49 +09:00 · 2025-10-13 11:03:49 +09:00 · 2025-10-13 10:18:51 +09:00 · 2025-10-12 12:55:46 +09:00 · 2025-10-12 12:55:23 +09:00 · 2025-10-05 11:14:33 +09:00
1451 changed files with 218954 additions and 71105 deletions
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -3,3 +3,6 @@ rustflags = "-C link-arg=/STACK:8000000"

 [target.'cfg(all(target_os = "windows", not(target_env = "msvc")))']
 rustflags = "-C link-args=-Wl,--stack,8000000"
+
+[target.wasm32-unknown-unknown]
+rustflags = ["--cfg=getrandom_backend=\"wasm_js\""]
--- a/.coderabbit.yml
+++ b/.coderabbit.yml
@@ -0,0 +1,3 @@
+reviews:
+  path_filters:
+    - "!Lib/**"
--- a/.cspell.dict/cpython.txt
+++ b/.cspell.dict/cpython.txt
@@ -0,0 +1,62 @@
+argtypes
+asdl
+asname
+augassign
+badsyntax
+basetype
+boolop
+bxor
+cached_tsver
+cellarg
+cellvar
+cellvars
+cmpop
+denom
+dictoffset
+elts
+excepthandler
+fileutils
+finalbody
+formatfloat
+freevar
+freevars
+fromlist
+heaptype
+HIGHRES
+Itertool
+IMMUTABLETYPE
+kwonlyarg
+kwonlyargs
+lasti
+linearise
+maxdepth
+mult
+nkwargs
+noraise
+numer
+orelse
+pathconfig
+patma
+posonlyarg
+posonlyargs
+prec
+preinitialized
+PYTHREAD_NAME
+SA_ONSTACK
+stackdepth
+stringlib
+structseq
+subparams
+tok_oldval
+tvars
+unaryop
+unparse
+unparser
+VARKEYWORDS
+varkwarg
+wbits
+weakreflist
+withitem
+withs
+xstat
+XXPRIME
--- a/.cspell.dict/python-more.txt
+++ b/.cspell.dict/python-more.txt
@@ -0,0 +1,265 @@
+abiflags
+abstractmethods
+aenter
+aexit
+aiter
+anext
+appendleft
+argcount
+arrayiterator
+arraytype
+asend
+asyncgen
+athrow
+backslashreplace
+baserepl
+basicsize
+bdfl
+bigcharset
+bignum
+bivariant
+breakpointhook
+cformat
+chunksize
+classcell
+closefd
+closesocket
+codepoint
+codepoints
+codesize
+contextvar
+cpython
+cratio
+dealloc
+debugbuild
+decompressor
+defaultaction
+descr
+dictcomp
+dictitems
+dictkeys
+dictview
+digestmod
+dllhandle
+docstring
+docstrings
+dunder
+endianness
+endpos
+eventmask
+excepthook
+exceptiongroup
+exitfuncs
+extendleft
+fastlocals
+fdel
+fedcba
+fget
+fileencoding
+fillchar
+fillvalue
+finallyhandler
+firstiter
+firstlineno
+fnctl
+frombytes
+fromhex
+fromunicode
+fset
+fspath
+fstring
+fstrings
+ftruncate
+genexpr
+getattro
+getcodesize
+getdefaultencoding
+getfilesystemencodeerrors
+getfilesystemencoding
+getformat
+getframe
+getframemodulename
+getnewargs
+getpip
+getrandom
+getrecursionlimit
+getrefcount
+getsizeof
+getswitchinterval
+getweakrefcount
+getweakrefs
+getwindowsversion
+gmtoff
+groupdict
+groupindex
+hamt
+hostnames
+idfunc
+idiv
+idxs
+impls
+indexgroup
+infj
+instancecheck
+instanceof
+irepeat
+isabstractmethod
+isbytes
+iscased
+isfinal
+istext
+itemiterator
+itemsize
+iternext
+keepends
+keyfunc
+keyiterator
+kwarg
+kwargs
+kwdefaults
+kwonlyargcount
+lastgroup
+lastindex
+linearization
+linearize
+listcomp
+longrange
+lvalue
+mappingproxy
+maskpri
+maxdigits
+MAXGROUPS
+MAXREPEAT
+maxsplit
+maxunicode
+memoryview
+memoryviewiterator
+metaclass
+metaclasses
+metatype
+mformat
+mro
+mros
+multiarch
+namereplace
+nanj
+nbytes
+ncallbacks
+ndigits
+ndim
+nldecoder
+nlocals
+NOARGS
+nonbytes
+Nonprintable
+origname
+ospath
+pendingcr
+phello
+platlibdir
+popleft
+posixsubprocess
+posonly
+posonlyargcount
+prepending
+profilefunc
+pycache
+pycodecs
+pycs
+pyexpat
+PYTHONBREAKPOINT
+PYTHONDEBUG
+PYTHONDONTWRITEBYTECODE
+PYTHONHASHSEED
+PYTHONHOME
+PYTHONINSPECT
+PYTHONINTMAXSTRDIGITS
+PYTHONNOUSERSITE
+PYTHONOPTIMIZE
+PYTHONPATH
+PYTHONPATH
+PYTHONSAFEPATH
+PYTHONUNBUFFERED
+PYTHONVERBOSE
+PYTHONWARNDEFAULTENCODING
+PYTHONWARNINGS
+pytraverse
+PYVENV
+qualname
+quotetabs
+radd
+rdiv
+rdivmod
+readall
+readbuffer
+reconstructor
+refcnt
+releaselevel
+reverseitemiterator
+reverseiterator
+reversekeyiterator
+reversevalueiterator
+rfloordiv
+rlshift
+rmod
+rpow
+rrshift
+rsub
+rtruediv
+rvalue
+scproxy
+seennl
+setattro
+setcomp
+setrecursionlimit
+setswitchinterval
+showwarnmsg
+signum
+slotnames
+STACKLESS
+stacklevel
+stacksize
+startpos
+subclassable
+subclasscheck
+subclasshook
+suboffset
+suboffsets
+SUBPATTERN
+sumprod
+surrogateescape
+surrogatepass
+sysconf
+sysconfigdata
+sysvars
+teedata
+thisclass
+titlecased
+tkapp
+tobytes
+tolist
+toreadonly
+TPFLAGS
+tracefunc
+unimportable
+unionable
+unraisablehook
+unsliceable
+urandom
+valueiterator
+vararg
+varargs
+varnames
+warningregistry
+warnmsg
+warnoptions
+warnopts
+weaklist
+weakproxy
+weakrefs
+winver
+withdata
+xmlcharrefreplace
+xoptions
+xopts
+yieldfrom
--- a/.cspell.dict/rust-more.txt
+++ b/.cspell.dict/rust-more.txt
@@ -0,0 +1,86 @@
+ahash
+arrayvec
+bidi
+biguint
+bindgen
+bitand
+bitflags
+bitor
+bitxor
+bstr
+byteorder
+byteset
+caseless
+chrono
+consts
+cranelift
+cstring
+datelike
+deserializer
+deserializers
+fdiv
+flamescope
+flate2
+fract
+getres
+hasher
+hexf
+hexversion
+idents
+illumos
+indexmap
+insta
+keccak
+lalrpop
+lexopt
+libc
+libcall
+libloading
+libz
+longlong
+Manually
+maplit
+memmap
+memmem
+metas
+modpow
+msvc
+muldiv
+nanos
+nonoverlapping
+objclass
+peekable
+powc
+powf
+powi
+prepended
+punct
+replacen
+rmatch
+rposition
+rsplitn
+rustc
+rustfmt
+rustyline
+seedable
+seekfrom
+siphash
+siphasher
+splitn
+subsec
+thiserror
+timelike
+timsort
+trai
+ulonglong
+unic
+unistd
+unraw
+unsync
+wasip1
+wasip2
+wasmbind
+wasmtime
+widestring
+winapi
+winsock
--- a/.cspell.json
+++ b/.cspell.json
@@ -1,207 +1,85 @@
 // See: https://github.com/streetsidesoftware/cspell/tree/master/packages/cspell
 {
  "version": "0.2",
+  "import": [
+    "@cspell/dict-en_us/cspell-ext.json",
+    // "@cspell/dict-cpp/cspell-ext.json",
+    "@cspell/dict-python/cspell-ext.json",
+    "@cspell/dict-rust/cspell-ext.json",
+    "@cspell/dict-win32/cspell-ext.json",
+    "@cspell/dict-shell/cspell-ext.json",
+  ],
  // language - current active spelling language
  "language": "en",
  // dictionaries - list of the names of the dictionaries to use
  "dictionaries": [
+    "cpython",  // Sometimes keeping same terms with cpython is easy
+    "python-more",  // Python API terms not listed in python
+    "rust-more",  // Rust API terms not listed in rust
    "en_US",
    "softwareTerms",
    "c",
    "cpp",
    "python",
-    "python-custom",
    "rust",
-    "unix",
-    "posix",
-    "winapi"
+    "shell",
+    "win32"
  ],
  // dictionaryDefinitions - this list defines any custom dictionaries to use
-  "dictionaryDefinitions": [],
+  "dictionaryDefinitions": [
+    {
+      "name": "cpython",
+      "path": "./.cspell.dict/cpython.txt"
+    },
+    {
+      "name": "python-more",
+      "path": "./.cspell.dict/python-more.txt"
+    },
+    {
+      "name": "rust-more",
+      "path": "./.cspell.dict/rust-more.txt"
+    }
+  ],
  "ignorePaths": [
    "**/__pycache__/**",
+    "target/**",
    "Lib/**"
  ],
  // words - list of words to be always considered correct
  "words": [
-    // Rust
-    "ahash",
-    "bidi",
-    "biguint",
-    "bindgen",
-    "bitflags",
-    "bstr",
-    "byteorder",
-    "chrono",
-    "consts",
-    "cstring",
-    "flate2",
-    "fract",
-    "hasher",
-    "idents",
-    "indexmap",
-    "insta",
-    "keccak",
-    "lalrpop",
-    "libc",
-    "libz",
-    "longlong",
-    "Manually",
-    "maplit",
-    "memmap",
-    "metas",
-    "modpow",
-    "nanos",
-    "peekable",
-    "powc",
-    "powf",
-    "prepended",
-    "punct",
-    "replacen",
-    "rsplitn",
-    "rustc",
-    "rustfmt",
-    "seekfrom",
-    "splitn",
-    "subsec",
-    "timsort",
-    "trai",
-    "ulonglong",
-    "unic",
-    "unistd",
-    "winapi",
-    "winsock",
-    // Python
-    "abstractmethods",
-    "aiter",
-    "anext",
-    "arrayiterator",
-    "arraytype",
-    "asend",
-    "athrow",
-    "basicsize",
-    "cformat",
-    "classcell",
-    "closesocket",
-    "codepoint",
-    "codepoints",
-    "cpython",
-    "decompressor",
-    "defaultaction",
-    "descr",
-    "dictcomp",
-    "dictitems",
-    "dictkeys",
-    "dictview",
-    "docstring",
-    "docstrings",
-    "dunder",
-    "eventmask",
-    "fdel",
-    "fget",
-    "fileencoding",
-    "fillchar",
-    "finallyhandler",
-    "frombytes",
-    "fromhex",
-    "fromunicode",
-    "fset",
-    "fspath",
-    "fstring",
-    "fstrings",
-    "genexpr",
-    "getattro",
-    "getformat",
-    "getnewargs",
-    "getweakrefcount",
-    "getweakrefs",
-    "hostnames",
-    "idiv",
-    "impls",
-    "infj",
-    "instancecheck",
-    "instanceof",
-    "isabstractmethod",
-    "itemiterator",
-    "itemsize",
-    "iternext",
-    "keyiterator",
-    "kwarg",
-    "kwargs",
-    "linearization",
-    "linearize",
-    "listcomp",
-    "mappingproxy",
-    "maxsplit",
-    "memoryview",
-    "memoryviewiterator",
-    "metaclass",
-    "metaclasses",
-    "metatype",
-    "mro",
-    "mros",
-    "nanj",
-    "ndigits",
-    "ndim",
-    "nonbytes",
-    "origname",
-    "posixsubprocess",
-    "pyexpat",
-    "PYTHONDEBUG",
-    "PYTHONHOME",
-    "PYTHONINSPECT",
-    "PYTHONOPTIMIZE",
-    "PYTHONPATH",
-    "PYTHONPATH",
-    "PYTHONVERBOSE",
-    "PYTHONWARNINGS",
-    "qualname",
-    "radd",
-    "rdiv",
-    "rdivmod",
-    "reconstructor",
-    "reversevalueiterator",
-    "rfloordiv",
-    "rlshift",
-    "rmod",
-    "rpow",
-    "rrshift",
-    "rsub",
-    "rtruediv",
-    "scproxy",
-    "setattro",
-    "setcomp",
-    "stacklevel",
-    "subclasscheck",
-    "subclasshook",
-    "unionable",
-    "unraisablehook",
-    "valueiterator",
-    "vararg",
-    "varargs",
-    "varnames",
-    "warningregistry",
-    "warnopts",
-    "weakproxy",
-    "xopts",
-    // RustPython
+    "RUSTPYTHONPATH",
+    // RustPython terms
+    "aiterable",
+    "alnum",
    "baseclass",
+    "boxvec",
    "Bytecode",
    "cfgs",
    "codegen",
+    "coro",
    "dedentations",
    "dedents",
    "deduped",
+    "downcastable",
    "downcasted",
    "dumpable",
+    "emscripten",
+    "excs",
+    "finalizer",
    "GetSet",
+    "groupref",
    "internable",
+    "jitted",
+    "jitting",
+    "lossily",
    "makeunicodedata",
    "miri",
    "notrace",
+    "openat",
    "pyarg",
    "pyarg",
    "pyargs",
+    "pyast",
    "PyAttr",
    "pyc",
    "PyClass",
@@ -210,6 +88,8 @@
    "PyFunction",
    "pygetset",
    "pyimpl",
+    "pylib",
+    "pymath",
    "pymember",
    "PyMethod",
    "PyModule",
@@ -222,6 +102,7 @@
    "PyResult",
    "pyslot",
    "PyStaticMethod",
+    "pystone",
    "pystr",
    "pystruct",
    "pystructseq",
@@ -229,57 +110,33 @@
    "reducelib",
    "richcompare",
    "RustPython",
+    "significand",
    "struc",
+    "summands", // plural of summand
+    "sysmodule",
    "tracebacks",
    "typealiases",
-    "Unconstructible",
+    "unconstructible",
    "unhashable",
    "uninit",
    "unraisable",
+    "unresizable",
    "wasi",
    "zelf",
-    // cpython
-    "argtypes",
-    "asdl",
-    "asname",
-    "augassign",
-    "badsyntax",
-    "basetype",
-    "boolop",
-    "bxor",
-    "cellarg",
-    "cellvar",
-    "cellvars",
-    "cmpop",
-    "dictoffset",
-    "elts",
-    "excepthandler",
-    "finalbody",
-    "freevar",
-    "freevars",
-    "fromlist",
-    "heaptype",
-    "IMMUTABLETYPE",
-    "kwonlyarg",
-    "kwonlyargs",
-    "linearise",
-    "maxdepth",
-    "mult",
-    "nkwargs",
-    "orelse",
-    "patma",
-    "posonlyarg",
-    "posonlyargs",
-    "prec",
-    "stackdepth",
-    "unaryop",
-    "unparse",
-    "unparser",
-    "VARKEYWORDS",
-    "varkwarg",
-    "wbits",
-    "withitem",
-    "withs"
+    // unix
+    "CLOEXEC",
+    "codeset",
+    "endgrent",
+    "gethrvtime",
+    "getrusage",
+    "nanosleep",
+    "sigaction",
+    "WRLCK",
+    // win32
+    "birthtime",
+    "IFEXEC",
+    // "stat"
+    "FIRMLINK"
  ],
  // flagWords - list of words to be always considered incorrect
  "flagWords": [
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -0,0 +1,6 @@
+FROM mcr.microsoft.com/vscode/devcontainers/rust:1-bullseye
+
+# Install clang
+RUN apt-get update \
+  && apt-get install -y clang \
+  && rm -rf /var/lib/apt/lists/*
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -1,6 +1,25 @@
 {
-  "image": "mcr.microsoft.com/devcontainers/universal:2",
-  "features": {
-    "ghcr.io/devcontainers/features/rust:1": {}
-  }
+  "name": "Rust",
+  "build": {
+    "dockerfile": "Dockerfile"
+  },
+  "runArgs": ["--cap-add=SYS_PTRACE", "--security-opt", "seccomp=unconfined"],
+  "customizations": {
+    "vscode": {
+      "settings": {
+        "lldb.executable": "/usr/bin/lldb",
+        // VS Code don't watch files under ./target
+        "files.watcherExclude": {
+          "**/target/**": true
+        },
+        "extensions": [
+          "rust-lang.rust-analyzer",
+          "tamasfe.even-better-toml",
+          "vadimcn.vscode-lldb",
+          "mutantdino.resourcemonitor"
+        ]
+      }
+    }
+  },
+  "remoteUser": "vscode"
 }
--- a/.gemini/config.yaml
+++ b/.gemini/config.yaml
@@ -0,0 +1,2 @@
+ignore_patterns:
+  - "Lib/**"
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,6 +1,7 @@
 Lib/**      linguist-vendored
-Cargo.lock  linguist-generated -merge
+Cargo.lock  linguist-generated
 *.snap      linguist-generated -merge
 vm/src/stdlib/ast/gen.rs    linguist-generated -merge
 Lib/*.py    text working-tree-encoding=UTF-8 eol=LF
 **/*.rs     text working-tree-encoding=UTF-8 eol=LF
+*.pck       binary
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,212 @@
+# GitHub Copilot Instructions for RustPython
+
+This document provides guidelines for working with GitHub Copilot when contributing to the RustPython project.
+
+## Project Overview
+
+RustPython is a Python 3 interpreter written in Rust, implementing Python 3.13.0+ compatibility. The project aims to provide:
+
+- A complete Python-3 environment entirely in Rust (not CPython bindings)
+- A clean implementation without compatibility hacks
+- Cross-platform support, including WebAssembly compilation
+- The ability to embed Python scripting in Rust applications
+
+## Repository Structure
+
+- `src/` - Top-level code for the RustPython binary
+- `vm/` - The Python virtual machine implementation
+  - `builtins/` - Python built-in types and functions
+  - `stdlib/` - Essential standard library modules implemented in Rust, required to run the Python core
+- `compiler/` - Python compiler components
+  - `parser/` - Parser for converting Python source to AST
+  - `core/` - Bytecode representation in Rust structures
+  - `codegen/` - AST to bytecode compiler
+- `Lib/` - CPython's standard library in Python (copied from CPython). **IMPORTANT**: Do not edit this directory directly; The only allowed operation is copying files from CPython.
+- `derive/` - Rust macros for RustPython
+- `common/` - Common utilities
+- `extra_tests/` - Integration tests and snippets
+- `stdlib/` - Non-essential Python standard library modules implemented in Rust (useful but not required for core functionality)
+- `wasm/` - WebAssembly support
+- `jit/` - Experimental JIT compiler implementation
+- `pylib/` - Python standard library packaging (do not modify this directory directly - its contents are generated automatically)
+
+## Important Development Notes
+
+### Running Python Code
+
+When testing Python code, always use RustPython instead of the standard `python` command:
+
+```bash
+# Use this instead of python script.py
+cargo run -- script.py
+
+# For interactive REPL
+cargo run
+
+# With specific features
+cargo run --features ssl
+
+# Release mode (recommended for better performance)
+cargo run --release -- script.py
+```
+
+### Comparing with CPython
+
+When you need to compare behavior with CPython or run test suites:
+
+```bash
+# Use python command to explicitly run CPython
+python my_test_script.py
+
+# Run RustPython
+cargo run -- my_test_script.py
+```
+
+### Working with the Lib Directory
+
+The `Lib/` directory contains Python standard library files copied from the CPython repository. Important notes:
+
+- These files should be edited very conservatively
+- Modifications should be minimal and only to work around RustPython limitations
+- Tests in `Lib/test` often use one of the following markers:
+  - Add a `# TODO: RUSTPYTHON` comment when modifications are made
+  - `unittest.skip("TODO: RustPython <reason>")`
+  - `unittest.expectedFailure` with `# TODO: RUSTPYTHON <reason>` comment
+
+### Testing
+
+```bash
+# Run Rust unit tests
+cargo test --workspace --exclude rustpython_wasm
+
+# Run Python snippets tests
+cd extra_tests
+pytest -v
+
+# Run the Python test module
+cargo run --release -- -m test ${TEST_MODULE}
+cargo run --release -- -m test test_unicode # to test test_unicode.py
+
+# Run the Python test module with specific function
+cargo run --release -- -m test test_unicode -k test_unicode_escape
+```
+
+### Determining What to Implement
+
+Run `./whats_left.py` to get a list of unimplemented methods, which is helpful when looking for contribution opportunities.
+
+## Coding Guidelines
+
+### Rust Code
+
+- Follow the default rustfmt code style (`cargo fmt` to format)
+- **IMPORTANT**: Always run clippy to lint code (`cargo clippy`) before completing tasks. Fix any warnings or lints that are introduced by your changes
+- Follow Rust best practices for error handling and memory management
+- Use the macro system (`pyclass`, `pymodule`, `pyfunction`, etc.) when implementing Python functionality in Rust
+
+### Python Code
+
+- **IMPORTANT**: In most cases, Python code should not be edited. Bug fixes should be made through Rust code modifications only
+- Follow PEP 8 style for custom Python code
+- Use ruff for linting Python code
+- Minimize modifications to CPython standard library files
+
+## Integration Between Rust and Python
+
+The project provides several mechanisms for integration:
+
+- `pymodule` macro for creating Python modules in Rust
+- `pyclass` macro for implementing Python classes in Rust
+- `pyfunction` macro for exposing Rust functions to Python
+- `PyObjectRef` and other types for working with Python objects in Rust
+
+## Common Patterns
+
+### Implementing a Python Module in Rust
+
+```rust
+#[pymodule]
+mod mymodule {
+    use rustpython_vm::prelude::*;
+
+    #[pyfunction]
+    fn my_function(value: i32) -> i32 {
+        value * 2
+    }
+
+    #[pyattr]
+    #[pyclass(name = "MyClass")]
+    #[derive(Debug, PyPayload)]
+    struct MyClass {
+        value: usize,
+    }
+
+    #[pyclass]
+    impl MyClass {
+        #[pymethod]
+        fn get_value(&self) -> usize {
+            self.value
+        }
+    }
+}
+```
+
+### Adding a Python Module to the Interpreter
+
+```rust
+vm.add_native_module(
+    "my_module_name".to_owned(),
+    Box::new(my_module::make_module),
+);
+```
+
+## Building for Different Targets
+
+### WebAssembly
+
+```bash
+# Build for WASM
+cargo build --target wasm32-wasip1 --no-default-features --features freeze-stdlib,stdlib --release
+```
+
+### JIT Support
+
+```bash
+# Enable JIT support
+cargo run --features jit
+```
+
+### SSL Support
+
+```bash
+# Enable SSL support
+cargo run --features ssl
+```
+
+## Test Code Modification Rules
+
+**CRITICAL: Test code modification restrictions**
+- NEVER comment out or delete any test code lines except for removing `@unittest.expectedFailure` decorators and upper TODO comments
+- NEVER modify test assertions, test logic, or test data
+- When a test cannot pass due to missing language features, keep it as expectedFailure and document the reason
+- The only acceptable modifications to test files are:
+  1. Removing `@unittest.expectedFailure` decorators and the upper TODO comments when tests actually pass
+  2. Adding `@unittest.expectedFailure` decorators when tests cannot be fixed
+
+**Examples of FORBIDDEN modifications:**
+- Commenting out test lines
+- Changing test assertions
+- Modifying test data or expected results
+- Removing test logic
+
+**Correct approach when tests fail due to unsupported syntax:**
+- Keep the test as `@unittest.expectedFailure`
+- Document that it requires PEP 695 support
+- Focus on tests that can be fixed through Rust code changes only
+
+## Documentation
+
+- Check the [architecture document](/architecture/architecture.md) for a high-level overview
+- Read the [development guide](/DEVELOPMENT.md) for detailed setup instructions
+- Generate documentation with `cargo doc --no-deps --all`
+- Online documentation is available at [docs.rs/rustpython](https://docs.rs/rustpython/)
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -0,0 +1,15 @@
+version: 2
+updates:
+  - package-ecosystem: cargo
+    directory: /
+    schedule:
+      interval: weekly
+    ignore:
+      # TODO: Remove when we use ruff from crates.io
+      # for some reason dependabot only updates the Cargo.lock file when dealing
+      # with git dependencies. i.e. not updating the version in Cargo.toml
+      - dependency-name: "ruff_*" 
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -4,6 +4,7 @@ on:
  pull_request:
    types: [unlabeled, opened, synchronize, reopened]
  merge_group:
+  workflow_dispatch:

 name: CI

@@ -15,26 +16,26 @@ concurrency:
  cancel-in-progress: true

 env:
-  CARGO_ARGS: --no-default-features --features stdlib,zlib,importlib,encodings,ssl,jit
+  CARGO_ARGS: --no-default-features --features stdlib,importlib,stdio,encodings,sqlite,ssl
  # Skip additional tests on Windows. They are checked on Linux and MacOS.
+  # test_glob: many failing tests
+  # test_io: many failing tests
+  # test_os: many failing tests
+  # test_pathlib: support.rmtree() failing
+  # test_posixpath: OSError: (22, 'The filename, directory name, or volume label syntax is incorrect. (os error 123)')
+  # test_venv: couple of failing tests
  WINDOWS_SKIPS: >-
    test_glob
-    test_importlib
    test_io
    test_os
+    test_rlcompleter
    test_pathlib
    test_posixpath
-    test_shutil
    test_venv
-  # configparser: https://github.com/RustPython/RustPython/issues/4995#issuecomment-1582397417
-  # socketserver: seems related to configparser crash.
-  MACOS_SKIPS: >-
-    test_configparser
-    test_socketserver
  # PLATFORM_INDEPENDENT_TESTS are tests that do not depend on the underlying OS. They are currently
  # only run on Linux to speed up the CI.
  PLATFORM_INDEPENDENT_TESTS: >-
-    test_argparse
+    test__colorize
    test_array
    test_asyncgen
    test_binop
@@ -59,7 +60,6 @@ env:
    test_dis
    test_enumerate
    test_exception_variations
-    test_exceptions
    test_float
    test_format
    test_fractions
@@ -100,12 +100,11 @@ env:
    test_tuple
    test_types
    test_unary
-    test_unicode
    test_unpack
    test_weakref
    test_yield_from
  # Python version targeted by the CI.
-  PYTHON_VERSION: "3.11.4"
+  PYTHON_VERSION: "3.13.1"

 jobs:
  rust_tests:
@@ -114,41 +113,48 @@ jobs:
      RUST_BACKTRACE: full
    name: Run rust tests
    runs-on:  ${{ matrix.os }}
+    timeout-minutes: ${{ contains(matrix.os, 'windows') && 45 || 30 }}
    strategy:
      matrix:
        os: [macos-latest, ubuntu-latest, windows-latest]
      fail-fast: false
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
      - uses: dtolnay/rust-toolchain@stable
        with:
          components: clippy
+      - uses: Swatinem/rust-cache@v2
+
      - name: Set up the Windows environment
        shell: bash
        run: |
-          choco install llvm openssl --no-progress
-          echo "OPENSSL_DIR=C:\Program Files\OpenSSL" >>$GITHUB_ENV
+          git config --system core.longpaths true
+          cargo install --target-dir=target -v cargo-vcpkg
+          cargo vcpkg -v build
        if: runner.os == 'Windows'
      - name: Set up the Mac environment
        run: brew install autoconf automake libtool
        if: runner.os == 'macOS'

-      - uses: Swatinem/rust-cache@v2
-
      - name: run clippy
-        run: cargo clippy ${{ env.CARGO_ARGS }} --workspace  --exclude rustpython_wasm -- -Dwarnings
+        run: cargo clippy ${{ env.CARGO_ARGS }} --workspace --all-targets --exclude rustpython_wasm -- -Dwarnings

      - name: run rust tests
        run: cargo test --workspace --exclude rustpython_wasm --verbose --features threading ${{ env.CARGO_ARGS }}
-        if: runner.os != 'macOS'  
-      # temp skip ssl linking for Mac to avoid CI failure
-      - name: run rust tests (MacOS no ssl)
-        run: cargo test --workspace --exclude rustpython_wasm --verbose --no-default-features --features threading,stdlib,zlib,importlib,encodings,jit
+        if: runner.os != 'macOS'
+      - name: run rust tests
+        run: cargo test --workspace --exclude rustpython_wasm --exclude rustpython-jit --verbose --features threading  ${{ env.CARGO_ARGS }}
        if: runner.os == 'macOS'

      - name: check compilation without threading
        run: cargo check ${{ env.CARGO_ARGS }}

+      - name: Test example projects
+        run:
+          cargo run --manifest-path example_projects/barebone/Cargo.toml
+          cargo run --manifest-path example_projects/frozen_stdlib/Cargo.toml
+        if: runner.os == 'Linux'
+
      - name: prepare AppleSilicon build
        uses: dtolnay/rust-toolchain@stable
        with:
@@ -170,8 +176,9 @@ jobs:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skip:ci') }}
    name: Ensure compilation on various targets
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
      - uses: dtolnay/rust-toolchain@stable
        with:
          target: i686-unknown-linux-gnu
@@ -211,13 +218,6 @@ jobs:
      - name: Check compilation for freebsd
        run: cargo check --target x86_64-unknown-freebsd

-      - uses: dtolnay/rust-toolchain@stable
-        with:
-          target: wasm32-unknown-unknown
-
-      - name: Check compilation for wasm32
-        run: cargo check --target wasm32-unknown-unknown --no-default-features
-
      - uses: dtolnay/rust-toolchain@stable
        with:
          target: x86_64-unknown-freebsd
@@ -225,12 +225,13 @@ jobs:
      - name: Check compilation for freeBSD
        run: cargo check --target x86_64-unknown-freebsd

-      - name: Prepare repository for redox compilation
-        run: bash scripts/redox/uncomment-cargo.sh
-      - name: Check compilation for Redox
-        uses: coolreader18/redoxer-action@v1
-        with:
-          command: check
+      # - name: Prepare repository for redox compilation
+      #   run: bash scripts/redox/uncomment-cargo.sh
+      # - name: Check compilation for Redox
+      #   uses: coolreader18/redoxer-action@v1
+      #   with:
+      #     command: check
+      #     args: --ignore-rust-version

  snippets_cpython:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skip:ci') }}
@@ -238,30 +239,35 @@ jobs:
      RUST_BACKTRACE: full
    name: Run snippets and cpython tests
    runs-on:  ${{ matrix.os }}
+    timeout-minutes: ${{ contains(matrix.os, 'windows') && 45 || 30 }}
    strategy:
      matrix:
        os: [macos-latest, ubuntu-latest, windows-latest]
      fail-fast: false
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
      - uses: dtolnay/rust-toolchain@stable
-      - uses: actions/setup-python@v4
+      - uses: Swatinem/rust-cache@v2
+      - uses: actions/setup-python@v6
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - name: Set up the Windows environment
        shell: bash
        run: |
-          choco install llvm openssl --no-progress
-          echo "OPENSSL_DIR=C:\Program Files\OpenSSL" >>$GITHUB_ENV
+          git config --system core.longpaths true
+          cargo install cargo-vcpkg
+          cargo vcpkg build
        if: runner.os == 'Windows'
      - name: Set up the Mac environment
        run: brew install autoconf automake libtool openssl@3
        if: runner.os == 'macOS'
-
-      - uses: Swatinem/rust-cache@v2
      - name: build rustpython
        run: cargo build --release --verbose --features=threading ${{ env.CARGO_ARGS }}
-      - uses: actions/setup-python@v4
+        if: runner.os == 'macOS'
+      - name: build rustpython
+        run: cargo build --release --verbose --features=threading ${{ env.CARGO_ARGS }},jit
+        if: runner.os != 'macOS'
+      - uses: actions/setup-python@v6
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - name: run snippets
@@ -276,16 +282,17 @@ jobs:
        run: target/release/rustpython -m test -j 1 -u all --slowest --fail-env-changed -v -x ${{ env.PLATFORM_INDEPENDENT_TESTS }}
      - if: runner.os == 'macOS'
        name: run cpython platform-dependent tests (MacOS)
-        run: target/release/rustpython -m test -j 1 -u all --slowest --fail-env-changed -v -x ${{ env.PLATFORM_INDEPENDENT_TESTS }} ${{ env.MACOS_SKIPS }}
+        run: target/release/rustpython -m test -j 1 --slowest --fail-env-changed -v -x ${{ env.PLATFORM_INDEPENDENT_TESTS }}
      - if: runner.os == 'Windows'
        name: run cpython platform-dependent tests (windows partial - fixme)
        run:
-          target/release/rustpython -m test -j 1 -u all --slowest --fail-env-changed -v -x ${{ env.PLATFORM_INDEPENDENT_TESTS }} ${{ env.WINDOWS_SKIPS }}
+          target/release/rustpython -m test -j 1 --slowest --fail-env-changed -v -x ${{ env.PLATFORM_INDEPENDENT_TESTS }} ${{ env.WINDOWS_SKIPS }}
      - if: runner.os != 'Windows'
        name: check that --install-pip succeeds
        run: |
          mkdir site-packages
          target/release/rustpython --install-pip ensurepip --user
+          target/release/rustpython -m pip install six
      - if: runner.os != 'Windows'
        name: Check that ensurepip succeeds.
        run: |
@@ -303,50 +310,70 @@ jobs:
    name: Check Rust code with rustfmt and clippy
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
      - uses: dtolnay/rust-toolchain@stable
        with:
            components: rustfmt, clippy
      - name: run rustfmt
-        run: cargo fmt --all -- --check
+        run: cargo fmt --check
      - name: run clippy on wasm
        run: cargo clippy --manifest-path=wasm/lib/Cargo.toml -- -Dwarnings
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v6
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - name: install ruff
-        run: python -m pip install ruff
-      - name: run python lint
-        run: ruff extra_tests wasm examples  --exclude='./.*',./Lib,./vm/Lib,./benches/ --select=E9,F63,F7,F82 --show-source
+        run: python -m pip install ruff==0.11.8
+      - name: Ensure docs generate no warnings
+        run: cargo doc
+      - name: run ruff check
+        run: ruff check --diff
+      - name: run ruff format
+        run: ruff format --check
      - name: install prettier
        run: yarn global add prettier && echo "$(yarn global bin)" >>$GITHUB_PATH
      - name: check wasm code with prettier
        # prettier doesn't handle ignore files very well: https://github.com/prettier/prettier/issues/8506
        run: cd wasm && git ls-files -z | xargs -0 prettier --check -u
+      # Keep cspell check as the last step. This is optional test.
+      - name: install extra dictionaries
+        run: npm install @cspell/dict-en_us @cspell/dict-cpp @cspell/dict-python @cspell/dict-rust @cspell/dict-win32 @cspell/dict-shell
+      - name: spell checker
+        uses: streetsidesoftware/cspell-action@v7
+        with:
+          files: '**/*.rs'
+          incremental_files_only: true

  miri:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skip:ci') }}
    name: Run tests under miri
    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    env:
+      NIGHTLY_CHANNEL: nightly
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
+
      - uses: dtolnay/rust-toolchain@master
        with:
-            toolchain: nightly
+            toolchain: ${{ env.NIGHTLY_CHANNEL }}
            components: miri

      - uses: Swatinem/rust-cache@v2
+
      - name: Run tests under miri
+        run: cargo +${{ env.NIGHTLY_CHANNEL }} miri test -p rustpython-vm -- miri_test
+        env:
        # miri-ignore-leaks because the type-object circular reference means that there will always be
        # a memory leak, at least until we have proper cyclic gc
-        run: MIRIFLAGS='-Zmiri-ignore-leaks' cargo +nightly miri test -p rustpython-vm -- miri_test
+          MIRIFLAGS: '-Zmiri-ignore-leaks'

  wasm:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skip:ci') }}
    name: Check the WASM package and demo
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
      - uses: dtolnay/rust-toolchain@stable

      - uses: Swatinem/rust-cache@v2
@@ -354,15 +381,18 @@ jobs:
        run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
      - name: install geckodriver
        run: |
-          wget https://github.com/mozilla/geckodriver/releases/download/v0.30.0/geckodriver-v0.30.0-linux64.tar.gz
+          wget https://github.com/mozilla/geckodriver/releases/download/v0.36.0/geckodriver-v0.36.0-linux64.tar.gz
          mkdir geckodriver
-          tar -xzf geckodriver-v0.30.0-linux64.tar.gz -C geckodriver
-      - uses: actions/setup-python@v4
+          tar -xzf geckodriver-v0.36.0-linux64.tar.gz -C geckodriver
+      - uses: actions/setup-python@v6
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - run: python -m pip install -r requirements.txt
        working-directory: ./wasm/tests
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v5
+        with:
+          cache: "npm"
+          cache-dependency-path: "wasm/demo/package-lock.json"
      - name: run test
        run: |
          export PATH=$PATH:`pwd`/../../geckodriver
@@ -371,6 +401,15 @@ jobs:
        env:
          NODE_OPTIONS: "--openssl-legacy-provider"
        working-directory: ./wasm/demo
+      - uses: mwilliamson/setup-wabt-action@v3
+        with: { wabt-version: "1.0.36" }
+      - name: check wasm32-unknown without js
+        run: |
+          cd wasm/wasm-unknown-test
+          cargo build --release --verbose
+          if wasm-objdump -xj Import target/wasm32-unknown-unknown/release/wasm_unknown_test.wasm; then
+            echo "ERROR: wasm32-unknown module expects imports from the host environment" >2
+          fi
      - name: build notebook demo
        if: github.ref == 'refs/heads/release'
        run: |
@@ -382,7 +421,7 @@ jobs:
        working-directory: ./wasm/notebook
      - name: Deploy demo to Github Pages
        if: success() && github.ref == 'refs/heads/release'
-        uses: peaceiris/actions-gh-pages@v2
+        uses: peaceiris/actions-gh-pages@v4
        env:
          ACTIONS_DEPLOY_KEY: ${{ secrets.ACTIONS_DEMO_DEPLOY_KEY }}
          PUBLISH_DIR: ./wasm/demo/dist
@@ -393,18 +432,21 @@ jobs:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'skip:ci') }}
    name: Run snippets and cpython tests on wasm-wasi
    runs-on: ubuntu-latest
+    timeout-minutes: 30
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
      - uses: dtolnay/rust-toolchain@stable
        with:
-          target: wasm32-wasi
+          target: wasm32-wasip1

      - uses: Swatinem/rust-cache@v2
      - name: Setup Wasmer
-        uses: wasmerio/setup-wasmer@v2
+        uses: wasmerio/setup-wasmer@v3
      - name: Install clang
        run: sudo apt-get update && sudo apt-get install clang -y
      - name: build rustpython
-        run: cargo build --release --target wasm32-wasi --features freeze-stdlib,stdlib --verbose
+        run: cargo build --release --target wasm32-wasip1 --features freeze-stdlib,stdlib --verbose
      - name: run snippets
-        run: wasmer run --dir . target/wasm32-wasi/release/rustpython.wasm -- extra_tests/snippets/stdlib_random.py
+        run: wasmer run --dir `pwd` target/wasm32-wasip1/release/rustpython.wasm -- `pwd`/extra_tests/snippets/stdlib_random.py
+      - name: run cpython unittest
+        run: wasmer run --dir `pwd` target/wasm32-wasip1/release/rustpython.wasm -- `pwd`/Lib/test/test_int.py
--- a/.github/workflows/comment-commands.yml
+++ b/.github/workflows/comment-commands.yml
@@ -0,0 +1,21 @@
+name: Comment Commands
+
+on:
+  issue_comment:
+    types: created
+
+jobs:
+  issue_assign:
+    if: (!github.event.issue.pull_request) && github.event.comment.body == 'take'
+    runs-on: ubuntu-latest
+
+    concurrency:
+      group: ${{ github.actor }}-issue-assign
+
+    permissions:
+      issues: write
+
+    steps:
+      # Using REST API and not `gh issue edit`. https://github.com/cli/cli/issues/6235#issuecomment-1243487651
+      - run: |
+          curl -H "Authorization: token ${{ github.token }}" -d '{"assignees": ["${{ github.event.comment.user.login }}"]}' https://api.github.com/repos/${{ github.repository }}/issues/${{ github.event.issue.number }}/assignees
--- a/.github/workflows/cron-ci.yaml
+++ b/.github/workflows/cron-ci.yaml
@@ -2,12 +2,15 @@ on:
  schedule:
    - cron: '0 0 * * 6'
  workflow_dispatch:
+  push:
+    paths:
+      - .github/workflows/cron-ci.yaml

 name: Periodic checks/tasks

 env:
-  CARGO_ARGS: --no-default-features --features stdlib,zlib,importlib,encodings,ssl,jit
-  PYTHON_VERSION: "3.11.4"
+  CARGO_ARGS: --no-default-features --features stdlib,importlib,encodings,ssl,jit
+  PYTHON_VERSION: "3.13.1"

 jobs:
  # codecov collects code coverage data from the rust tests, python snippets and python test suite.
@@ -15,16 +18,18 @@ jobs:
  codecov:
    name: Collect code coverage data
    runs-on: ubuntu-latest
+    # Disable this scheduled job when running on a fork.
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: taiki-e/install-action@cargo-llvm-cov
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - run: sudo apt-get update && sudo apt-get -y install lcov
      - name: Run cargo-llvm-cov with Rust tests.
-        run: cargo llvm-cov --no-report --workspace --exclude rustpython_wasm --verbose --no-default-features --features stdlib,zlib,importlib,encodings,ssl,jit
+        run: cargo llvm-cov --no-report --workspace --exclude rustpython_wasm --verbose --no-default-features --features stdlib,importlib,encodings,ssl,jit
      - name: Run cargo-llvm-cov with Python snippets.
        run: python scripts/cargo-llvm-cov.py
        continue-on-error: true
@@ -34,15 +39,17 @@ jobs:
      - name: Prepare code coverage data
        run: cargo llvm-cov report --lcov --output-path='codecov.lcov'
      - name: Upload to Codecov
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v5
        with:
          file: ./codecov.lcov

  testdata:
    name: Collect regression test data
    runs-on: ubuntu-latest
+    # Disable this scheduled job when running on a fork.
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - name: build rustpython
        run: cargo build --release --verbose
@@ -70,10 +77,12 @@ jobs:
  whatsleft:
    name: Collect what is left data
    runs-on: ubuntu-latest
+    # Disable this scheduled job when running on a fork.
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - name: build rustpython
@@ -81,7 +90,7 @@ jobs:
      - name: Collect what is left data
        run: |
          chmod +x ./whats_left.py
-          ./whats_left.py > whats_left.temp
+          ./whats_left.py --features "ssl,sqlite" > whats_left.temp
        env:
          RUSTPYTHONPATH: ${{ github.workspace }}/Lib
      - name: Upload data to the website
@@ -97,6 +106,9 @@ jobs:
          cd website
          [ -f ./_data/whats_left.temp ] && cp ./_data/whats_left.temp ./_data/whats_left_lastrun.temp
          cp ../whats_left.temp ./_data/whats_left.temp
+          rm ./_data/whats_left/modules.csv
+          echo -e "module" > ./_data/whats_left/modules.csv
+          cat ./_data/whats_left.temp | grep "(entire module)" | cut -d ' ' -f 1 | sort >> ./_data/whats_left/modules.csv
          git add -A
          if git -c user.name="Github Actions" -c user.email="actions@github.com" commit -m "Update what is left results" --author="$GITHUB_ACTOR"; then
            git push
@@ -105,10 +117,12 @@ jobs:
  benchmark:
    name: Collect benchmark data
    runs-on: ubuntu-latest
+    # Disable this scheduled job when running on a fork.
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
        with:
          python-version: 3.9
      - run: cargo install cargo-criterion
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -0,0 +1,179 @@
+name: Release
+
+on:
+  schedule:
+    # 9 AM UTC on every Monday
+    - cron: "0 9 * * Mon"
+  workflow_dispatch:
+    inputs:
+      pre-release:
+        type: boolean
+        description: Mark "Pre-Release"
+        required: false
+        default: true
+
+permissions:
+  contents: write
+
+env:
+  CARGO_ARGS: --no-default-features --features stdlib,importlib,encodings,sqlite,ssl
+
+jobs:
+  build:
+    runs-on: ${{ matrix.platform.runner }}
+    # Disable this scheduled job when running on a fork.
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
+    strategy:
+      matrix:
+        platform:
+          - runner: ubuntu-latest
+            target: x86_64-unknown-linux-gnu
+#          - runner: ubuntu-latest
+#            target: i686-unknown-linux-gnu
+#          - runner: ubuntu-latest
+#            target: aarch64-unknown-linux-gnu
+#          - runner: ubuntu-latest
+#            target: armv7-unknown-linux-gnueabi
+#          - runner: ubuntu-latest
+#            target: s390x-unknown-linux-gnu
+#          - runner: ubuntu-latest
+#            target: powerpc64le-unknown-linux-gnu
+          - runner: macos-latest
+            target: aarch64-apple-darwin
+#          - runner: macos-latest
+#            target: x86_64-apple-darwin
+          - runner: windows-latest
+            target: x86_64-pc-windows-msvc
+#          - runner: windows-latest
+#            target: i686-pc-windows-msvc
+#          - runner: windows-latest
+#            target: aarch64-pc-windows-msvc
+      fail-fast: false
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: cargo-bins/cargo-binstall@main
+
+      - name: Set up Environment
+        shell: bash
+        run: rustup target add ${{ matrix.platform.target }}
+      - name: Set up Windows Environment
+        shell: bash
+        run: |
+          git config --global core.longpaths true
+          cargo install --target-dir=target -v cargo-vcpkg
+          cargo vcpkg -v build
+        if: runner.os == 'Windows'
+      - name: Set up MacOS Environment
+        run: brew install autoconf automake libtool
+        if: runner.os == 'macOS'
+
+      - name: Build RustPython
+        run: cargo build --release --target=${{ matrix.platform.target }} --verbose --features=threading ${{ env.CARGO_ARGS }}
+        if: runner.os == 'macOS'
+      - name: Build RustPython
+        run: cargo build --release --target=${{ matrix.platform.target }} --verbose --features=threading ${{ env.CARGO_ARGS }},jit
+        if: runner.os != 'macOS'
+
+      - name: Rename Binary
+        run: cp target/${{ matrix.platform.target }}/release/rustpython target/rustpython-release-${{ runner.os }}-${{ matrix.platform.target }}
+        if: runner.os != 'Windows'
+      - name: Rename Binary
+        run: cp target/${{ matrix.platform.target }}/release/rustpython.exe target/rustpython-release-${{ runner.os }}-${{ matrix.platform.target }}.exe
+        if: runner.os == 'Windows'
+
+      - name: Upload Binary Artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: rustpython-release-${{ runner.os }}-${{ matrix.platform.target }}
+          path: target/rustpython-release-${{ runner.os }}-${{ matrix.platform.target }}*
+
+  build-wasm:
+    runs-on: ubuntu-latest
+    # Disable this scheduled job when running on a fork.
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: wasm32-wasip1
+
+      - name: Build RustPython
+        run: cargo build --target wasm32-wasip1 --no-default-features --features freeze-stdlib,stdlib --release
+
+      - name: Rename Binary
+        run: cp target/wasm32-wasip1/release/rustpython.wasm target/rustpython-release-wasm32-wasip1.wasm
+
+      - name: Upload Binary Artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: rustpython-release-wasm32-wasip1
+          path: target/rustpython-release-wasm32-wasip1.wasm
+
+      - name: install wasm-pack
+        run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+      - uses: actions/setup-node@v5
+      - uses: mwilliamson/setup-wabt-action@v3
+        with: { wabt-version: "1.0.30" }
+      - name: build demo
+        run: |
+          npm install
+          npm run dist
+        env:
+          NODE_OPTIONS: "--openssl-legacy-provider"
+        working-directory: ./wasm/demo
+      - name: build notebook demo
+        run: |
+          npm install
+          npm run dist
+          mv dist ../demo/dist/notebook
+        env:
+          NODE_OPTIONS: "--openssl-legacy-provider"
+        working-directory: ./wasm/notebook
+      - name: Deploy demo to Github Pages
+        uses: peaceiris/actions-gh-pages@v4
+        with:
+          deploy_key: ${{ secrets.ACTIONS_DEMO_DEPLOY_KEY }}
+          publish_dir: ./wasm/demo/dist
+          external_repository: RustPython/demo
+          publish_branch: master
+
+  release:
+    runs-on: ubuntu-latest
+    # Disable this scheduled job when running on a fork.
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
+    needs: [build, build-wasm]
+    steps:
+      - name: Download Binary Artifacts
+        uses: actions/download-artifact@v5
+        with:
+          path: bin
+          pattern: rustpython-*
+          merge-multiple: true
+
+      - name: List Binaries
+        run: |
+          ls -lah bin/
+          file bin/*
+      - name: Create Release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          tag: ${{ github.ref_name }}
+          run: ${{ github.run_number }}
+        run: |
+          if [[ "${{ github.event.inputs.pre-release }}" == "false" ]]; then
+            RELEASE_TYPE_NAME=Release
+            PRERELEASE_ARG=
+          else
+            RELEASE_TYPE_NAME=Pre-Release
+            PRERELEASE_ARG=--prerelease
+          fi
+          
+          today=$(date '+%Y-%m-%d')
+          gh release create "$today-$tag-$run" \
+              --repo="$GITHUB_REPOSITORY" \
+              --title="RustPython $RELEASE_TYPE_NAME $today-$tag #$run" \
+              --target="$tag" \
+              --generate-notes \
+              $PRERELEASE_ARG \
+              bin/rustpython-release-*
--- a/.gitignore
+++ b/.gitignore
@@ -2,13 +2,15 @@
 /*/target
 **/*.rs.bk
 **/*.bytecode
-__pycache__
+__pycache__/
 **/*.pytest_cache
 .*sw*
 .repl_history.txt
-.vscode
+.vscode/
 wasm-pack.log
 .idea/
+.envrc
+.python-version

 flame-graph.html
 flame.txt
@@ -19,3 +21,8 @@ flamescope.json

 extra_tests/snippets/resources
 extra_tests/not_impl.py
+
+Lib/site-packages/*
+!Lib/site-packages/README.txt
+Lib/test/data/*
+!Lib/test/data/README
--- a/Cargo.lock
+++ b/Cargo.lock
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,113 +1,46 @@
 [package]
 name = "rustpython"
-version = "0.3.0"
-authors = ["RustPython Team"]
-edition = "2021"
-rust-version = "1.67.1"
 description = "A python interpreter written in rust."
-repository = "https://github.com/RustPython/RustPython"
-license = "MIT"
 include = ["LICENSE", "Cargo.toml", "src/**/*.rs"]
-
-[workspace]
-resolver = "2"
-members = [
-    "compiler", "compiler/core", "compiler/codegen",
-    ".", "common", "derive", "jit", "vm", "pylib", "stdlib", "wasm/lib", "derive-impl",
-]
-
-[workspace.dependencies]
-rustpython-compiler-core = { path = "compiler/core", version = "0.3.0" }
-rustpython-compiler = { path = "compiler", version = "0.3.0" }
-rustpython-codegen = { path = "compiler/codegen", version = "0.3.0" }
-rustpython-common = { path = "common", version = "0.3.0" }
-rustpython-derive = { path = "derive", version = "0.3.0" }
-rustpython-derive-impl = { path = "derive-impl", version = "0.3.0" }
-rustpython-jit = { path = "jit", version = "0.3.0" }
-rustpython-vm = { path = "vm", version = "0.3.0" }
-rustpython-pylib = { path = "pylib", version = "0.3.0" }
-rustpython-stdlib = { path = "stdlib", version = "0.3.0" }
-rustpython-doc = { git = "https://github.com/RustPython/__doc__", tag = "0.3.0", version = "0.3.0" }
-
-rustpython-literal = { git = "https://github.com/RustPython/Parser.git", tag = "0.3.0", version = "0.3.0" }
-rustpython-parser-core = { git = "https://github.com/RustPython/Parser.git", tag = "0.3.0", version = "0.3.0" }
-rustpython-parser = { git = "https://github.com/RustPython/Parser.git", tag = "0.3.0", version = "0.3.0" }
-rustpython-ast = { git = "https://github.com/RustPython/Parser.git", tag = "0.3.0", version = "0.3.0" }
-rustpython-format = { git = "https://github.com/RustPython/Parser.git", tag = "0.3.0", version = "0.3.0" }
-# rustpython-literal = { path = "../RustPython-parser/literal" }
-# rustpython-parser-core = { path = "../RustPython-parser/core" }
-# rustpython-parser = { path = "../RustPython-parser/parser" }
-# rustpython-ast = { path = "../RustPython-parser/ast" }
-# rustpython-format = { path = "../RustPython-parser/format" }
-
-ahash = "0.7.6"
-anyhow = "1.0.45"
-ascii = "1.0"
-atty = "0.2.14"
-bitflags = "2.2.1"
-bstr = "0.2.17"
-cfg-if = "1.0"
-chrono = "0.4.19"
-crossbeam-utils = "0.8.16"
-flame = "0.2.2"
-glob = "0.3"
-hex = "0.4.3"
-indexmap = "1.8.1"
-insta = "1.14.0"
-itertools = "0.10.3"
-libc = "0.2.133"
-log = "0.4.16"
-nix = "0.26"
-malachite-bigint = { version = "0.1.0" }
-malachite-q = "0.3.2"
-malachite-base = "0.3.2"
-num-complex = "0.4.0"
-num-integer = "0.1.44"
-num-traits = "0.2"
-num_enum = "0.5.7"
-once_cell = "1.13"
-parking_lot = "0.12"
-paste = "1.0.7"
-rand = "0.8.5"
-rustyline = "11"
-serde = "1.0"
-schannel = "0.1.19"
-static_assertions = "1.1"
-syn = "1.0.91"
-thiserror = "1.0"
-thread_local = "1.1.4"
-unicode_names2 = { version = "0.6.0", git = "https://github.com/youknowone/unicode_names2.git", rev = "4ce16aa85cbcdd9cc830410f1a72ef9a235f2fde" }
-widestring = "0.5.1"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+repository.workspace = true
+license.workspace = true

 [features]
-default = ["threading", "stdlib", "zlib", "importlib"]
+default = ["threading", "stdlib", "stdio", "importlib"]
 importlib = ["rustpython-vm/importlib"]
 encodings = ["rustpython-vm/encodings"]
+stdio = ["rustpython-vm/stdio"]
 stdlib = ["rustpython-stdlib", "rustpython-pylib", "encodings"]
 flame-it = ["rustpython-vm/flame-it", "flame", "flamescope"]
-freeze-stdlib = ["rustpython-vm/freeze-stdlib", "rustpython-pylib?/freeze-stdlib"]
+freeze-stdlib = ["stdlib", "rustpython-vm/freeze-stdlib", "rustpython-pylib?/freeze-stdlib"]
 jit = ["rustpython-vm/jit"]
 threading = ["rustpython-vm/threading", "rustpython-stdlib/threading"]
-zlib = ["stdlib", "rustpython-stdlib/zlib"]
-bz2 = ["stdlib", "rustpython-stdlib/bz2"]
+sqlite = ["rustpython-stdlib/sqlite"]
 ssl = ["rustpython-stdlib/ssl"]
-ssl-vendor = ["rustpython-stdlib/ssl-vendor"]
+ssl-vendor = ["ssl", "rustpython-stdlib/ssl-vendor"]
+tkinter = ["rustpython-stdlib/tkinter"]
+
+[build-dependencies]
+winresource = "0.1"

 [dependencies]
 rustpython-compiler = { workspace = true }
 rustpython-pylib = { workspace = true, optional = true }
-rustpython-stdlib = { workspace = true, optional = true }
-rustpython-vm = { workspace = true, default-features = false, features = ["compiler"] }
-rustpython-parser = { workspace = true }
+rustpython-stdlib = { workspace = true, optional = true, features = ["compiler"] }
+rustpython-vm = { workspace = true, features = ["compiler"] }
+ruff_python_parser = { workspace = true }

-atty = { workspace = true }
 cfg-if = { workspace = true }
 log = { workspace = true }
 flame = { workspace = true, optional = true }

-clap = "2.34"
-dirs = { package = "dirs-next", version = "2.0.0" }
-env_logger = { version = "0.9.0", default-features = false, features = ["atty", "termcolor"] }
+lexopt = "0.3"
+dirs = { package = "dirs-next", version = "2.0" }
+env_logger = "0.11"
 flamescope = { version = "0.1.2", optional = true }

 [target.'cfg(windows)'.dependencies]
@@ -117,9 +50,8 @@ libc = { workspace = true }
 rustyline = { workspace = true }

 [dev-dependencies]
-cpython = "0.7.0"
-criterion = "0.3.5"
-python3-sys = "0.7.1"
+criterion = { workspace = true }
+pyo3 = { version = "0.26", features = ["auto-initialize"] }

 [[bench]]
 name = "execution"
@@ -151,5 +83,161 @@ lto = "thin"

 [patch.crates-io]
 # REDOX START, Uncomment when you want to compile/check with redoxer
-# nix = { git = "https://github.com/coolreader18/nix", branch = "0.26.2-redox" }
 # REDOX END
+
+# Used only on Windows to build the vcpkg dependencies
+[package.metadata.vcpkg]
+git = "https://github.com/microsoft/vcpkg"
+# The revision of the vcpkg repository to use
+# https://github.com/microsoft/vcpkg/tags
+rev = "2024.02.14"
+
+[package.metadata.vcpkg.target]
+x86_64-pc-windows-msvc = { triplet = "x64-windows-static-md", dev-dependencies = ["openssl" ] }
+
+[package.metadata.packager]
+product-name = "RustPython"
+identifier = "com.rustpython.rustpython"
+description = "An open source Python 3 interpreter written in Rust"
+homepage = "https://rustpython.github.io/"
+license_file = "LICENSE"
+authors = ["RustPython Team"]
+publisher = "RustPython Team"
+resources = ["LICENSE", "README.md", "Lib"]
+icons = ["32x32.png"]
+
+[package.metadata.packager.nsis]
+installer_mode = "both"
+template = "installer-config/installer.nsi"
+
+[package.metadata.packager.wix]
+template = "installer-config/installer.wxs"
+
+
+[workspace]
+resolver = "2"
+members = [
+    "compiler",
+    "compiler/core",
+    "compiler/codegen",
+    "compiler/literal",
+    ".",
+    "common",
+    "derive",
+    "jit",
+    "vm",
+    "vm/sre_engine",
+    "pylib",
+    "stdlib",
+    "derive-impl",
+    "wtf8",
+    "wasm/lib",
+]
+
+[workspace.package]
+version = "0.4.0"
+authors = ["RustPython Team"]
+edition = "2024"
+rust-version = "1.89.0"
+repository = "https://github.com/RustPython/RustPython"
+license = "MIT"
+
+[workspace.dependencies]
+rustpython-compiler-core = { path = "compiler/core", version = "0.4.0" }
+rustpython-compiler = { path = "compiler", version = "0.4.0" }
+rustpython-codegen = { path = "compiler/codegen", version = "0.4.0" }
+rustpython-common = { path = "common", version = "0.4.0" }
+rustpython-derive = { path = "derive", version = "0.4.0" }
+rustpython-derive-impl = { path = "derive-impl", version = "0.4.0" }
+rustpython-jit = { path = "jit", version = "0.4.0" }
+rustpython-literal = { path = "compiler/literal", version = "0.4.0" }
+rustpython-vm = { path = "vm", default-features = false, version = "0.4.0" }
+rustpython-pylib = { path = "pylib", version = "0.4.0" }
+rustpython-stdlib = { path = "stdlib", default-features = false, version = "0.4.0" }
+rustpython-sre_engine = { path = "vm/sre_engine", version = "0.4.0" }
+rustpython-wtf8 = { path = "wtf8", version = "0.4.0" }
+rustpython-doc = { git = "https://github.com/RustPython/__doc__", tag = "0.3.0", version = "0.3.0" }
+
+ruff_python_parser = { git = "https://github.com/astral-sh/ruff.git", tag = "0.11.0" }
+ruff_python_ast = { git = "https://github.com/astral-sh/ruff.git", tag = "0.11.0" }
+ruff_text_size = { git = "https://github.com/astral-sh/ruff.git", tag = "0.11.0" }
+ruff_source_file = { git = "https://github.com/astral-sh/ruff.git", tag = "0.11.0" }
+
+ahash = "0.8.12"
+ascii = "1.1"
+bitflags = "2.9.4"
+bstr = "1"
+cfg-if = "1.0"
+chrono = "0.4.42"
+constant_time_eq = "0.4"
+criterion = { version = "0.7", features = ["html_reports"] }
+crossbeam-utils = "0.8.21"
+flame = "0.2.2"
+getrandom = { version = "0.3", features = ["std"] }
+glob = "0.3"
+hex = "0.4.3"
+indexmap = { version = "2.11.3", features = ["std"] }
+insta = "1.42"
+itertools = "0.14.0"
+is-macro = "0.3.7"
+junction = "1.3.0"
+libc = "0.2.169"
+libffi = "4.1"
+log = "0.4.28"
+nix = { version = "0.30", features = ["fs", "user", "process", "term", "time", "signal", "ioctl", "socket", "sched", "zerocopy", "dir", "hostname", "net", "poll"] }
+malachite-bigint = "0.6"
+malachite-q = "0.6"
+malachite-base = "0.6"
+memchr = "2.7.4"
+num-complex = "0.4.6"
+num-integer = "0.1.46"
+num-traits = "0.2"
+num_enum = { version = "0.7", default-features = false }
+optional = "0.5"
+once_cell = "1.20.3"
+parking_lot = "0.12.3"
+paste = "1.0.15"
+proc-macro2 = "1.0.93"
+pymath = "0.0.2"
+quote = "1.0.38"
+radium = "1.1.1"
+rand = "0.9"
+rand_core = { version = "0.9", features = ["os_rng"] }
+rustix = { version = "1.0", features = ["event"] }
+rustyline = "17.0.1"
+serde = { version = "1.0.225", default-features = false }
+schannel = "0.1.28"
+scoped-tls = "1"
+scopeguard = "1"
+static_assertions = "1.1"
+strum = "0.27"
+strum_macros = "0.27"
+syn = "2"
+thiserror = "2.0"
+thread_local = "1.1.9"
+unicode-casing = "0.1.1"
+unic-char-property = "0.9.0"
+unic-normal = "0.9.0"
+unic-ucd-age = "0.9.0"
+unic-ucd-bidi = "0.9.0"
+unic-ucd-category = "0.9.0"
+unic-ucd-ident = "0.9.0"
+unicode_names2 = "2.0.0"
+unicode-bidi-mirroring = "0.4"
+widestring = "1.2.0"
+windows-sys = "0.59.0"
+wasm-bindgen = "0.2.100"
+
+# Lints
+
+[workspace.lints.rust]
+unsafe_code = "allow"
+unsafe_op_in_unsafe_fn = "deny"
+elided_lifetimes_in_paths = "warn"
+
+[workspace.lints.clippy]
+perf = "warn"
+style = "warn"
+complexity = "warn"
+suspicious = "warn"
+correctness = "warn"
--- a/DEVELOPMENT.md
+++ b/DEVELOPMENT.md
@@ -25,7 +25,7 @@ RustPython requires the following:
      stable version: `rustup update stable`
    - If you do not have Rust installed, use [rustup](https://rustup.rs/) to
      do so.
- CPython version 3.11 or higher
+- CPython version 3.13 or higher
    - CPython can be installed by your operating system's package manager,
      from the [Python website](https://www.python.org/downloads/), or
      using a third-party distribution, such as 
--- a/2
+++ b/2
@@ -1,6 +1,6 @@
 MIT License

-Copyright (c) 2020 RustPython Team
+Copyright (c) 2025 RustPython Team

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
--- a/Lib/future.py
+++ b/Lib/future.py
@@ -33,7 +33,7 @@ in releases at or after that, modules no longer need
 to use the feature in question, but may continue to use such imports.

 MandatoryRelease may also be None, meaning that a planned feature got
-dropped.
+dropped or that the release version is undetermined.

 Instances of class _Feature have two corresponding methods,
 .getOptionalRelease() and .getMandatoryRelease().
@@ -96,7 +96,7 @@ class _Feature:
        """Return release in which this feature will become mandatory.

        This is a 5-tuple, of the same form as sys.version_info, or, if
-        the feature was dropped, is None.
+        the feature was dropped, or the release date is undetermined, is None.
        """
        return self.mandatory

@@ -143,5 +143,5 @@ generator_stop = _Feature((3, 5, 0, "beta", 1),
                          CO_FUTURE_GENERATOR_STOP)

 annotations = _Feature((3, 7, 0, "beta", 1),
-                       (3, 11, 0, "alpha", 0),
+                       None,
                       CO_FUTURE_ANNOTATIONS)
--- a/Lib/_aix_support.py
+++ b/Lib/_aix_support.py
@@ -0,0 +1,108 @@
+"""Shared AIX support functions."""
+
+import sys
+import sysconfig
+
+
+# Taken from _osx_support _read_output function
+def _read_cmd_output(commandstring, capture_stderr=False):
+    """Output from successful command execution or None"""
+    # Similar to os.popen(commandstring, "r").read(),
+    # but without actually using os.popen because that
+    # function is not usable during python bootstrap.
+    import os
+    import contextlib
+    fp = open("/tmp/_aix_support.%s"%(
+        os.getpid(),), "w+b")
+
+    with contextlib.closing(fp) as fp:
+        if capture_stderr:
+            cmd = "%s >'%s' 2>&1" % (commandstring, fp.name)
+        else:
+            cmd = "%s 2>/dev/null >'%s'" % (commandstring, fp.name)
+        return fp.read() if not os.system(cmd) else None
+
+
+def _aix_tag(vrtl, bd):
+    # type: (List[int], int) -> str
+    # Infer the ABI bitwidth from maxsize (assuming 64 bit as the default)
+    _sz = 32 if sys.maxsize == (2**31-1) else 64
+    _bd = bd if bd != 0 else 9988
+    # vrtl[version, release, technology_level]
+    return "aix-{:1x}{:1d}{:02d}-{:04d}-{}".format(vrtl[0], vrtl[1], vrtl[2], _bd, _sz)
+
+
+# extract version, release and technology level from a VRMF string
+def _aix_vrtl(vrmf):
+    # type: (str) -> List[int]
+    v, r, tl = vrmf.split(".")[:3]
+    return [int(v[-1]), int(r), int(tl)]
+
+
+def _aix_bos_rte():
+    # type: () -> Tuple[str, int]
+    """
+    Return a Tuple[str, int] e.g., ['7.1.4.34', 1806]
+    The fileset bos.rte represents the current AIX run-time level. It's VRMF and
+    builddate reflect the current ABI levels of the runtime environment.
+    If no builddate is found give a value that will satisfy pep425 related queries
+    """
+    # All AIX systems to have lslpp installed in this location
+    # subprocess may not be available during python bootstrap
+    try:
+        import subprocess
+        out = subprocess.check_output(["/usr/bin/lslpp", "-Lqc", "bos.rte"])
+    except ImportError:
+        out = _read_cmd_output("/usr/bin/lslpp -Lqc bos.rte")
+    out = out.decode("utf-8")
+    out = out.strip().split(":")  # type: ignore
+    _bd = int(out[-1]) if out[-1] != '' else 9988
+    return (str(out[2]), _bd)
+
+
+def aix_platform():
+    # type: () -> str
+    """
+    AIX filesets are identified by four decimal values: V.R.M.F.
+    V (version) and R (release) can be retrieved using ``uname``
+    Since 2007, starting with AIX 5.3 TL7, the M value has been
+    included with the fileset bos.rte and represents the Technology
+    Level (TL) of AIX. The F (Fix) value also increases, but is not
+    relevant for comparing releases and binary compatibility.
+    For binary compatibility the so-called builddate is needed.
+    Again, the builddate of an AIX release is associated with bos.rte.
+    AIX ABI compatibility is described  as guaranteed at: https://www.ibm.com/\
+    support/knowledgecenter/en/ssw_aix_72/install/binary_compatability.html
+
+    For pep425 purposes the AIX platform tag becomes:
+    "aix-{:1x}{:1d}{:02d}-{:04d}-{}".format(v, r, tl, builddate, bitsize)
+    e.g., "aix-6107-1415-32" for AIX 6.1 TL7 bd 1415, 32-bit
+    and, "aix-6107-1415-64" for AIX 6.1 TL7 bd 1415, 64-bit
+    """
+    vrmf, bd = _aix_bos_rte()
+    return _aix_tag(_aix_vrtl(vrmf), bd)
+
+
+# extract vrtl from the BUILD_GNU_TYPE as an int
+def _aix_bgt():
+    # type: () -> List[int]
+    gnu_type = sysconfig.get_config_var("BUILD_GNU_TYPE")
+    if not gnu_type:
+        raise ValueError("BUILD_GNU_TYPE is not defined")
+    return _aix_vrtl(vrmf=gnu_type)
+
+
+def aix_buildtag():
+    # type: () -> str
+    """
+    Return the platform_tag of the system Python was built on.
+    """
+    # AIX_BUILDDATE is defined by configure with:
+    # lslpp -Lcq bos.rte | awk -F:  '{ print $NF }'
+    build_date = sysconfig.get_config_var("AIX_BUILDDATE")
+    try:
+        build_date = int(build_date)
+    except (ValueError, TypeError):
+        raise ValueError(f"AIX_BUILDDATE is not defined or invalid: "
+                         f"{build_date!r}")
+    return _aix_tag(_aix_bgt(), build_date)
--- a/Lib/_android_support.py
+++ b/Lib/_android_support.py
@@ -0,0 +1,181 @@
+import io
+import sys
+from threading import RLock
+from time import sleep, time
+
+# The maximum length of a log message in bytes, including the level marker and
+# tag, is defined as LOGGER_ENTRY_MAX_PAYLOAD at
+# https://cs.android.com/android/platform/superproject/+/android-14.0.0_r1:system/logging/liblog/include/log/log.h;l=71.
+# Messages longer than this will be truncated by logcat. This limit has already
+# been reduced at least once in the history of Android (from 4076 to 4068 between
+# API level 23 and 26), so leave some headroom.
+MAX_BYTES_PER_WRITE = 4000
+
+# UTF-8 uses a maximum of 4 bytes per character, so limiting text writes to this
+# size ensures that we can always avoid exceeding MAX_BYTES_PER_WRITE.
+# However, if the actual number of bytes per character is smaller than that,
+# then we may still join multiple consecutive text writes into binary
+# writes containing a larger number of characters.
+MAX_CHARS_PER_WRITE = MAX_BYTES_PER_WRITE // 4
+
+
+# When embedded in an app on current versions of Android, there's no easy way to
+# monitor the C-level stdout and stderr. The testbed comes with a .c file to
+# redirect them to the system log using a pipe, but that wouldn't be convenient
+# or appropriate for all apps. So we redirect at the Python level instead.
+def init_streams(android_log_write, stdout_prio, stderr_prio):
+    if sys.executable:
+        return  # Not embedded in an app.
+
+    global logcat
+    logcat = Logcat(android_log_write)
+
+    sys.stdout = TextLogStream(
+        stdout_prio, "python.stdout", sys.stdout.fileno())
+    sys.stderr = TextLogStream(
+        stderr_prio, "python.stderr", sys.stderr.fileno())
+
+
+class TextLogStream(io.TextIOWrapper):
+    def __init__(self, prio, tag, fileno=None, **kwargs):
+        # The default is surrogateescape for stdout and backslashreplace for
+        # stderr, but in the context of an Android log, readability is more
+        # important than reversibility.
+        kwargs.setdefault("encoding", "UTF-8")
+        kwargs.setdefault("errors", "backslashreplace")
+
+        super().__init__(BinaryLogStream(prio, tag, fileno), **kwargs)
+        self._lock = RLock()
+        self._pending_bytes = []
+        self._pending_bytes_count = 0
+
+    def __repr__(self):
+        return f"<TextLogStream {self.buffer.tag!r}>"
+
+    def write(self, s):
+        if not isinstance(s, str):
+            raise TypeError(
+                f"write() argument must be str, not {type(s).__name__}")
+
+        # In case `s` is a str subclass that writes itself to stdout or stderr
+        # when we call its methods, convert it to an actual str.
+        s = str.__str__(s)
+
+        # We want to emit one log message per line wherever possible, so split
+        # the string into lines first. Note that "".splitlines() == [], so
+        # nothing will be logged for an empty string.
+        with self._lock:
+            for line in s.splitlines(keepends=True):
+                while line:
+                    chunk = line[:MAX_CHARS_PER_WRITE]
+                    line = line[MAX_CHARS_PER_WRITE:]
+                    self._write_chunk(chunk)
+
+        return len(s)
+
+    # The size and behavior of TextIOWrapper's buffer is not part of its public
+    # API, so we handle buffering ourselves to avoid truncation.
+    def _write_chunk(self, s):
+        b = s.encode(self.encoding, self.errors)
+        if self._pending_bytes_count + len(b) > MAX_BYTES_PER_WRITE:
+            self.flush()
+
+        self._pending_bytes.append(b)
+        self._pending_bytes_count += len(b)
+        if (
+            self.write_through
+            or b.endswith(b"\n")
+            or self._pending_bytes_count > MAX_BYTES_PER_WRITE
+        ):
+            self.flush()
+
+    def flush(self):
+        with self._lock:
+            self.buffer.write(b"".join(self._pending_bytes))
+            self._pending_bytes.clear()
+            self._pending_bytes_count = 0
+
+    # Since this is a line-based logging system, line buffering cannot be turned
+    # off, i.e. a newline always causes a flush.
+    @property
+    def line_buffering(self):
+        return True
+
+
+class BinaryLogStream(io.RawIOBase):
+    def __init__(self, prio, tag, fileno=None):
+        self.prio = prio
+        self.tag = tag
+        self._fileno = fileno
+
+    def __repr__(self):
+        return f"<BinaryLogStream {self.tag!r}>"
+
+    def writable(self):
+        return True
+
+    def write(self, b):
+        if type(b) is not bytes:
+            try:
+                b = bytes(memoryview(b))
+            except TypeError:
+                raise TypeError(
+                    f"write() argument must be bytes-like, not {type(b).__name__}"
+                ) from None
+
+        # Writing an empty string to the stream should have no effect.
+        if b:
+            logcat.write(self.prio, self.tag, b)
+        return len(b)
+
+    # This is needed by the test suite --timeout option, which uses faulthandler.
+    def fileno(self):
+        if self._fileno is None:
+            raise io.UnsupportedOperation("fileno")
+        return self._fileno
+
+
+# When a large volume of data is written to logcat at once, e.g. when a test
+# module fails in --verbose3 mode, there's a risk of overflowing logcat's own
+# buffer and losing messages. We avoid this by imposing a rate limit using the
+# token bucket algorithm, based on a conservative estimate of how fast `adb
+# logcat` can consume data.
+MAX_BYTES_PER_SECOND = 1024 * 1024
+
+# The logcat buffer size of a device can be determined by running `logcat -g`.
+# We set the token bucket size to half of the buffer size of our current minimum
+# API level, because other things on the system will be producing messages as
+# well.
+BUCKET_SIZE = 128 * 1024
+
+# https://cs.android.com/android/platform/superproject/+/android-14.0.0_r1:system/logging/liblog/include/log/log_read.h;l=39
+PER_MESSAGE_OVERHEAD = 28
+
+
+class Logcat:
+    def __init__(self, android_log_write):
+        self.android_log_write = android_log_write
+        self._lock = RLock()
+        self._bucket_level = 0
+        self._prev_write_time = time()
+
+    def write(self, prio, tag, message):
+        # Encode null bytes using "modified UTF-8" to avoid them truncating the
+        # message.
+        message = message.replace(b"\x00", b"\xc0\x80")
+
+        with self._lock:
+            now = time()
+            self._bucket_level += (
+                (now - self._prev_write_time) * MAX_BYTES_PER_SECOND)
+
+            # If the bucket level is still below zero, the clock must have gone
+            # backwards, so reset it to zero and continue.
+            self._bucket_level = max(0, min(self._bucket_level, BUCKET_SIZE))
+            self._prev_write_time = now
+
+            self._bucket_level -= PER_MESSAGE_OVERHEAD + len(tag) + len(message)
+            if self._bucket_level < 0:
+                sleep(-self._bucket_level / MAX_BYTES_PER_SECOND)
+
+            self.android_log_write(prio, tag, message)
--- a/Lib/_apple_support.py
+++ b/Lib/_apple_support.py
@@ -0,0 +1,66 @@
+import io
+import sys
+
+
+def init_streams(log_write, stdout_level, stderr_level):
+    # Redirect stdout and stderr to the Apple system log. This method is
+    # invoked by init_apple_streams() (initconfig.c) if config->use_system_logger
+    # is enabled.
+    sys.stdout = SystemLog(log_write, stdout_level, errors=sys.stderr.errors)
+    sys.stderr = SystemLog(log_write, stderr_level, errors=sys.stderr.errors)
+
+
+class SystemLog(io.TextIOWrapper):
+    def __init__(self, log_write, level, **kwargs):
+        kwargs.setdefault("encoding", "UTF-8")
+        kwargs.setdefault("line_buffering", True)
+        super().__init__(LogStream(log_write, level), **kwargs)
+
+    def __repr__(self):
+        return f"<SystemLog (level {self.buffer.level})>"
+
+    def write(self, s):
+        if not isinstance(s, str):
+            raise TypeError(
+                f"write() argument must be str, not {type(s).__name__}")
+
+        # In case `s` is a str subclass that writes itself to stdout or stderr
+        # when we call its methods, convert it to an actual str.
+        s = str.__str__(s)
+
+        # We want to emit one log message per line, so split
+        # the string before sending it to the superclass.
+        for line in s.splitlines(keepends=True):
+            super().write(line)
+
+        return len(s)
+
+
+class LogStream(io.RawIOBase):
+    def __init__(self, log_write, level):
+        self.log_write = log_write
+        self.level = level
+
+    def __repr__(self):
+        return f"<LogStream (level {self.level!r})>"
+
+    def writable(self):
+        return True
+
+    def write(self, b):
+        if type(b) is not bytes:
+            try:
+                b = bytes(memoryview(b))
+            except TypeError:
+                raise TypeError(
+                    f"write() argument must be bytes-like, not {type(b).__name__}"
+                ) from None
+
+        # Writing an empty string to the stream should have no effect.
+        if b:
+            # Encode null bytes using "modified UTF-8" to avoid truncating the
+            # message. This should not affect the return value, as the caller
+            # may be expecting it to match the length of the input.
+            self.log_write(self.level, b.replace(b"\x00", b"\xc0\x80"))
+
+        return len(b)
--- a/Lib/_collections_abc.py
+++ b/Lib/_collections_abc.py
@@ -6,6 +6,32 @@
 Unit tests are in test_collections.
 """

+############ Maintenance notes #########################################
+#
+# ABCs are different from other standard library modules in that they
+# specify compliance tests.  In general, once an ABC has been published,
+# new methods (either abstract or concrete) cannot be added.
+#
+# Though classes that inherit from an ABC would automatically receive a
+# new mixin method, registered classes would become non-compliant and
+# violate the contract promised by ``isinstance(someobj, SomeABC)``.
+#
+# Though irritating, the correct procedure for adding new abstract or
+# mixin methods is to create a new ABC as a subclass of the previous
+# ABC.  For example, union(), intersection(), and difference() cannot
+# be added to Set but could go into a new ABC that extends Set.
+#
+# Because they are so hard to change, new ABCs should have their APIs
+# carefully thought through prior to publication.
+#
+# Since ABCMeta only checks for the presence of methods, it is possible
+# to alter the signature of a method by adding optional arguments
+# or changing parameters names.  This is still a bit dubious but at
+# least it won't cause isinstance() to return an incorrect result.
+#
+#
+#######################################################################
+
 from abc import ABCMeta, abstractmethod
 import sys

@@ -23,7 +49,7 @@ __all__ = ["Awaitable", "Coroutine",
           "Mapping", "MutableMapping",
           "MappingView", "KeysView", "ItemsView", "ValuesView",
           "Sequence", "MutableSequence",
-           "ByteString",
+           "ByteString", "Buffer",
           ]

 # This module has been renamed from collections.abc to _collections_abc to
@@ -59,6 +85,10 @@ dict_values = type({}.values())
 dict_items = type({}.items())
 ## misc ##
 mappingproxy = type(type.__dict__)
+def _get_framelocalsproxy():
+    return type(sys._getframe().f_locals)
+framelocalsproxy = _get_framelocalsproxy()
+del _get_framelocalsproxy
 generator = type((lambda: (yield))())
 ## coroutine ##
 async def _coro(): pass
@@ -413,6 +443,21 @@ class Collection(Sized, Iterable, Container):
        return NotImplemented


+class Buffer(metaclass=ABCMeta):
+
+    __slots__ = ()
+
+    @abstractmethod
+    def __buffer__(self, flags: int, /) -> memoryview:
+        raise NotImplementedError
+
+    @classmethod
+    def __subclasshook__(cls, C):
+        if cls is Buffer:
+            return _check_methods(C, "__buffer__")
+        return NotImplemented
+
+
 class _CallableGenericAlias(GenericAlias):
    """ Represent `Callable[argtypes, resulttype]`.

@@ -455,15 +500,8 @@ class _CallableGenericAlias(GenericAlias):
        # rather than the default types.GenericAlias object.  Most of the
        # code is copied from typing's _GenericAlias and the builtin
        # types.GenericAlias.
-
        if not isinstance(item, tuple):
            item = (item,)
-        # A special case in PEP 612 where if X = Callable[P, int],
-        # then X[int, str] == X[[int, str]].
-        if (len(self.__parameters__) == 1
-                and _is_param_expr(self.__parameters__[0])
-                and item and not _is_param_expr(item[0])):
-            item = (item,)

        new_args = super().__getitem__(item).__args__

@@ -474,6 +512,10 @@ class _CallableGenericAlias(GenericAlias):
            new_args = (t_args, t_result)
        return _CallableGenericAlias(Callable, tuple(new_args))

+    # TODO: RUSTPYTHON patch for common call
+    def __or__(self, other):
+        super().__or__(other)
+
 def _is_param_expr(obj):
    """Checks if obj matches either a list of types, ``...``, ``ParamSpec`` or
    ``_ConcatenateGenericAlias`` from typing.py
@@ -491,9 +533,8 @@ def _type_repr(obj):

    Copied from :mod:`typing` since collections.abc
    shouldn't depend on that module.
+    (Keep this roughly in sync with the typing version.)
    """
-    if isinstance(obj, GenericAlias):
-        return repr(obj)
    if isinstance(obj, type):
        if obj.__module__ == 'builtins':
            return obj.__qualname__
@@ -803,6 +844,7 @@ class Mapping(Collection):
    __reversed__ = None

 Mapping.register(mappingproxy)
+Mapping.register(framelocalsproxy)


 class MappingView(Sized):
@@ -940,7 +982,7 @@ class MutableMapping(Mapping):

    def update(self, other=(), /, **kwds):
        ''' D.update([E, ]**F) -> None.  Update D from mapping/iterable E and F.
-            If E present and has a .keys() method, does:     for k in E: D[k] = E[k]
+            If E present and has a .keys() method, does:     for k in E.keys(): D[k] = E[k]
            If E present and lacks .keys() method, does:     for (k, v) in E: D[k] = v
            In either case, this is followed by: for k, v in F.items(): D[k] = v
        '''
@@ -1038,8 +1080,27 @@ Sequence.register(str)
 Sequence.register(range)
 Sequence.register(memoryview)

+class _DeprecateByteStringMeta(ABCMeta):
+    def __new__(cls, name, bases, namespace, **kwargs):
+        if name != "ByteString":
+            import warnings

-class ByteString(Sequence):
+            warnings._deprecated(
+                "collections.abc.ByteString",
+                remove=(3, 14),
+            )
+        return super().__new__(cls, name, bases, namespace, **kwargs)
+
+    def __instancecheck__(cls, instance):
+        import warnings
+
+        warnings._deprecated(
+            "collections.abc.ByteString",
+            remove=(3, 14),
+        )
+        return super().__instancecheck__(instance)
+
+class ByteString(Sequence, metaclass=_DeprecateByteStringMeta):
    """This unifies bytes and bytearray.

    XXX Should add all their methods.
--- a/Lib/_colorize.py
+++ b/Lib/_colorize.py
@@ -0,0 +1,112 @@
+from __future__ import annotations
+import io
+import os
+import sys
+
+COLORIZE = True
+
+# types
+if False:
+    from typing import IO
+
+
+class ANSIColors:
+    RESET = "\x1b[0m"
+
+    BLACK = "\x1b[30m"
+    BLUE = "\x1b[34m"
+    CYAN = "\x1b[36m"
+    GREEN = "\x1b[32m"
+    MAGENTA = "\x1b[35m"
+    RED = "\x1b[31m"
+    WHITE = "\x1b[37m"  # more like LIGHT GRAY
+    YELLOW = "\x1b[33m"
+
+    BOLD_BLACK = "\x1b[1;30m"  # DARK GRAY
+    BOLD_BLUE = "\x1b[1;34m"
+    BOLD_CYAN = "\x1b[1;36m"
+    BOLD_GREEN = "\x1b[1;32m"
+    BOLD_MAGENTA = "\x1b[1;35m"
+    BOLD_RED = "\x1b[1;31m"
+    BOLD_WHITE = "\x1b[1;37m"  # actual WHITE
+    BOLD_YELLOW = "\x1b[1;33m"
+
+    # intense = like bold but without being bold
+    INTENSE_BLACK = "\x1b[90m"
+    INTENSE_BLUE = "\x1b[94m"
+    INTENSE_CYAN = "\x1b[96m"
+    INTENSE_GREEN = "\x1b[92m"
+    INTENSE_MAGENTA = "\x1b[95m"
+    INTENSE_RED = "\x1b[91m"
+    INTENSE_WHITE = "\x1b[97m"
+    INTENSE_YELLOW = "\x1b[93m"
+
+    BACKGROUND_BLACK = "\x1b[40m"
+    BACKGROUND_BLUE = "\x1b[44m"
+    BACKGROUND_CYAN = "\x1b[46m"
+    BACKGROUND_GREEN = "\x1b[42m"
+    BACKGROUND_MAGENTA = "\x1b[45m"
+    BACKGROUND_RED = "\x1b[41m"
+    BACKGROUND_WHITE = "\x1b[47m"
+    BACKGROUND_YELLOW = "\x1b[43m"
+
+    INTENSE_BACKGROUND_BLACK = "\x1b[100m"
+    INTENSE_BACKGROUND_BLUE = "\x1b[104m"
+    INTENSE_BACKGROUND_CYAN = "\x1b[106m"
+    INTENSE_BACKGROUND_GREEN = "\x1b[102m"
+    INTENSE_BACKGROUND_MAGENTA = "\x1b[105m"
+    INTENSE_BACKGROUND_RED = "\x1b[101m"
+    INTENSE_BACKGROUND_WHITE = "\x1b[107m"
+    INTENSE_BACKGROUND_YELLOW = "\x1b[103m"
+
+
+NoColors = ANSIColors()
+
+for attr in dir(NoColors):
+    if not attr.startswith("__"):
+        setattr(NoColors, attr, "")
+
+
+def get_colors(
+    colorize: bool = False, *, file: IO[str] | IO[bytes] | None = None
+) -> ANSIColors:
+    if colorize or can_colorize(file=file):
+        return ANSIColors()
+    else:
+        return NoColors
+
+
+def can_colorize(*, file: IO[str] | IO[bytes] | None = None) -> bool:
+    if file is None:
+        file = sys.stdout
+
+    if not sys.flags.ignore_environment:
+        if os.environ.get("PYTHON_COLORS") == "0":
+            return False
+        if os.environ.get("PYTHON_COLORS") == "1":
+            return True
+    if os.environ.get("NO_COLOR"):
+        return False
+    if not COLORIZE:
+        return False
+    if os.environ.get("FORCE_COLOR"):
+        return True
+    if os.environ.get("TERM") == "dumb":
+        return False
+
+    if not hasattr(file, "fileno"):
+        return False
+
+    if sys.platform == "win32":
+        try:
+            import nt
+
+            if not nt._supports_virtual_terminal():
+                return False
+        except (ImportError, AttributeError):
+            return False
+
+    try:
+        return os.isatty(file.fileno())
+    except io.UnsupportedOperation:
+        return hasattr(file, "isatty") and file.isatty()
--- a/Lib/_dummy_os.py
+++ b/Lib/_dummy_os.py
@@ -5,22 +5,30 @@ A shim of the os module containing only simple path-related utilities
 try:
    from os import *
 except ImportError:
-    import abc
+    import abc, sys

    def __getattr__(name):
-        raise OSError("no os specific module found")
+        if name in {"_path_normpath", "__path__"}:
+            raise AttributeError(name)
+        if name.isupper():
+            return 0
+        def dummy(*args, **kwargs):
+            import io
+            return io.UnsupportedOperation(f"{name}: no os specific module found")
+        dummy.__name__ = f"dummy_{name}"
+        return dummy

-    def _shim():
-        import _dummy_os, sys
-        sys.modules['os'] = _dummy_os
-        sys.modules['os.path'] = _dummy_os.path
+    sys.modules['os'] = sys.modules['posix'] = sys.modules[__name__]

    import posixpath as path
-    import sys
    sys.modules['os.path'] = path
    del sys

    sep = path.sep
+    supports_dir_fd = set()
+    supports_effective_ids = set()
+    supports_fd = set()
+    supports_follow_symlinks = set()


    def fspath(path):
--- a/Lib/_ios_support.py
+++ b/Lib/_ios_support.py
@@ -0,0 +1,71 @@
+import sys
+try:
+    from ctypes import cdll, c_void_p, c_char_p, util
+except ImportError:
+    # ctypes is an optional module. If it's not present, we're limited in what
+    # we can tell about the system, but we don't want to prevent the module
+    # from working.
+    print("ctypes isn't available; iOS system calls will not be available", file=sys.stderr)
+    objc = None
+else:
+    # ctypes is available. Load the ObjC library, and wrap the objc_getClass,
+    # sel_registerName methods
+    lib = util.find_library("objc")
+    if lib is None:
+        # Failed to load the objc library
+        raise ImportError("ObjC runtime library couldn't be loaded")
+
+    objc = cdll.LoadLibrary(lib)
+    objc.objc_getClass.restype = c_void_p
+    objc.objc_getClass.argtypes = [c_char_p]
+    objc.sel_registerName.restype = c_void_p
+    objc.sel_registerName.argtypes = [c_char_p]
+
+
+def get_platform_ios():
+    # Determine if this is a simulator using the multiarch value
+    is_simulator = sys.implementation._multiarch.endswith("simulator")
+
+    # We can't use ctypes; abort
+    if not objc:
+        return None
+
+    # Most of the methods return ObjC objects
+    objc.objc_msgSend.restype = c_void_p
+    # All the methods used have no arguments.
+    objc.objc_msgSend.argtypes = [c_void_p, c_void_p]
+
+    # Equivalent of:
+    #   device = [UIDevice currentDevice]
+    UIDevice = objc.objc_getClass(b"UIDevice")
+    SEL_currentDevice = objc.sel_registerName(b"currentDevice")
+    device = objc.objc_msgSend(UIDevice, SEL_currentDevice)
+
+    # Equivalent of:
+    #   device_systemVersion = [device systemVersion]
+    SEL_systemVersion = objc.sel_registerName(b"systemVersion")
+    device_systemVersion = objc.objc_msgSend(device, SEL_systemVersion)
+
+    # Equivalent of:
+    #   device_systemName = [device systemName]
+    SEL_systemName = objc.sel_registerName(b"systemName")
+    device_systemName = objc.objc_msgSend(device, SEL_systemName)
+
+    # Equivalent of:
+    #   device_model = [device model]
+    SEL_model = objc.sel_registerName(b"model")
+    device_model = objc.objc_msgSend(device, SEL_model)
+
+    # UTF8String returns a const char*;
+    SEL_UTF8String = objc.sel_registerName(b"UTF8String")
+    objc.objc_msgSend.restype = c_char_p
+
+    # Equivalent of:
+    #   system = [device_systemName UTF8String]
+    #   release = [device_systemVersion UTF8String]
+    #   model = [device_model UTF8String]
+    system = objc.objc_msgSend(device_systemName, SEL_UTF8String).decode()
+    release = objc.objc_msgSend(device_systemVersion, SEL_UTF8String).decode()
+    model = objc.objc_msgSend(device_model, SEL_UTF8String).decode()
+
+    return system, release, model, is_simulator
--- a/Lib/_opcode_metadata.py
+++ b/Lib/_opcode_metadata.py
@@ -0,0 +1,343 @@
+# This file is generated by Tools/cases_generator/py_metadata_generator.py
+# from:
+#   Python/bytecodes.c
+# Do not edit!
+_specializations = {
+    "RESUME": [
+        "RESUME_CHECK",
+    ],
+    "TO_BOOL": [
+        "TO_BOOL_ALWAYS_TRUE",
+        "TO_BOOL_BOOL",
+        "TO_BOOL_INT",
+        "TO_BOOL_LIST",
+        "TO_BOOL_NONE",
+        "TO_BOOL_STR",
+    ],
+    "BINARY_OP": [
+        "BINARY_OP_MULTIPLY_INT",
+        "BINARY_OP_ADD_INT",
+        "BINARY_OP_SUBTRACT_INT",
+        "BINARY_OP_MULTIPLY_FLOAT",
+        "BINARY_OP_ADD_FLOAT",
+        "BINARY_OP_SUBTRACT_FLOAT",
+        "BINARY_OP_ADD_UNICODE",
+        "BINARY_OP_INPLACE_ADD_UNICODE",
+    ],
+    "BINARY_SUBSCR": [
+        "BINARY_SUBSCR_DICT",
+        "BINARY_SUBSCR_GETITEM",
+        "BINARY_SUBSCR_LIST_INT",
+        "BINARY_SUBSCR_STR_INT",
+        "BINARY_SUBSCR_TUPLE_INT",
+    ],
+    "STORE_SUBSCR": [
+        "STORE_SUBSCR_DICT",
+        "STORE_SUBSCR_LIST_INT",
+    ],
+    "SEND": [
+        "SEND_GEN",
+    ],
+    "UNPACK_SEQUENCE": [
+        "UNPACK_SEQUENCE_TWO_TUPLE",
+        "UNPACK_SEQUENCE_TUPLE",
+        "UNPACK_SEQUENCE_LIST",
+    ],
+    "STORE_ATTR": [
+        "STORE_ATTR_INSTANCE_VALUE",
+        "STORE_ATTR_SLOT",
+        "STORE_ATTR_WITH_HINT",
+    ],
+    "LOAD_GLOBAL": [
+        "LOAD_GLOBAL_MODULE",
+        "LOAD_GLOBAL_BUILTIN",
+    ],
+    "LOAD_SUPER_ATTR": [
+        "LOAD_SUPER_ATTR_ATTR",
+        "LOAD_SUPER_ATTR_METHOD",
+    ],
+    "LOAD_ATTR": [
+        "LOAD_ATTR_INSTANCE_VALUE",
+        "LOAD_ATTR_MODULE",
+        "LOAD_ATTR_WITH_HINT",
+        "LOAD_ATTR_SLOT",
+        "LOAD_ATTR_CLASS",
+        "LOAD_ATTR_PROPERTY",
+        "LOAD_ATTR_GETATTRIBUTE_OVERRIDDEN",
+        "LOAD_ATTR_METHOD_WITH_VALUES",
+        "LOAD_ATTR_METHOD_NO_DICT",
+        "LOAD_ATTR_METHOD_LAZY_DICT",
+        "LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES",
+        "LOAD_ATTR_NONDESCRIPTOR_NO_DICT",
+    ],
+    "COMPARE_OP": [
+        "COMPARE_OP_FLOAT",
+        "COMPARE_OP_INT",
+        "COMPARE_OP_STR",
+    ],
+    "CONTAINS_OP": [
+        "CONTAINS_OP_SET",
+        "CONTAINS_OP_DICT",
+    ],
+    "FOR_ITER": [
+        "FOR_ITER_LIST",
+        "FOR_ITER_TUPLE",
+        "FOR_ITER_RANGE",
+        "FOR_ITER_GEN",
+    ],
+    "CALL": [
+        "CALL_BOUND_METHOD_EXACT_ARGS",
+        "CALL_PY_EXACT_ARGS",
+        "CALL_TYPE_1",
+        "CALL_STR_1",
+        "CALL_TUPLE_1",
+        "CALL_BUILTIN_CLASS",
+        "CALL_BUILTIN_O",
+        "CALL_BUILTIN_FAST",
+        "CALL_BUILTIN_FAST_WITH_KEYWORDS",
+        "CALL_LEN",
+        "CALL_ISINSTANCE",
+        "CALL_LIST_APPEND",
+        "CALL_METHOD_DESCRIPTOR_O",
+        "CALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS",
+        "CALL_METHOD_DESCRIPTOR_NOARGS",
+        "CALL_METHOD_DESCRIPTOR_FAST",
+        "CALL_ALLOC_AND_ENTER_INIT",
+        "CALL_PY_GENERAL",
+        "CALL_BOUND_METHOD_GENERAL",
+        "CALL_NON_PY_GENERAL",
+    ],
+}
+
+_specialized_opmap = {
+    'BINARY_OP_ADD_FLOAT': 150,
+    'BINARY_OP_ADD_INT': 151,
+    'BINARY_OP_ADD_UNICODE': 152,
+    'BINARY_OP_INPLACE_ADD_UNICODE': 3,
+    'BINARY_OP_MULTIPLY_FLOAT': 153,
+    'BINARY_OP_MULTIPLY_INT': 154,
+    'BINARY_OP_SUBTRACT_FLOAT': 155,
+    'BINARY_OP_SUBTRACT_INT': 156,
+    'BINARY_SUBSCR_DICT': 157,
+    'BINARY_SUBSCR_GETITEM': 158,
+    'BINARY_SUBSCR_LIST_INT': 159,
+    'BINARY_SUBSCR_STR_INT': 160,
+    'BINARY_SUBSCR_TUPLE_INT': 161,
+    'CALL_ALLOC_AND_ENTER_INIT': 162,
+    'CALL_BOUND_METHOD_EXACT_ARGS': 163,
+    'CALL_BOUND_METHOD_GENERAL': 164,
+    'CALL_BUILTIN_CLASS': 165,
+    'CALL_BUILTIN_FAST': 166,
+    'CALL_BUILTIN_FAST_WITH_KEYWORDS': 167,
+    'CALL_BUILTIN_O': 168,
+    'CALL_ISINSTANCE': 169,
+    'CALL_LEN': 170,
+    'CALL_LIST_APPEND': 171,
+    'CALL_METHOD_DESCRIPTOR_FAST': 172,
+    'CALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS': 173,
+    'CALL_METHOD_DESCRIPTOR_NOARGS': 174,
+    'CALL_METHOD_DESCRIPTOR_O': 175,
+    'CALL_NON_PY_GENERAL': 176,
+    'CALL_PY_EXACT_ARGS': 177,
+    'CALL_PY_GENERAL': 178,
+    'CALL_STR_1': 179,
+    'CALL_TUPLE_1': 180,
+    'CALL_TYPE_1': 181,
+    'COMPARE_OP_FLOAT': 182,
+    'COMPARE_OP_INT': 183,
+    'COMPARE_OP_STR': 184,
+    'CONTAINS_OP_DICT': 185,
+    'CONTAINS_OP_SET': 186,
+    'FOR_ITER_GEN': 187,
+    'FOR_ITER_LIST': 188,
+    'FOR_ITER_RANGE': 189,
+    'FOR_ITER_TUPLE': 190,
+    'LOAD_ATTR_CLASS': 191,
+    'LOAD_ATTR_GETATTRIBUTE_OVERRIDDEN': 192,
+    'LOAD_ATTR_INSTANCE_VALUE': 193,
+    'LOAD_ATTR_METHOD_LAZY_DICT': 194,
+    'LOAD_ATTR_METHOD_NO_DICT': 195,
+    'LOAD_ATTR_METHOD_WITH_VALUES': 196,
+    'LOAD_ATTR_MODULE': 197,
+    'LOAD_ATTR_NONDESCRIPTOR_NO_DICT': 198,
+    'LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES': 199,
+    'LOAD_ATTR_PROPERTY': 200,
+    'LOAD_ATTR_SLOT': 201,
+    'LOAD_ATTR_WITH_HINT': 202,
+    'LOAD_GLOBAL_BUILTIN': 203,
+    'LOAD_GLOBAL_MODULE': 204,
+    'LOAD_SUPER_ATTR_ATTR': 205,
+    'LOAD_SUPER_ATTR_METHOD': 206,
+    'RESUME_CHECK': 207,
+    'SEND_GEN': 208,
+    'STORE_ATTR_INSTANCE_VALUE': 209,
+    'STORE_ATTR_SLOT': 210,
+    'STORE_ATTR_WITH_HINT': 211,
+    'STORE_SUBSCR_DICT': 212,
+    'STORE_SUBSCR_LIST_INT': 213,
+    'TO_BOOL_ALWAYS_TRUE': 214,
+    'TO_BOOL_BOOL': 215,
+    'TO_BOOL_INT': 216,
+    'TO_BOOL_LIST': 217,
+    'TO_BOOL_NONE': 218,
+    'TO_BOOL_STR': 219,
+    'UNPACK_SEQUENCE_LIST': 220,
+    'UNPACK_SEQUENCE_TUPLE': 221,
+    'UNPACK_SEQUENCE_TWO_TUPLE': 222,
+}
+
+opmap = {
+    'CACHE': 0,
+    'RESERVED': 17,
+    'RESUME': 149,
+    'INSTRUMENTED_LINE': 254,
+    'BEFORE_ASYNC_WITH': 1,
+    'BEFORE_WITH': 2,
+    'BINARY_SLICE': 4,
+    'BINARY_SUBSCR': 5,
+    'CHECK_EG_MATCH': 6,
+    'CHECK_EXC_MATCH': 7,
+    'CLEANUP_THROW': 8,
+    'DELETE_SUBSCR': 9,
+    'END_ASYNC_FOR': 10,
+    'END_FOR': 11,
+    'END_SEND': 12,
+    'EXIT_INIT_CHECK': 13,
+    'FORMAT_SIMPLE': 14,
+    'FORMAT_WITH_SPEC': 15,
+    'GET_AITER': 16,
+    'GET_ANEXT': 18,
+    'GET_ITER': 19,
+    'GET_LEN': 20,
+    'GET_YIELD_FROM_ITER': 21,
+    'INTERPRETER_EXIT': 22,
+    'LOAD_ASSERTION_ERROR': 23,
+    'LOAD_BUILD_CLASS': 24,
+    'LOAD_LOCALS': 25,
+    'MAKE_FUNCTION': 26,
+    'MATCH_KEYS': 27,
+    'MATCH_MAPPING': 28,
+    'MATCH_SEQUENCE': 29,
+    'NOP': 30,
+    'POP_EXCEPT': 31,
+    'POP_TOP': 32,
+    'PUSH_EXC_INFO': 33,
+    'PUSH_NULL': 34,
+    'RETURN_GENERATOR': 35,
+    'RETURN_VALUE': 36,
+    'SETUP_ANNOTATIONS': 37,
+    'STORE_SLICE': 38,
+    'STORE_SUBSCR': 39,
+    'TO_BOOL': 40,
+    'UNARY_INVERT': 41,
+    'UNARY_NEGATIVE': 42,
+    'UNARY_NOT': 43,
+    'WITH_EXCEPT_START': 44,
+    'BINARY_OP': 45,
+    'BUILD_CONST_KEY_MAP': 46,
+    'BUILD_LIST': 47,
+    'BUILD_MAP': 48,
+    'BUILD_SET': 49,
+    'BUILD_SLICE': 50,
+    'BUILD_STRING': 51,
+    'BUILD_TUPLE': 52,
+    'CALL': 53,
+    'CALL_FUNCTION_EX': 54,
+    'CALL_INTRINSIC_1': 55,
+    'CALL_INTRINSIC_2': 56,
+    'CALL_KW': 57,
+    'COMPARE_OP': 58,
+    'CONTAINS_OP': 59,
+    'CONVERT_VALUE': 60,
+    'COPY': 61,
+    'COPY_FREE_VARS': 62,
+    'DELETE_ATTR': 63,
+    'DELETE_DEREF': 64,
+    'DELETE_FAST': 65,
+    'DELETE_GLOBAL': 66,
+    'DELETE_NAME': 67,
+    'DICT_MERGE': 68,
+    'DICT_UPDATE': 69,
+    'ENTER_EXECUTOR': 70,
+    'EXTENDED_ARG': 71,
+    'FOR_ITER': 72,
+    'GET_AWAITABLE': 73,
+    'IMPORT_FROM': 74,
+    'IMPORT_NAME': 75,
+    'IS_OP': 76,
+    'JUMP_BACKWARD': 77,
+    'JUMP_BACKWARD_NO_INTERRUPT': 78,
+    'JUMP_FORWARD': 79,
+    'LIST_APPEND': 80,
+    'LIST_EXTEND': 81,
+    'LOAD_ATTR': 82,
+    'LOAD_CONST': 83,
+    'LOAD_DEREF': 84,
+    'LOAD_FAST': 85,
+    'LOAD_FAST_AND_CLEAR': 86,
+    'LOAD_FAST_CHECK': 87,
+    'LOAD_FAST_LOAD_FAST': 88,
+    'LOAD_FROM_DICT_OR_DEREF': 89,
+    'LOAD_FROM_DICT_OR_GLOBALS': 90,
+    'LOAD_GLOBAL': 91,
+    'LOAD_NAME': 92,
+    'LOAD_SUPER_ATTR': 93,
+    'MAKE_CELL': 94,
+    'MAP_ADD': 95,
+    'MATCH_CLASS': 96,
+    'POP_JUMP_IF_FALSE': 97,
+    'POP_JUMP_IF_NONE': 98,
+    'POP_JUMP_IF_NOT_NONE': 99,
+    'POP_JUMP_IF_TRUE': 100,
+    'RAISE_VARARGS': 101,
+    'RERAISE': 102,
+    'RETURN_CONST': 103,
+    'SEND': 104,
+    'SET_ADD': 105,
+    'SET_FUNCTION_ATTRIBUTE': 106,
+    'SET_UPDATE': 107,
+    'STORE_ATTR': 108,
+    'STORE_DEREF': 109,
+    'STORE_FAST': 110,
+    'STORE_FAST_LOAD_FAST': 111,
+    'STORE_FAST_STORE_FAST': 112,
+    'STORE_GLOBAL': 113,
+    'STORE_NAME': 114,
+    'SWAP': 115,
+    'UNPACK_EX': 116,
+    'UNPACK_SEQUENCE': 117,
+    'YIELD_VALUE': 118,
+    'INSTRUMENTED_RESUME': 236,
+    'INSTRUMENTED_END_FOR': 237,
+    'INSTRUMENTED_END_SEND': 238,
+    'INSTRUMENTED_RETURN_VALUE': 239,
+    'INSTRUMENTED_RETURN_CONST': 240,
+    'INSTRUMENTED_YIELD_VALUE': 241,
+    'INSTRUMENTED_LOAD_SUPER_ATTR': 242,
+    'INSTRUMENTED_FOR_ITER': 243,
+    'INSTRUMENTED_CALL': 244,
+    'INSTRUMENTED_CALL_KW': 245,
+    'INSTRUMENTED_CALL_FUNCTION_EX': 246,
+    'INSTRUMENTED_INSTRUCTION': 247,
+    'INSTRUMENTED_JUMP_FORWARD': 248,
+    'INSTRUMENTED_JUMP_BACKWARD': 249,
+    'INSTRUMENTED_POP_JUMP_IF_TRUE': 250,
+    'INSTRUMENTED_POP_JUMP_IF_FALSE': 251,
+    'INSTRUMENTED_POP_JUMP_IF_NONE': 252,
+    'INSTRUMENTED_POP_JUMP_IF_NOT_NONE': 253,
+    'JUMP': 256,
+    'JUMP_NO_INTERRUPT': 257,
+    'LOAD_CLOSURE': 258,
+    'LOAD_METHOD': 259,
+    'LOAD_SUPER_METHOD': 260,
+    'LOAD_ZERO_SUPER_ATTR': 261,
+    'LOAD_ZERO_SUPER_METHOD': 262,
+    'POP_BLOCK': 263,
+    'SETUP_CLEANUP': 264,
+    'SETUP_FINALLY': 265,
+    'SETUP_WITH': 266,
+    'STORE_FAST_MAYBE_NULL': 267,
+}
+
+HAVE_ARGUMENT = 44
+MIN_INSTRUMENTED_OPCODE = 236
--- a/Lib/_osx_support.py
+++ b/Lib/_osx_support.py
@@ -507,6 +507,11 @@ def get_platform_osx(_config_vars, osname, release, machine):
    # MACOSX_DEPLOYMENT_TARGET.

    macver = _config_vars.get('MACOSX_DEPLOYMENT_TARGET', '')
+    if macver and '.' not in macver:
+        # Ensure that the version includes at least a major
+        # and minor version, even if MACOSX_DEPLOYMENT_TARGET
+        # is set to a single-label version like "14".
+        macver += '.0'
    macrelease = _get_system_version() or macver
    macver = macver or macrelease

--- a/Lib/_pycodecs.py
+++ b/Lib/_pycodecs.py
@@ -1086,11 +1086,13 @@ def charmapencode_output(c, mapping):
    rep = mapping[c]
    if isinstance(rep, int) or isinstance(rep, int):
        if rep < 256:
-            return rep
+            return [rep]
        else:
            raise TypeError("character mapping must be in range(256)")
    elif isinstance(rep, str):
-        return ord(rep)
+        return [ord(rep)]
+    elif isinstance(rep, bytes):
+        return rep
    elif rep == None:
        raise KeyError("character maps to <undefined>")
    else:
@@ -1113,12 +1115,13 @@ def PyUnicode_EncodeCharmap(p, size, mapping='latin-1', errors='strict'):
        #/* try to encode it */
        try:
            x = charmapencode_output(ord(p[inpos]), mapping)
-            res += [x]
+            res += x
        except KeyError:
            x = unicode_call_errorhandler(errors, "charmap",
            "character maps to <undefined>", p, inpos, inpos+1, False)
            try:
-                res += [charmapencode_output(ord(y), mapping) for y in x[0]]
+                for y in x[0]:
+                    res += charmapencode_output(ord(y), mapping)
            except KeyError:
                raise UnicodeEncodeError("charmap", p, inpos, inpos+1,
                                        "character maps to <undefined>")
--- a/Lib/_pydatetime.py
+++ b/Lib/_pydatetime.py
--- a/Lib/_pydecimal.py
+++ b/Lib/_pydecimal.py
@@ -13,104 +13,7 @@
 # bug) and will be backported.  At this point the spec is stabilizing
 # and the updates are becoming fewer, smaller, and less significant.

-"""
-This is an implementation of decimal floating point arithmetic based on
-the General Decimal Arithmetic Specification:
-
-    http://speleotrove.com/decimal/decarith.html
-
-and IEEE standard 854-1987:
-
-    http://en.wikipedia.org/wiki/IEEE_854-1987
-
-Decimal floating point has finite precision with arbitrarily large bounds.
-
-The purpose of this module is to support arithmetic using familiar
-"schoolhouse" rules and to avoid some of the tricky representation
-issues associated with binary floating point.  The package is especially
-useful for financial applications or for contexts where users have
-expectations that are at odds with binary floating point (for instance,
-in binary floating point, 1.00 % 0.1 gives 0.09999999999999995 instead
-of 0.0; Decimal('1.00') % Decimal('0.1') returns the expected
-Decimal('0.00')).
-
-Here are some examples of using the decimal module:
-
->>> from decimal import *
->>> setcontext(ExtendedContext)
->>> Decimal(0)
-Decimal('0')
->>> Decimal('1')
-Decimal('1')
->>> Decimal('-.0123')
-Decimal('-0.0123')
->>> Decimal(123456)
-Decimal('123456')
->>> Decimal('123.45e12345678')
-Decimal('1.2345E+12345680')
->>> Decimal('1.33') + Decimal('1.27')
-Decimal('2.60')
->>> Decimal('12.34') + Decimal('3.87') - Decimal('18.41')
-Decimal('-2.20')
->>> dig = Decimal(1)
->>> print(dig / Decimal(3))
-0.333333333
->>> getcontext().prec = 18
->>> print(dig / Decimal(3))
-0.333333333333333333
->>> print(dig.sqrt())
-1
->>> print(Decimal(3).sqrt())
-1.73205080756887729
->>> print(Decimal(3) ** 123)
-4.85192780976896427E+58
->>> inf = Decimal(1) / Decimal(0)
->>> print(inf)
-Infinity
->>> neginf = Decimal(-1) / Decimal(0)
->>> print(neginf)
-Infinity
->>> print(neginf + inf)
-NaN
->>> print(neginf * inf)
-Infinity
->>> print(dig / 0)
-Infinity
->>> getcontext().traps[DivisionByZero] = 1
->>> print(dig / 0)
-Traceback (most recent call last):
-  ...
-  ...
-  ...
-decimal.DivisionByZero: x / 0
->>> c = Context()
->>> c.traps[InvalidOperation] = 0
->>> print(c.flags[InvalidOperation])
-0
->>> c.divide(Decimal(0), Decimal(0))
-Decimal('NaN')
->>> c.traps[InvalidOperation] = 1
->>> print(c.flags[InvalidOperation])
-1
->>> c.flags[InvalidOperation] = 0
->>> print(c.flags[InvalidOperation])
-0
->>> print(c.divide(Decimal(0), Decimal(0)))
-Traceback (most recent call last):
-  ...
-  ...
-  ...
-decimal.InvalidOperation: 0 / 0
->>> print(c.flags[InvalidOperation])
-1
->>> c.flags[InvalidOperation] = 0
->>> c.traps[InvalidOperation] = 0
->>> print(c.divide(Decimal(0), Decimal(0)))
-NaN
->>> print(c.flags[InvalidOperation])
-1
->>>
-"""
+"""Python decimal arithmetic module"""

 __all__ = [
    # Two major classes
@@ -140,8 +43,11 @@ __all__ = [
    # Limits for the C version for compatibility
    'MAX_PREC',  'MAX_EMAX', 'MIN_EMIN', 'MIN_ETINY',

-    # C version: compile time choice that enables the thread local context
-    'HAVE_THREADS'
+    # C version: compile time choice that enables the thread local context (deprecated, now always true)
+    'HAVE_THREADS',
+
+    # C version: compile time choice that enables the coroutine local context
+    'HAVE_CONTEXTVAR'
 ]

 __xname__ = __name__    # sys.modules lookup (--without-threads)
@@ -156,7 +62,7 @@ import sys

 try:
    from collections import namedtuple as _namedtuple
-    DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent')
+    DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent', module='decimal')
 except ImportError:
    DecimalTuple = lambda *args: args

@@ -172,6 +78,7 @@ ROUND_05UP = 'ROUND_05UP'

 # Compatibility with the C version
 HAVE_THREADS = True
+HAVE_CONTEXTVAR = True
 if sys.maxsize == 2**63-1:
    MAX_PREC = 999999999999999999
    MAX_EMAX = 999999999999999999
@@ -190,7 +97,7 @@ class DecimalException(ArithmeticError):

    Used exceptions derive from this.
    If an exception derives from another exception besides this (such as
-    Underflow (Inexact, Rounded, Subnormal) that indicates that it is only
+    Underflow (Inexact, Rounded, Subnormal)) that indicates that it is only
    called if the others are present.  This isn't actually used for
    anything, though.

@@ -238,7 +145,7 @@ class InvalidOperation(DecimalException):
    x ** (+-)INF
    An operand is invalid

-    The result of the operation after these is a quiet positive NaN,
+    The result of the operation after this is a quiet positive NaN,
    except when the cause is a signaling NaN, in which case the result is
    also a quiet NaN, but with the original sign, and an optional
    diagnostic information.
@@ -431,82 +338,40 @@ _rounding_modes = (ROUND_DOWN, ROUND_HALF_UP, ROUND_HALF_EVEN, ROUND_CEILING,
 ##### Context Functions ##################################################

 # The getcontext() and setcontext() function manage access to a thread-local
-# current context.  Py2.4 offers direct support for thread locals.  If that
-# is not available, use threading.current_thread() which is slower but will
-# work for older Pythons.  If threads are not part of the build, create a
-# mock threading object with threading.local() returning the module namespace.
+# current context.

-try:
-    import threading
-except ImportError:
-    # Python was compiled without threads; create a mock object instead
-    class MockThreading(object):
-        def local(self, sys=sys):
-            return sys.modules[__xname__]
-    threading = MockThreading()
-    del MockThreading
+import contextvars

-try:
-    threading.local
+_current_context_var = contextvars.ContextVar('decimal_context')

-except AttributeError:
+_context_attributes = frozenset(
+    ['prec', 'Emin', 'Emax', 'capitals', 'clamp', 'rounding', 'flags', 'traps']
+)

-    # To fix reloading, force it to create a new context
-    # Old contexts have different exceptions in their dicts, making problems.
-    if hasattr(threading.current_thread(), '__decimal_context__'):
-        del threading.current_thread().__decimal_context__
+def getcontext():
+    """Returns this thread's context.

-    def setcontext(context):
-        """Set this thread's context to context."""
-        if context in (DefaultContext, BasicContext, ExtendedContext):
-            context = context.copy()
-            context.clear_flags()
-        threading.current_thread().__decimal_context__ = context
+    If this thread does not yet have a context, returns
+    a new context and sets this thread's context.
+    New contexts are copies of DefaultContext.
+    """
+    try:
+        return _current_context_var.get()
+    except LookupError:
+        context = Context()
+        _current_context_var.set(context)
+        return context

-    def getcontext():
-        """Returns this thread's context.
+def setcontext(context):
+    """Set this thread's context to context."""
+    if context in (DefaultContext, BasicContext, ExtendedContext):
+        context = context.copy()
+        context.clear_flags()
+    _current_context_var.set(context)

-        If this thread does not yet have a context, returns
-        a new context and sets this thread's context.
-        New contexts are copies of DefaultContext.
-        """
-        try:
-            return threading.current_thread().__decimal_context__
-        except AttributeError:
-            context = Context()
-            threading.current_thread().__decimal_context__ = context
-            return context
+del contextvars        # Don't contaminate the namespace

-else:
-
-    local = threading.local()
-    if hasattr(local, '__decimal_context__'):
-        del local.__decimal_context__
-
-    def getcontext(_local=local):
-        """Returns this thread's context.
-
-        If this thread does not yet have a context, returns
-        a new context and sets this thread's context.
-        New contexts are copies of DefaultContext.
-        """
-        try:
-            return _local.__decimal_context__
-        except AttributeError:
-            context = Context()
-            _local.__decimal_context__ = context
-            return context
-
-    def setcontext(context, _local=local):
-        """Set this thread's context to context."""
-        if context in (DefaultContext, BasicContext, ExtendedContext):
-            context = context.copy()
-            context.clear_flags()
-        _local.__decimal_context__ = context
-
-    del threading, local        # Don't contaminate the namespace
-
-def localcontext(ctx=None):
+def localcontext(ctx=None, **kwargs):
    """Return a context manager for a copy of the supplied context

    Uses a copy of the current context if no context is specified
@@ -542,8 +407,14 @@ def localcontext(ctx=None):
    >>> print(getcontext().prec)
    28
    """
-    if ctx is None: ctx = getcontext()
-    return _ContextManager(ctx)
+    if ctx is None:
+        ctx = getcontext()
+    ctx_manager = _ContextManager(ctx)
+    for key, value in kwargs.items():
+        if key not in _context_attributes:
+            raise TypeError(f"'{key}' is an invalid keyword argument for this function")
+        setattr(ctx_manager.new_context, key, value)
+    return ctx_manager


 ##### Decimal class #######################################################
@@ -553,7 +424,7 @@ def localcontext(ctx=None):
 # numbers.py for more detail.

 class Decimal(object):
-    """Floating point class for decimal arithmetic."""
+    """Floating-point class for decimal arithmetic."""

    __slots__ = ('_exp','_int','_sign', '_is_special')
    # Generally, the value of the Decimal instance is given by
@@ -734,18 +605,23 @@ class Decimal(object):

        """
        if isinstance(f, int):                # handle integer inputs
-            return cls(f)
-        if not isinstance(f, float):
-            raise TypeError("argument must be int or float.")
-        if _math.isinf(f) or _math.isnan(f):
-            return cls(repr(f))
-        if _math.copysign(1.0, f) == 1.0:
-            sign = 0
+            sign = 0 if f >= 0 else 1
+            k = 0
+            coeff = str(abs(f))
+        elif isinstance(f, float):
+            if _math.isinf(f) or _math.isnan(f):
+                return cls(repr(f))
+            if _math.copysign(1.0, f) == 1.0:
+                sign = 0
+            else:
+                sign = 1
+            n, d = abs(f).as_integer_ratio()
+            k = d.bit_length() - 1
+            coeff = str(n*5**k)
        else:
-            sign = 1
-        n, d = abs(f).as_integer_ratio()
-        k = d.bit_length() - 1
-        result = _dec_from_triple(sign, str(n*5**k), -k)
+            raise TypeError("argument must be int or float.")
+
+        result = _dec_from_triple(sign, coeff, -k)
        if cls is Decimal:
            return result
        else:
@@ -988,7 +864,7 @@ class Decimal(object):
            if self.is_snan():
                raise TypeError('Cannot hash a signaling NaN value.')
            elif self.is_nan():
-                return _PyHASH_NAN
+                return object.__hash__(self)
            else:
                if self._sign:
                    return -_PyHASH_INF
@@ -1669,13 +1545,13 @@ class Decimal(object):

    __trunc__ = __int__

+    @property
    def real(self):
        return self
-    real = property(real)

+    @property
    def imag(self):
        return Decimal(0)
-    imag = property(imag)

    def conjugate(self):
        return self
@@ -2255,10 +2131,16 @@ class Decimal(object):
            else:
                return None

-            if xc >= 10**p:
+            # An exact power of 10 is representable, but can convert to a
+            # string of any length. But an exact power of 10 shouldn't be
+            # possible at this point.
+            assert xc > 1, self
+            assert xc % 10 != 0, self
+            strxc = str(xc)
+            if len(strxc) > p:
                return None
            xe = -e-xe
-            return _dec_from_triple(0, str(xc), xe)
+            return _dec_from_triple(0, strxc, xe)

        # now y is positive; find m and n such that y = m/n
        if ye >= 0:
@@ -2267,7 +2149,7 @@ class Decimal(object):
            if xe != 0 and len(str(abs(yc*xe))) <= -ye:
                return None
            xc_bits = _nbits(xc)
-            if xc != 1 and len(str(abs(yc)*xc_bits)) <= -ye:
+            if len(str(abs(yc)*xc_bits)) <= -ye:
                return None
            m, n = yc, 10**(-ye)
            while m % 2 == n % 2 == 0:
@@ -2280,7 +2162,7 @@ class Decimal(object):
        # compute nth root of xc*10**xe
        if n > 1:
            # if 1 < xc < 2**n then xc isn't an nth power
-            if xc != 1 and xc_bits <= n:
+            if xc_bits <= n:
                return None

            xe, rem = divmod(xe, n)
@@ -2308,13 +2190,18 @@ class Decimal(object):
            return None
        xc = xc**m
        xe *= m
-        if xc > 10**p:
+        # An exact power of 10 is representable, but can convert to a string
+        # of any length. But an exact power of 10 shouldn't be possible at
+        # this point.
+        assert xc > 1, self
+        assert xc % 10 != 0, self
+        str_xc = str(xc)
+        if len(str_xc) > p:
            return None

        # by this point the result *is* exactly representable
        # adjust the exponent to get as close as possible to the ideal
        # exponent, if necessary
-        str_xc = str(xc)
        if other._isinteger() and other._sign == 0:
            ideal_exponent = self._exp*int(other)
            zeros = min(xe-ideal_exponent, p-len(str_xc))
@@ -3832,6 +3719,10 @@ class Decimal(object):
        # represented in fixed point; rescale them to 0e0.
        if not self and self._exp > 0 and spec['type'] in 'fF%':
            self = self._rescale(0, rounding)
+        if not self and spec['no_neg_0'] and self._sign:
+            adjusted_sign = 0
+        else:
+            adjusted_sign = self._sign

        # figure out placement of the decimal point
        leftdigits = self._exp + len(self._int)
@@ -3862,7 +3753,7 @@ class Decimal(object):

        # done with the decimal-specific stuff;  hand over the rest
        # of the formatting to the _format_number function
-        return _format_number(self._sign, intpart, fracpart, exp, spec)
+        return _format_number(adjusted_sign, intpart, fracpart, exp, spec)

 def _dec_from_triple(sign, coefficient, exponent, special=False):
    """Create a decimal instance directly, without any validation,
@@ -5672,8 +5563,6 @@ class _WorkRep(object):
    def __repr__(self):
        return "(%r, %r, %r)" % (self.sign, self.int, self.exp)

-    __str__ = __repr__
-


 def _normalize(op1, op2, prec = 0):
@@ -6182,7 +6071,7 @@ _exact_half = re.compile('50*$').match
 #
 # A format specifier for Decimal looks like:
 #
-#   [[fill]align][sign][#][0][minimumwidth][,][.precision][type]
+#   [[fill]align][sign][z][#][0][minimumwidth][,][.precision][type]

 _parse_format_specifier_regex = re.compile(r"""\A
 (?:
@@ -6190,6 +6079,7 @@ _parse_format_specifier_regex = re.compile(r"""\A
   (?P<align>[<>=^])
 )?
 (?P<sign>[-+ ])?
+(?P<no_neg_0>z)?
 (?P<alt>\#)?
 (?P<zeropad>0)?
 (?P<minimumwidth>(?!0)\d+)?
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -44,8 +44,9 @@ def text_encoding(encoding, stacklevel=2):
    """
    A helper function to choose the text encoding.

-    When encoding is not None, just return it.
-    Otherwise, return the default text encoding (i.e. "locale").
+    When encoding is not None, this function returns it.
+    Otherwise, this function returns the default text encoding
+    (i.e. "locale" or "utf-8" depends on UTF-8 mode).

    This function emits an EncodingWarning if *encoding* is None and
    sys.flags.warn_default_encoding is true.
@@ -55,7 +56,10 @@ def text_encoding(encoding, stacklevel=2):
    However, please consider using encoding="utf-8" for new APIs.
    """
    if encoding is None:
-        encoding = "locale"
+        if sys.flags.utf8_mode:
+            encoding = "utf-8"
+        else:
+            encoding = "locale"
        if sys.flags.warn_default_encoding:
            import warnings
            warnings.warn("'encoding' argument not specified.",
@@ -101,7 +105,6 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None,
    'b'       binary mode
    't'       text mode (default)
    '+'       open a disk file for updating (reading and writing)
-    'U'       universal newline mode (deprecated)
    ========= ===============================================================

    The default mode is 'rt' (open for reading text). For binary random
@@ -117,10 +120,6 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None,
    returned as strings, the bytes having been first decoded using a
    platform-dependent encoding or using the specified encoding if given.

-    'U' mode is deprecated and will raise an exception in future versions
-    of Python.  It has no effect in Python 3.  Use newline to control
-    universal newlines mode.
-
    buffering is an optional integer used to set the buffering policy.
    Pass 0 to switch buffering off (only allowed in binary mode), 1 to select
    line buffering (only usable in text mode), and an integer > 1 to indicate
@@ -206,7 +205,7 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None,
    if errors is not None and not isinstance(errors, str):
        raise TypeError("invalid errors: %r" % errors)
    modes = set(mode)
-    if modes - set("axrwb+tU") or len(mode) > len(modes):
+    if modes - set("axrwb+t") or len(mode) > len(modes):
        raise ValueError("invalid mode: %r" % mode)
    creating = "x" in modes
    reading = "r" in modes
@@ -215,13 +214,6 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None,
    updating = "+" in modes
    text = "t" in modes
    binary = "b" in modes
-    if "U" in modes:
-        if creating or writing or appending or updating:
-            raise ValueError("mode U cannot be combined with 'x', 'w', 'a', or '+'")
-        import warnings
-        warnings.warn("'U' mode is deprecated",
-                      DeprecationWarning, 2)
-        reading = True
    if text and binary:
        raise ValueError("can't have text and binary mode at once")
    if creating + reading + writing + appending > 1:
@@ -311,22 +303,6 @@ except AttributeError:
    open_code = _open_code_with_warning


-def __getattr__(name):
-    if name == "OpenWrapper":
-        # bpo-43680: Until Python 3.9, _pyio.open was not a static method and
-        # builtins.open was set to OpenWrapper to not become a bound method
-        # when set to a class variable. _io.open is a built-in function whereas
-        # _pyio.open is a Python function. In Python 3.10, _pyio.open() is now
-        # a static method, and builtins.open() is now io.open().
-        import warnings
-        warnings.warn('OpenWrapper is deprecated, use open instead',
-                      DeprecationWarning, stacklevel=2)
-        global OpenWrapper
-        OpenWrapper = open
-        return OpenWrapper
-    raise AttributeError(name)
-
-
 # In normal operation, both `UnsupportedOperation`s should be bound to the
 # same object.
 try:
@@ -338,8 +314,7 @@ except AttributeError:

 class IOBase(metaclass=abc.ABCMeta):

-    """The abstract base class for all I/O classes, acting on streams of
-    bytes. There is no public constructor.
+    """The abstract base class for all I/O classes.

    This class provides dummy implementations for many methods that
    derived classes can override selectively; the default implementations
@@ -1154,6 +1129,7 @@ class BufferedReader(_BufferedIOMixin):
        do at most one raw read to satisfy it.  We never return more
        than self.buffer_size.
        """
+        self._checkClosed("peek of closed file")
        with self._read_lock:
            return self._peek_unlocked(size)

@@ -1172,6 +1148,7 @@ class BufferedReader(_BufferedIOMixin):
        """Reads up to size bytes, with at most one read() system call."""
        # Returns up to size bytes.  If at least one byte is buffered, we
        # only return buffered bytes.  Otherwise, we do one raw read.
+        self._checkClosed("read of closed file")
        if size < 0:
            size = self.buffer_size
        if size == 0:
@@ -1189,6 +1166,8 @@ class BufferedReader(_BufferedIOMixin):
    def _readinto(self, buf, read1):
        """Read data into *buf* with at most one system call."""

+        self._checkClosed("readinto of closed file")
+
        # Need to create a memoryview object of type 'b', otherwise
        # we may not be able to assign bytes to it, and slicing it
        # would create a new object.
@@ -1233,11 +1212,13 @@ class BufferedReader(_BufferedIOMixin):
        return written

    def tell(self):
-        return _BufferedIOMixin.tell(self) - len(self._read_buf) + self._read_pos
+        # GH-95782: Keep return value non-negative
+        return max(_BufferedIOMixin.tell(self) - len(self._read_buf) + self._read_pos, 0)

    def seek(self, pos, whence=0):
        if whence not in valid_seek_flags:
            raise ValueError("invalid whence value")
+        self._checkClosed("seek of closed file")
        with self._read_lock:
            if whence == 1:
                pos -= len(self._read_buf) - self._read_pos
@@ -1845,7 +1826,7 @@ class TextIOBase(IOBase):
    """Base class for text I/O.

    This class provides a character and line based interface to stream
-    I/O. There is no public constructor.
+    I/O.
    """

    def read(self, size=-1):
@@ -1997,7 +1978,7 @@ class TextIOWrapper(TextIOBase):
    r"""Character and line based layer over a BufferedIOBase object, buffer.

    encoding gives the name of the encoding that the stream will be
-    decoded or encoded with. It defaults to locale.getpreferredencoding(False).
+    decoded or encoded with. It defaults to locale.getencoding().

    errors determines the strictness of encoding and decoding (see the
    codecs.register) and defaults to "strict".
@@ -2031,19 +2012,7 @@ class TextIOWrapper(TextIOBase):
        encoding = text_encoding(encoding)

        if encoding == "locale":
-            try:
-                encoding = os.device_encoding(buffer.fileno()) or "locale"
-            except (AttributeError, UnsupportedOperation):
-                pass
-
-        if encoding == "locale":
-            try:
-                import locale
-            except ImportError:
-                # Importing locale may fail if Python is being built
-                encoding = "utf-8"
-            else:
-                encoding = locale.getpreferredencoding(False)
+            encoding = self._get_locale_encoding()

        if not isinstance(encoding, str):
            raise ValueError("invalid encoding: %r" % encoding)
@@ -2176,6 +2145,8 @@ class TextIOWrapper(TextIOBase):
        else:
            if not isinstance(encoding, str):
                raise TypeError("invalid encoding: %r" % encoding)
+            if encoding == "locale":
+                encoding = self._get_locale_encoding()

        if newline is Ellipsis:
            newline = self._readnl
@@ -2243,8 +2214,9 @@ class TextIOWrapper(TextIOBase):
        self.buffer.write(b)
        if self._line_buffering and (haslf or "\r" in s):
            self.flush()
-        self._set_decoded_chars('')
-        self._snapshot = None
+        if self._snapshot is not None:
+            self._set_decoded_chars('')
+            self._snapshot = None
        if self._decoder:
            self._decoder.reset()
        return length
@@ -2280,6 +2252,15 @@ class TextIOWrapper(TextIOBase):
        self._decoded_chars_used += len(chars)
        return chars

+    def _get_locale_encoding(self):
+        try:
+            import locale
+        except ImportError:
+            # Importing locale may fail if Python is being built
+            return "utf-8"
+        else:
+            return locale.getencoding()
+
    def _rewind_decoded_chars(self, n):
        """Rewind the _decoded_chars buffer."""
        if self._decoded_chars_used < n:
@@ -2549,8 +2530,9 @@ class TextIOWrapper(TextIOBase):
            # Read everything.
            result = (self._get_decoded_chars() +
                      decoder.decode(self.buffer.read(), final=True))
-            self._set_decoded_chars('')
-            self._snapshot = None
+            if self._snapshot is not None:
+                self._set_decoded_chars('')
+                self._snapshot = None
            return result
        else:
            # Keep reading chunks until we have size characters to return.
--- a/Lib/_pylong.py
+++ b/Lib/_pylong.py
@@ -0,0 +1,363 @@
+"""Python implementations of some algorithms for use by longobject.c.
+The goal is to provide asymptotically faster algorithms that can be
+used for operations on integers with many digits.  In those cases, the
+performance overhead of the Python implementation is not significant
+since the asymptotic behavior is what dominates runtime. Functions
+provided by this module should be considered private and not part of any
+public API.
+
+Note: for ease of maintainability, please prefer clear code and avoid
+"micro-optimizations".  This module will only be imported and used for
+integers with a huge number of digits.  Saving a few microseconds with
+tricky or non-obvious code is not worth it.  For people looking for
+maximum performance, they should use something like gmpy2."""
+
+import re
+import decimal
+try:
+    import _decimal
+except ImportError:
+    _decimal = None
+
+# A number of functions have this form, where `w` is a desired number of
+# digits in base `base`:
+#
+#    def inner(...w...):
+#        if w <= LIMIT:
+#            return something
+#        lo = w >> 1
+#        hi = w - lo
+#        something involving base**lo, inner(...lo...), j, and inner(...hi...)
+#    figure out largest w needed
+#    result = inner(w)
+#
+# They all had some on-the-fly scheme to cache `base**lo` results for reuse.
+# Power is costly.
+#
+# This routine aims to compute all amd only the needed powers in advance, as
+# efficiently as reasonably possible. This isn't trivial, and all the
+# on-the-fly methods did needless work in many cases. The driving code above
+# changes to:
+#
+#    figure out largest w needed
+#    mycache = compute_powers(w, base, LIMIT)
+#    result = inner(w)
+#
+# and `mycache[lo]` replaces `base**lo` in the inner function.
+#
+# While this does give minor speedups (a few percent at best), the primary
+# intent is to simplify the functions using this, by eliminating the need for
+# them to craft their own ad-hoc caching schemes.
+def compute_powers(w, base, more_than, show=False):
+    seen = set()
+    need = set()
+    ws = {w}
+    while ws:
+        w = ws.pop() # any element is fine to use next
+        if w in seen or w <= more_than:
+            continue
+        seen.add(w)
+        lo = w >> 1
+        # only _need_ lo here; some other path may, or may not, need hi
+        need.add(lo)
+        ws.add(lo)
+        if w & 1:
+            ws.add(lo + 1)
+
+    d = {}
+    if not need:
+        return d
+    it = iter(sorted(need))
+    first = next(it)
+    if show:
+        print("pow at", first)
+    d[first] = base ** first
+    for this in it:
+        if this - 1 in d:
+            if show:
+                print("* base at", this)
+            d[this] = d[this - 1] * base # cheap
+        else:
+            lo = this >> 1
+            hi = this - lo
+            assert lo in d
+            if show:
+                print("square at", this)
+            # Multiplying a bigint by itself (same object!) is about twice
+            # as fast in CPython.
+            sq = d[lo] * d[lo]
+            if hi != lo:
+                assert hi == lo + 1
+                if show:
+                    print("    and * base")
+                sq *= base
+            d[this] = sq
+    return d
+
+_unbounded_dec_context = decimal.getcontext().copy()
+_unbounded_dec_context.prec = decimal.MAX_PREC
+_unbounded_dec_context.Emax = decimal.MAX_EMAX
+_unbounded_dec_context.Emin = decimal.MIN_EMIN
+_unbounded_dec_context.traps[decimal.Inexact] = 1 # sanity check
+
+def int_to_decimal(n):
+    """Asymptotically fast conversion of an 'int' to Decimal."""
+
+    # Function due to Tim Peters.  See GH issue #90716 for details.
+    # https://github.com/python/cpython/issues/90716
+    #
+    # The implementation in longobject.c of base conversion algorithms
+    # between power-of-2 and non-power-of-2 bases are quadratic time.
+    # This function implements a divide-and-conquer algorithm that is
+    # faster for large numbers.  Builds an equal decimal.Decimal in a
+    # "clever" recursive way.  If we want a string representation, we
+    # apply str to _that_.
+
+    from decimal import Decimal as D
+    BITLIM = 200
+
+    # Don't bother caching the "lo" mask in this; the time to compute it is
+    # tiny compared to the multiply.
+    def inner(n, w):
+        if w <= BITLIM:
+            return D(n)
+        w2 = w >> 1
+        hi = n >> w2
+        lo = n & ((1 << w2) - 1)
+        return inner(lo, w2) + inner(hi, w - w2) * w2pow[w2]
+
+    with decimal.localcontext(_unbounded_dec_context):
+        nbits = n.bit_length()
+        w2pow = compute_powers(nbits, D(2), BITLIM)
+        if n < 0:
+            negate = True
+            n = -n
+        else:
+            negate = False
+        result = inner(n, nbits)
+        if negate:
+            result = -result
+    return result
+
+def int_to_decimal_string(n):
+    """Asymptotically fast conversion of an 'int' to a decimal string."""
+    w = n.bit_length()
+    if w > 450_000 and _decimal is not None:
+        # It is only usable with the C decimal implementation.
+        # _pydecimal.py calls str() on very large integers, which in its
+        # turn calls int_to_decimal_string(), causing very deep recursion.
+        return str(int_to_decimal(n))
+
+    # Fallback algorithm for the case when the C decimal module isn't
+    # available.  This algorithm is asymptotically worse than the algorithm
+    # using the decimal module, but better than the quadratic time
+    # implementation in longobject.c.
+
+    DIGLIM = 1000
+    def inner(n, w):
+        if w <= DIGLIM:
+            return str(n)
+        w2 = w >> 1
+        hi, lo = divmod(n, pow10[w2])
+        return inner(hi, w - w2) + inner(lo, w2).zfill(w2)
+
+    # The estimation of the number of decimal digits.
+    # There is no harm in small error.  If we guess too large, there may
+    # be leading 0's that need to be stripped.  If we guess too small, we
+    # may need to call str() recursively for the remaining highest digits,
+    # which can still potentially be a large integer. This is manifested
+    # only if the number has way more than 10**15 digits, that exceeds
+    # the 52-bit physical address limit in both Intel64 and AMD64.
+    w = int(w * 0.3010299956639812 + 1)  # log10(2)
+    pow10 = compute_powers(w, 5, DIGLIM)
+    for k, v in pow10.items():
+        pow10[k] = v << k # 5**k << k == 5**k * 2**k == 10**k
+    if n < 0:
+        n = -n
+        sign = '-'
+    else:
+        sign = ''
+    s = inner(n, w)
+    if s[0] == '0' and n:
+        # If our guess of w is too large, there may be leading 0's that
+        # need to be stripped.
+        s = s.lstrip('0')
+    return sign + s
+
+def _str_to_int_inner(s):
+    """Asymptotically fast conversion of a 'str' to an 'int'."""
+
+    # Function due to Bjorn Martinsson.  See GH issue #90716 for details.
+    # https://github.com/python/cpython/issues/90716
+    #
+    # The implementation in longobject.c of base conversion algorithms
+    # between power-of-2 and non-power-of-2 bases are quadratic time.
+    # This function implements a divide-and-conquer algorithm making use
+    # of Python's built in big int multiplication. Since Python uses the
+    # Karatsuba algorithm for multiplication, the time complexity
+    # of this function is O(len(s)**1.58).
+
+    DIGLIM = 2048
+
+    def inner(a, b):
+        if b - a <= DIGLIM:
+            return int(s[a:b])
+        mid = (a + b + 1) >> 1
+        return (inner(mid, b)
+                + ((inner(a, mid) * w5pow[b - mid])
+                    << (b - mid)))
+
+    w5pow = compute_powers(len(s), 5, DIGLIM)
+    return inner(0, len(s))
+
+
+def int_from_string(s):
+    """Asymptotically fast version of PyLong_FromString(), conversion
+    of a string of decimal digits into an 'int'."""
+    # PyLong_FromString() has already removed leading +/-, checked for invalid
+    # use of underscore characters, checked that string consists of only digits
+    # and underscores, and stripped leading whitespace.  The input can still
+    # contain underscores and have trailing whitespace.
+    s = s.rstrip().replace('_', '')
+    return _str_to_int_inner(s)
+
+def str_to_int(s):
+    """Asymptotically fast version of decimal string to 'int' conversion."""
+    # FIXME: this doesn't support the full syntax that int() supports.
+    m = re.match(r'\s*([+-]?)([0-9_]+)\s*', s)
+    if not m:
+        raise ValueError('invalid literal for int() with base 10')
+    v = int_from_string(m.group(2))
+    if m.group(1) == '-':
+        v = -v
+    return v
+
+
+# Fast integer division, based on code from Mark Dickinson, fast_div.py
+# GH-47701. Additional refinements and optimizations by Bjorn Martinsson.  The
+# algorithm is due to Burnikel and Ziegler, in their paper "Fast Recursive
+# Division".
+
+_DIV_LIMIT = 4000
+
+
+def _div2n1n(a, b, n):
+    """Divide a 2n-bit nonnegative integer a by an n-bit positive integer
+    b, using a recursive divide-and-conquer algorithm.
+
+    Inputs:
+      n is a positive integer
+      b is a positive integer with exactly n bits
+      a is a nonnegative integer such that a < 2**n * b
+
+    Output:
+      (q, r) such that a = b*q+r and 0 <= r < b.
+
+    """
+    if a.bit_length() - n <= _DIV_LIMIT:
+        return divmod(a, b)
+    pad = n & 1
+    if pad:
+        a <<= 1
+        b <<= 1
+        n += 1
+    half_n = n >> 1
+    mask = (1 << half_n) - 1
+    b1, b2 = b >> half_n, b & mask
+    q1, r = _div3n2n(a >> n, (a >> half_n) & mask, b, b1, b2, half_n)
+    q2, r = _div3n2n(r, a & mask, b, b1, b2, half_n)
+    if pad:
+        r >>= 1
+    return q1 << half_n | q2, r
+
+
+def _div3n2n(a12, a3, b, b1, b2, n):
+    """Helper function for _div2n1n; not intended to be called directly."""
+    if a12 >> n == b1:
+        q, r = (1 << n) - 1, a12 - (b1 << n) + b1
+    else:
+        q, r = _div2n1n(a12, b1, n)
+    r = (r << n | a3) - q * b2
+    while r < 0:
+        q -= 1
+        r += b
+    return q, r
+
+
+def _int2digits(a, n):
+    """Decompose non-negative int a into base 2**n
+
+    Input:
+      a is a non-negative integer
+
+    Output:
+      List of the digits of a in base 2**n in little-endian order,
+      meaning the most significant digit is last. The most
+      significant digit is guaranteed to be non-zero.
+      If a is 0 then the output is an empty list.
+
+    """
+    a_digits = [0] * ((a.bit_length() + n - 1) // n)
+
+    def inner(x, L, R):
+        if L + 1 == R:
+            a_digits[L] = x
+            return
+        mid = (L + R) >> 1
+        shift = (mid - L) * n
+        upper = x >> shift
+        lower = x ^ (upper << shift)
+        inner(lower, L, mid)
+        inner(upper, mid, R)
+
+    if a:
+        inner(a, 0, len(a_digits))
+    return a_digits
+
+
+def _digits2int(digits, n):
+    """Combine base-2**n digits into an int. This function is the
+    inverse of `_int2digits`. For more details, see _int2digits.
+    """
+
+    def inner(L, R):
+        if L + 1 == R:
+            return digits[L]
+        mid = (L + R) >> 1
+        shift = (mid - L) * n
+        return (inner(mid, R) << shift) + inner(L, mid)
+
+    return inner(0, len(digits)) if digits else 0
+
+
+def _divmod_pos(a, b):
+    """Divide a non-negative integer a by a positive integer b, giving
+    quotient and remainder."""
+    # Use grade-school algorithm in base 2**n, n = nbits(b)
+    n = b.bit_length()
+    a_digits = _int2digits(a, n)
+
+    r = 0
+    q_digits = []
+    for a_digit in reversed(a_digits):
+        q_digit, r = _div2n1n((r << n) + a_digit, b, n)
+        q_digits.append(q_digit)
+    q_digits.reverse()
+    q = _digits2int(q_digits, n)
+    return q, r
+
+
+def int_divmod(a, b):
+    """Asymptotically fast replacement for divmod, for 'int'.
+    Its time complexity is O(n**1.58), where n = #bits(a) + #bits(b).
+    """
+    if b == 0:
+        raise ZeroDivisionError
+    elif b < 0:
+        q, r = int_divmod(-a, -b)
+        return q, -r
+    elif a < 0:
+        q, r = int_divmod(~a, b)
+        return ~q, b + ~r
+    else:
+        return _divmod_pos(a, b)
--- a/Lib/_pyrepl/init.py
+++ b/Lib/_pyrepl/init.py
@@ -0,0 +1,19 @@
+#   Copyright 2000-2008 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
--- a/Lib/_pyrepl/main.py
+++ b/Lib/_pyrepl/main.py
@@ -0,0 +1,6 @@
+# Important: don't add things to this module, as they will end up in the REPL's
+# default globals.  Use _pyrepl.main instead.
+
+if __name__ == "__main__":
+    from .main import interactive_console as __pyrepl_interactive_console
+    __pyrepl_interactive_console()
--- a/Lib/_pyrepl/_minimal_curses.py
+++ b/Lib/_pyrepl/_minimal_curses.py
@@ -0,0 +1,68 @@
+"""Minimal '_curses' module, the low-level interface for curses module
+which is not meant to be used directly.
+
+Based on ctypes.  It's too incomplete to be really called '_curses', so
+to use it, you have to import it and stick it in sys.modules['_curses']
+manually.
+
+Note that there is also a built-in module _minimal_curses which will
+hide this one if compiled in.
+"""
+
+import ctypes
+import ctypes.util
+
+
+class error(Exception):
+    pass
+
+
+def _find_clib() -> str:
+    trylibs = ["ncursesw", "ncurses", "curses"]
+
+    for lib in trylibs:
+        path = ctypes.util.find_library(lib)
+        if path:
+            return path
+    raise ModuleNotFoundError("curses library not found", name="_pyrepl._minimal_curses")
+
+
+_clibpath = _find_clib()
+clib = ctypes.cdll.LoadLibrary(_clibpath)
+
+clib.setupterm.argtypes = [ctypes.c_char_p, ctypes.c_int, ctypes.POINTER(ctypes.c_int)]
+clib.setupterm.restype = ctypes.c_int
+
+clib.tigetstr.argtypes = [ctypes.c_char_p]
+clib.tigetstr.restype = ctypes.c_ssize_t
+
+clib.tparm.argtypes = [ctypes.c_char_p] + 9 * [ctypes.c_int]  # type: ignore[operator]
+clib.tparm.restype = ctypes.c_char_p
+
+OK = 0
+ERR = -1
+
+# ____________________________________________________________
+
+
+def setupterm(termstr, fd):
+    err = ctypes.c_int(0)
+    result = clib.setupterm(termstr, fd, ctypes.byref(err))
+    if result == ERR:
+        raise error("setupterm() failed (err=%d)" % err.value)
+
+
+def tigetstr(cap):
+    if not isinstance(cap, bytes):
+        cap = cap.encode("ascii")
+    result = clib.tigetstr(cap)
+    if result == ERR:
+        return None
+    return ctypes.cast(result, ctypes.c_char_p).value
+
+
+def tparm(str, i1=0, i2=0, i3=0, i4=0, i5=0, i6=0, i7=0, i8=0, i9=0):
+    result = clib.tparm(str, i1, i2, i3, i4, i5, i6, i7, i8, i9)
+    if result is None:
+        raise error("tparm() returned NULL")
+    return result
--- a/Lib/_pyrepl/_threading_handler.py
+++ b/Lib/_pyrepl/_threading_handler.py
@@ -0,0 +1,74 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+import traceback
+
+
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from threading import Thread
+    from types import TracebackType
+    from typing import Protocol
+
+    class ExceptHookArgs(Protocol):
+        @property
+        def exc_type(self) -> type[BaseException]: ...
+        @property
+        def exc_value(self) -> BaseException | None: ...
+        @property
+        def exc_traceback(self) -> TracebackType | None: ...
+        @property
+        def thread(self) -> Thread | None: ...
+
+    class ShowExceptions(Protocol):
+        def __call__(self) -> int: ...
+        def add(self, s: str) -> None: ...
+
+    from .reader import Reader
+
+
+def install_threading_hook(reader: Reader) -> None:
+    import threading
+
+    @dataclass
+    class ExceptHookHandler:
+        lock: threading.Lock = field(default_factory=threading.Lock)
+        messages: list[str] = field(default_factory=list)
+
+        def show(self) -> int:
+            count = 0
+            with self.lock:
+                if not self.messages:
+                    return 0
+                reader.restore()
+                for tb in self.messages:
+                    count += 1
+                    if tb:
+                        print(tb)
+                self.messages.clear()
+                reader.scheduled_commands.append("ctrl-c")
+                reader.prepare()
+            return count
+
+        def add(self, s: str) -> None:
+            with self.lock:
+                self.messages.append(s)
+
+        def exception(self, args: ExceptHookArgs) -> None:
+            lines = traceback.format_exception(
+                args.exc_type,
+                args.exc_value,
+                args.exc_traceback,
+                colorize=reader.can_colorize,
+            )  # type: ignore[call-overload]
+            pre = f"\nException in {args.thread.name}:\n" if args.thread else "\n"
+            tb = pre + "".join(lines)
+            self.add(tb)
+
+        def __call__(self) -> int:
+            return self.show()
+
+
+    handler = ExceptHookHandler()
+    reader.threading_hook = handler
+    threading.excepthook = handler.exception
--- a/Lib/_pyrepl/commands.py
+++ b/Lib/_pyrepl/commands.py
@@ -0,0 +1,489 @@
+#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Antonio Cuni
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from __future__ import annotations
+import os
+
+# Categories of actions:
+#  killing
+#  yanking
+#  motion
+#  editing
+#  history
+#  finishing
+# [completion]
+
+
+# types
+if False:
+    from .historical_reader import HistoricalReader
+
+
+class Command:
+    finish: bool = False
+    kills_digit_arg: bool = True
+
+    def __init__(
+        self, reader: HistoricalReader, event_name: str, event: list[str]
+    ) -> None:
+        # Reader should really be "any reader" but there's too much usage of
+        # HistoricalReader methods and fields in the code below for us to
+        # refactor at the moment.
+
+        self.reader = reader
+        self.event = event
+        self.event_name = event_name
+
+    def do(self) -> None:
+        pass
+
+
+class KillCommand(Command):
+    def kill_range(self, start: int, end: int) -> None:
+        if start == end:
+            return
+        r = self.reader
+        b = r.buffer
+        text = b[start:end]
+        del b[start:end]
+        if is_kill(r.last_command):
+            if start < r.pos:
+                r.kill_ring[-1] = text + r.kill_ring[-1]
+            else:
+                r.kill_ring[-1] = r.kill_ring[-1] + text
+        else:
+            r.kill_ring.append(text)
+        r.pos = start
+        r.dirty = True
+
+
+class YankCommand(Command):
+    pass
+
+
+class MotionCommand(Command):
+    pass
+
+
+class EditCommand(Command):
+    pass
+
+
+class FinishCommand(Command):
+    finish = True
+    pass
+
+
+def is_kill(command: type[Command] | None) -> bool:
+    return command is not None and issubclass(command, KillCommand)
+
+
+def is_yank(command: type[Command] | None) -> bool:
+    return command is not None and issubclass(command, YankCommand)
+
+
+# etc
+
+
+class digit_arg(Command):
+    kills_digit_arg = False
+
+    def do(self) -> None:
+        r = self.reader
+        c = self.event[-1]
+        if c == "-":
+            if r.arg is not None:
+                r.arg = -r.arg
+            else:
+                r.arg = -1
+        else:
+            d = int(c)
+            if r.arg is None:
+                r.arg = d
+            else:
+                if r.arg < 0:
+                    r.arg = 10 * r.arg - d
+                else:
+                    r.arg = 10 * r.arg + d
+        r.dirty = True
+
+
+class clear_screen(Command):
+    def do(self) -> None:
+        r = self.reader
+        r.console.clear()
+        r.dirty = True
+
+
+class refresh(Command):
+    def do(self) -> None:
+        self.reader.dirty = True
+
+
+class repaint(Command):
+    def do(self) -> None:
+        self.reader.dirty = True
+        self.reader.console.repaint()
+
+
+class kill_line(KillCommand):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        eol = r.eol()
+        for c in b[r.pos : eol]:
+            if not c.isspace():
+                self.kill_range(r.pos, eol)
+                return
+        else:
+            self.kill_range(r.pos, eol + 1)
+
+
+class unix_line_discard(KillCommand):
+    def do(self) -> None:
+        r = self.reader
+        self.kill_range(r.bol(), r.pos)
+
+
+class unix_word_rubout(KillCommand):
+    def do(self) -> None:
+        r = self.reader
+        for i in range(r.get_arg()):
+            self.kill_range(r.bow(), r.pos)
+
+
+class kill_word(KillCommand):
+    def do(self) -> None:
+        r = self.reader
+        for i in range(r.get_arg()):
+            self.kill_range(r.pos, r.eow())
+
+
+class backward_kill_word(KillCommand):
+    def do(self) -> None:
+        r = self.reader
+        for i in range(r.get_arg()):
+            self.kill_range(r.bow(), r.pos)
+
+
+class yank(YankCommand):
+    def do(self) -> None:
+        r = self.reader
+        if not r.kill_ring:
+            r.error("nothing to yank")
+            return
+        r.insert(r.kill_ring[-1])
+
+
+class yank_pop(YankCommand):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        if not r.kill_ring:
+            r.error("nothing to yank")
+            return
+        if not is_yank(r.last_command):
+            r.error("previous command was not a yank")
+            return
+        repl = len(r.kill_ring[-1])
+        r.kill_ring.insert(0, r.kill_ring.pop())
+        t = r.kill_ring[-1]
+        b[r.pos - repl : r.pos] = t
+        r.pos = r.pos - repl + len(t)
+        r.dirty = True
+
+
+class interrupt(FinishCommand):
+    def do(self) -> None:
+        import signal
+
+        self.reader.console.finish()
+        self.reader.finish()
+        os.kill(os.getpid(), signal.SIGINT)
+
+
+class ctrl_c(Command):
+    def do(self) -> None:
+        self.reader.console.finish()
+        self.reader.finish()
+        raise KeyboardInterrupt
+
+
+class suspend(Command):
+    def do(self) -> None:
+        import signal
+
+        r = self.reader
+        p = r.pos
+        r.console.finish()
+        os.kill(os.getpid(), signal.SIGSTOP)
+        ## this should probably be done
+        ## in a handler for SIGCONT?
+        r.console.prepare()
+        r.pos = p
+        # r.posxy = 0, 0  # XXX this is invalid
+        r.dirty = True
+        r.console.screen = []
+
+
+class up(MotionCommand):
+    def do(self) -> None:
+        r = self.reader
+        for _ in range(r.get_arg()):
+            x, y = r.pos2xy()
+            new_y = y - 1
+
+            if r.bol() == 0:
+                if r.historyi > 0:
+                    r.select_item(r.historyi - 1)
+                    return
+                r.pos = 0
+                r.error("start of buffer")
+                return
+
+            if (
+                x
+                > (
+                    new_x := r.max_column(new_y)
+                )  # we're past the end of the previous line
+                or x == r.max_column(y)
+                and any(
+                    not i.isspace() for i in r.buffer[r.bol() :]
+                )  # move between eols
+            ):
+                x = new_x
+
+            r.setpos_from_xy(x, new_y)
+
+
+class down(MotionCommand):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        for _ in range(r.get_arg()):
+            x, y = r.pos2xy()
+            new_y = y + 1
+
+            if r.eol() == len(b):
+                if r.historyi < len(r.history):
+                    r.select_item(r.historyi + 1)
+                    r.pos = r.eol(0)
+                    return
+                r.pos = len(b)
+                r.error("end of buffer")
+                return
+
+            if (
+                x
+                > (
+                    new_x := r.max_column(new_y)
+                )  # we're past the end of the previous line
+                or x == r.max_column(y)
+                and any(
+                    not i.isspace() for i in r.buffer[r.bol() :]
+                )  # move between eols
+            ):
+                x = new_x
+
+            r.setpos_from_xy(x, new_y)
+
+
+class left(MotionCommand):
+    def do(self) -> None:
+        r = self.reader
+        for _ in range(r.get_arg()):
+            p = r.pos - 1
+            if p >= 0:
+                r.pos = p
+            else:
+                self.reader.error("start of buffer")
+
+
+class right(MotionCommand):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        for _ in range(r.get_arg()):
+            p = r.pos + 1
+            if p <= len(b):
+                r.pos = p
+            else:
+                self.reader.error("end of buffer")
+
+
+class beginning_of_line(MotionCommand):
+    def do(self) -> None:
+        self.reader.pos = self.reader.bol()
+
+
+class end_of_line(MotionCommand):
+    def do(self) -> None:
+        self.reader.pos = self.reader.eol()
+
+
+class home(MotionCommand):
+    def do(self) -> None:
+        self.reader.pos = 0
+
+
+class end(MotionCommand):
+    def do(self) -> None:
+        self.reader.pos = len(self.reader.buffer)
+
+
+class forward_word(MotionCommand):
+    def do(self) -> None:
+        r = self.reader
+        for i in range(r.get_arg()):
+            r.pos = r.eow()
+
+
+class backward_word(MotionCommand):
+    def do(self) -> None:
+        r = self.reader
+        for i in range(r.get_arg()):
+            r.pos = r.bow()
+
+
+class self_insert(EditCommand):
+    def do(self) -> None:
+        r = self.reader
+        text = self.event * r.get_arg()
+        r.insert(text)
+
+
+class insert_nl(EditCommand):
+    def do(self) -> None:
+        r = self.reader
+        r.insert("\n" * r.get_arg())
+
+
+class transpose_characters(EditCommand):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        s = r.pos - 1
+        if s < 0:
+            r.error("cannot transpose at start of buffer")
+        else:
+            if s == len(b):
+                s -= 1
+            t = min(s + r.get_arg(), len(b) - 1)
+            c = b[s]
+            del b[s]
+            b.insert(t, c)
+            r.pos = t
+            r.dirty = True
+
+
+class backspace(EditCommand):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        for i in range(r.get_arg()):
+            if r.pos > 0:
+                r.pos -= 1
+                del b[r.pos]
+                r.dirty = True
+            else:
+                self.reader.error("can't backspace at start")
+
+
+class delete(EditCommand):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        if (
+            r.pos == 0
+            and len(b) == 0  # this is something of a hack
+            and self.event[-1] == "\004"
+        ):
+            r.update_screen()
+            r.console.finish()
+            raise EOFError
+        for i in range(r.get_arg()):
+            if r.pos != len(b):
+                del b[r.pos]
+                r.dirty = True
+            else:
+                self.reader.error("end of buffer")
+
+
+class accept(FinishCommand):
+    def do(self) -> None:
+        pass
+
+
+class help(Command):
+    def do(self) -> None:
+        import _sitebuiltins
+
+        with self.reader.suspend():
+            self.reader.msg = _sitebuiltins._Helper()()  # type: ignore[assignment, call-arg]
+
+
+class invalid_key(Command):
+    def do(self) -> None:
+        pending = self.reader.console.getpending()
+        s = "".join(self.event) + pending.data
+        self.reader.error("`%r' not bound" % s)
+
+
+class invalid_command(Command):
+    def do(self) -> None:
+        s = self.event_name
+        self.reader.error("command `%s' not known" % s)
+
+
+class show_history(Command):
+    def do(self) -> None:
+        from .pager import get_pager
+        from site import gethistoryfile  # type: ignore[attr-defined]
+
+        history = os.linesep.join(self.reader.history[:])
+        self.reader.console.restore()
+        pager = get_pager()
+        pager(history, gethistoryfile())
+        self.reader.console.prepare()
+
+        # We need to copy over the state so that it's consistent between
+        # console and reader, and console does not overwrite/append stuff
+        self.reader.console.screen = self.reader.screen.copy()
+        self.reader.console.posxy = self.reader.cxy
+
+
+class paste_mode(Command):
+
+    def do(self) -> None:
+        self.reader.paste_mode = not self.reader.paste_mode
+        self.reader.dirty = True
+
+
+class enable_bracketed_paste(Command):
+    def do(self) -> None:
+        self.reader.paste_mode = True
+        self.reader.in_bracketed_paste = True
+
+class disable_bracketed_paste(Command):
+    def do(self) -> None:
+        self.reader.paste_mode = False
+        self.reader.in_bracketed_paste = False
+        self.reader.dirty = True
--- a/Lib/_pyrepl/completing_reader.py
+++ b/Lib/_pyrepl/completing_reader.py
@@ -0,0 +1,295 @@
+#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Antonio Cuni
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+
+import re
+from . import commands, console, reader
+from .reader import Reader
+
+
+# types
+Command = commands.Command
+if False:
+    from .types import KeySpec, CommandName
+
+
+def prefix(wordlist: list[str], j: int = 0) -> str:
+    d = {}
+    i = j
+    try:
+        while 1:
+            for word in wordlist:
+                d[word[i]] = 1
+            if len(d) > 1:
+                return wordlist[0][j:i]
+            i += 1
+            d = {}
+    except IndexError:
+        return wordlist[0][j:i]
+    return ""
+
+
+STRIPCOLOR_REGEX = re.compile(r"\x1B\[([0-9]{1,3}(;[0-9]{1,2})?)?[m|K]")
+
+def stripcolor(s: str) -> str:
+    return STRIPCOLOR_REGEX.sub('', s)
+
+
+def real_len(s: str) -> int:
+    return len(stripcolor(s))
+
+
+def left_align(s: str, maxlen: int) -> str:
+    stripped = stripcolor(s)
+    if len(stripped) > maxlen:
+        # too bad, we remove the color
+        return stripped[:maxlen]
+    padding = maxlen - len(stripped)
+    return s + ' '*padding
+
+
+def build_menu(
+        cons: console.Console,
+        wordlist: list[str],
+        start: int,
+        use_brackets: bool,
+        sort_in_column: bool,
+) -> tuple[list[str], int]:
+    if use_brackets:
+        item = "[ %s ]"
+        padding = 4
+    else:
+        item = "%s  "
+        padding = 2
+    maxlen = min(max(map(real_len, wordlist)), cons.width - padding)
+    cols = int(cons.width / (maxlen + padding))
+    rows = int((len(wordlist) - 1)/cols + 1)
+
+    if sort_in_column:
+        # sort_in_column=False (default)     sort_in_column=True
+        #          A B C                       A D G
+        #          D E F                       B E
+        #          G                           C F
+        #
+        # "fill" the table with empty words, so we always have the same amout
+        # of rows for each column
+        missing = cols*rows - len(wordlist)
+        wordlist = wordlist + ['']*missing
+        indexes = [(i % cols) * rows + i // cols for i in range(len(wordlist))]
+        wordlist = [wordlist[i] for i in indexes]
+    menu = []
+    i = start
+    for r in range(rows):
+        row = []
+        for col in range(cols):
+            row.append(item % left_align(wordlist[i], maxlen))
+            i += 1
+            if i >= len(wordlist):
+                break
+        menu.append(''.join(row))
+        if i >= len(wordlist):
+            i = 0
+            break
+        if r + 5 > cons.height:
+            menu.append("   %d more... " % (len(wordlist) - i))
+            break
+    return menu, i
+
+# this gets somewhat user interface-y, and as a result the logic gets
+# very convoluted.
+#
+#  To summarise the summary of the summary:- people are a problem.
+#                  -- The Hitch-Hikers Guide to the Galaxy, Episode 12
+
+#### Desired behaviour of the completions commands.
+# the considerations are:
+# (1) how many completions are possible
+# (2) whether the last command was a completion
+# (3) if we can assume that the completer is going to return the same set of
+#     completions: this is controlled by the ``assume_immutable_completions``
+#     variable on the reader, which is True by default to match the historical
+#     behaviour of pyrepl, but e.g. False in the ReadlineAlikeReader to match
+#     more closely readline's semantics (this is needed e.g. by
+#     fancycompleter)
+#
+# if there's no possible completion, beep at the user and point this out.
+# this is easy.
+#
+# if there's only one possible completion, stick it in.  if the last thing
+# user did was a completion, point out that he isn't getting anywhere, but
+# only if the ``assume_immutable_completions`` is True.
+#
+# now it gets complicated.
+#
+# for the first press of a completion key:
+#  if there's a common prefix, stick it in.
+
+#  irrespective of whether anything got stuck in, if the word is now
+#  complete, show the "complete but not unique" message
+
+#  if there's no common prefix and if the word is not now complete,
+#  beep.
+
+#        common prefix ->    yes          no
+#        word complete \/
+#            yes           "cbnu"      "cbnu"
+#            no              -          beep
+
+# for the second bang on the completion key
+#  there will necessarily be no common prefix
+#  show a menu of the choices.
+
+# for subsequent bangs, rotate the menu around (if there are sufficient
+# choices).
+
+
+class complete(commands.Command):
+    def do(self) -> None:
+        r: CompletingReader
+        r = self.reader  # type: ignore[assignment]
+        last_is_completer = r.last_command_is(self.__class__)
+        immutable_completions = r.assume_immutable_completions
+        completions_unchangable = last_is_completer and immutable_completions
+        stem = r.get_stem()
+        if not completions_unchangable:
+            r.cmpltn_menu_choices = r.get_completions(stem)
+
+        completions = r.cmpltn_menu_choices
+        if not completions:
+            r.error("no matches")
+        elif len(completions) == 1:
+            if completions_unchangable and len(completions[0]) == len(stem):
+                r.msg = "[ sole completion ]"
+                r.dirty = True
+            r.insert(completions[0][len(stem):])
+        else:
+            p = prefix(completions, len(stem))
+            if p:
+                r.insert(p)
+            if last_is_completer:
+                r.cmpltn_menu_visible = True
+                r.cmpltn_message_visible = False
+                r.cmpltn_menu, r.cmpltn_menu_end = build_menu(
+                    r.console, completions, r.cmpltn_menu_end,
+                    r.use_brackets, r.sort_in_column)
+                r.dirty = True
+            elif not r.cmpltn_menu_visible:
+                r.cmpltn_message_visible = True
+                if stem + p in completions:
+                    r.msg = "[ complete but not unique ]"
+                    r.dirty = True
+                else:
+                    r.msg = "[ not unique ]"
+                    r.dirty = True
+
+
+class self_insert(commands.self_insert):
+    def do(self) -> None:
+        r: CompletingReader
+        r = self.reader  # type: ignore[assignment]
+
+        commands.self_insert.do(self)
+        if r.cmpltn_menu_visible:
+            stem = r.get_stem()
+            if len(stem) < 1:
+                r.cmpltn_reset()
+            else:
+                completions = [w for w in r.cmpltn_menu_choices
+                               if w.startswith(stem)]
+                if completions:
+                    r.cmpltn_menu, r.cmpltn_menu_end = build_menu(
+                        r.console, completions, 0,
+                        r.use_brackets, r.sort_in_column)
+                else:
+                    r.cmpltn_reset()
+
+
+@dataclass
+class CompletingReader(Reader):
+    """Adds completion support"""
+
+    ### Class variables
+    # see the comment for the complete command
+    assume_immutable_completions = True
+    use_brackets = True  # display completions inside []
+    sort_in_column = False
+
+    ### Instance variables
+    cmpltn_menu: list[str] = field(init=False)
+    cmpltn_menu_visible: bool = field(init=False)
+    cmpltn_message_visible: bool = field(init=False)
+    cmpltn_menu_end: int = field(init=False)
+    cmpltn_menu_choices: list[str] = field(init=False)
+
+    def __post_init__(self) -> None:
+        super().__post_init__()
+        self.cmpltn_reset()
+        for c in (complete, self_insert):
+            self.commands[c.__name__] = c
+            self.commands[c.__name__.replace('_', '-')] = c
+
+    def collect_keymap(self) -> tuple[tuple[KeySpec, CommandName], ...]:
+        return super().collect_keymap() + (
+            (r'\t', 'complete'),)
+
+    def after_command(self, cmd: Command) -> None:
+        super().after_command(cmd)
+        if not isinstance(cmd, (complete, self_insert)):
+            self.cmpltn_reset()
+
+    def calc_screen(self) -> list[str]:
+        screen = super().calc_screen()
+        if self.cmpltn_menu_visible:
+            # We display the completions menu below the current prompt
+            ly = self.lxy[1] + 1
+            screen[ly:ly] = self.cmpltn_menu
+            # If we're not in the middle of multiline edit, don't append to screeninfo
+            # since that screws up the position calculation in pos2xy function.
+            # This is a hack to prevent the cursor jumping
+            # into the completions menu when pressing left or down arrow.
+            if self.pos != len(self.buffer):
+                self.screeninfo[ly:ly] = [(0, [])]*len(self.cmpltn_menu)
+        return screen
+
+    def finish(self) -> None:
+        super().finish()
+        self.cmpltn_reset()
+
+    def cmpltn_reset(self) -> None:
+        self.cmpltn_menu = []
+        self.cmpltn_menu_visible = False
+        self.cmpltn_message_visible = False
+        self.cmpltn_menu_end = 0
+        self.cmpltn_menu_choices = []
+
+    def get_stem(self) -> str:
+        st = self.syntax_table
+        SW = reader.SYNTAX_WORD
+        b = self.buffer
+        p = self.pos - 1
+        while p >= 0 and st.get(b[p], SW) == SW:
+            p -= 1
+        return ''.join(b[p+1:self.pos])
+
+    def get_completions(self, stem: str) -> list[str]:
+        return []
--- a/Lib/_pyrepl/console.py
+++ b/Lib/_pyrepl/console.py
@@ -0,0 +1,213 @@
+#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from __future__ import annotations
+
+import _colorize  # type: ignore[import-not-found]
+
+from abc import ABC, abstractmethod
+import ast
+import code
+from dataclasses import dataclass, field
+import os.path
+import sys
+
+
+TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import IO
+    from typing import Callable
+
+
+@dataclass
+class Event:
+    evt: str
+    data: str
+    raw: bytes = b""
+
+
+@dataclass
+class Console(ABC):
+    posxy: tuple[int, int]
+    screen: list[str] = field(default_factory=list)
+    height: int = 25
+    width: int = 80
+
+    def __init__(
+        self,
+        f_in: IO[bytes] | int = 0,
+        f_out: IO[bytes] | int = 1,
+        term: str = "",
+        encoding: str = "",
+    ):
+        self.encoding = encoding or sys.getdefaultencoding()
+
+        if isinstance(f_in, int):
+            self.input_fd = f_in
+        else:
+            self.input_fd = f_in.fileno()
+
+        if isinstance(f_out, int):
+            self.output_fd = f_out
+        else:
+            self.output_fd = f_out.fileno()
+
+    @abstractmethod
+    def refresh(self, screen: list[str], xy: tuple[int, int]) -> None: ...
+
+    @abstractmethod
+    def prepare(self) -> None: ...
+
+    @abstractmethod
+    def restore(self) -> None: ...
+
+    @abstractmethod
+    def move_cursor(self, x: int, y: int) -> None: ...
+
+    @abstractmethod
+    def set_cursor_vis(self, visible: bool) -> None: ...
+
+    @abstractmethod
+    def getheightwidth(self) -> tuple[int, int]:
+        """Return (height, width) where height and width are the height
+        and width of the terminal window in characters."""
+        ...
+
+    @abstractmethod
+    def get_event(self, block: bool = True) -> Event | None:
+        """Return an Event instance.  Returns None if |block| is false
+        and there is no event pending, otherwise waits for the
+        completion of an event."""
+        ...
+
+    @abstractmethod
+    def push_char(self, char: int | bytes) -> None:
+        """
+        Push a character to the console event queue.
+        """
+        ...
+
+    @abstractmethod
+    def beep(self) -> None: ...
+
+    @abstractmethod
+    def clear(self) -> None:
+        """Wipe the screen"""
+        ...
+
+    @abstractmethod
+    def finish(self) -> None:
+        """Move the cursor to the end of the display and otherwise get
+        ready for end.  XXX could be merged with restore?  Hmm."""
+        ...
+
+    @abstractmethod
+    def flushoutput(self) -> None:
+        """Flush all output to the screen (assuming there's some
+        buffering going on somewhere)."""
+        ...
+
+    @abstractmethod
+    def forgetinput(self) -> None:
+        """Forget all pending, but not yet processed input."""
+        ...
+
+    @abstractmethod
+    def getpending(self) -> Event:
+        """Return the characters that have been typed but not yet
+        processed."""
+        ...
+
+    @abstractmethod
+    def wait(self, timeout: float | None) -> bool:
+        """Wait for an event. The return value is True if an event is
+        available, False if the timeout has been reached. If timeout is
+        None, wait forever. The timeout is in milliseconds."""
+        ...
+
+    @property
+    def input_hook(self) -> Callable[[], int] | None:
+        """Returns the current input hook."""
+        ...
+
+    @abstractmethod
+    def repaint(self) -> None: ...
+
+
+class InteractiveColoredConsole(code.InteractiveConsole):
+    def __init__(
+        self,
+        locals: dict[str, object] | None = None,
+        filename: str = "<console>",
+        *,
+        local_exit: bool = False,
+    ) -> None:
+        super().__init__(locals=locals, filename=filename, local_exit=local_exit)  # type: ignore[call-arg]
+        self.can_colorize = _colorize.can_colorize()
+
+    def showsyntaxerror(self, filename=None, **kwargs):
+        super().showsyntaxerror(filename=filename, **kwargs)
+
+    def _excepthook(self, typ, value, tb):
+        import traceback
+        lines = traceback.format_exception(
+                typ, value, tb,
+                colorize=self.can_colorize,
+                limit=traceback.BUILTIN_EXCEPTION_LIMIT)
+        self.write(''.join(lines))
+
+    def runsource(self, source, filename="<input>", symbol="single"):
+        try:
+            tree = self.compile.compiler(
+                source,
+                filename,
+                "exec",
+                ast.PyCF_ONLY_AST,
+                incomplete_input=False,
+            )
+        except (SyntaxError, OverflowError, ValueError):
+            self.showsyntaxerror(filename, source=source)
+            return False
+        if tree.body:
+            *_, last_stmt = tree.body
+        for stmt in tree.body:
+            wrapper = ast.Interactive if stmt is last_stmt else ast.Module
+            the_symbol = symbol if stmt is last_stmt else "exec"
+            item = wrapper([stmt])
+            try:
+                code = self.compile.compiler(item, filename, the_symbol)
+            except SyntaxError as e:
+                if e.args[0] == "'await' outside function":
+                    python = os.path.basename(sys.executable)
+                    e.add_note(
+                        f"Try the asyncio REPL ({python} -m asyncio) to use"
+                        f" top-level 'await' and run background asyncio tasks."
+                    )
+                self.showsyntaxerror(filename, source=source)
+                return False
+            except (OverflowError, ValueError):
+                self.showsyntaxerror(filename, source=source)
+                return False
+
+            if code is None:
+                return True
+
+            self.runcode(code)
+        return False
--- a/Lib/_pyrepl/curses.py
+++ b/Lib/_pyrepl/curses.py
@@ -0,0 +1,33 @@
+#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+
+try:
+    import _curses
+except ImportError:
+    try:
+        import curses as _curses  # type: ignore[no-redef]
+    except ImportError:
+        from . import _minimal_curses as _curses  # type: ignore[no-redef]
+
+setupterm = _curses.setupterm
+tigetstr = _curses.tigetstr
+tparm = _curses.tparm
+error = _curses.error
--- a/Lib/_pyrepl/fancy_termios.py
+++ b/Lib/_pyrepl/fancy_termios.py
@@ -0,0 +1,76 @@
+#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+import termios
+
+
+class TermState:
+    def __init__(self, tuples):
+        (
+            self.iflag,
+            self.oflag,
+            self.cflag,
+            self.lflag,
+            self.ispeed,
+            self.ospeed,
+            self.cc,
+        ) = tuples
+
+    def as_list(self):
+        return [
+            self.iflag,
+            self.oflag,
+            self.cflag,
+            self.lflag,
+            self.ispeed,
+            self.ospeed,
+            # Always return a copy of the control characters list to ensure
+            # there are not any additional references to self.cc
+            self.cc[:],
+        ]
+
+    def copy(self):
+        return self.__class__(self.as_list())
+
+
+def tcgetattr(fd):
+    return TermState(termios.tcgetattr(fd))
+
+
+def tcsetattr(fd, when, attrs):
+    termios.tcsetattr(fd, when, attrs.as_list())
+
+
+class Term(TermState):
+    TS__init__ = TermState.__init__
+
+    def __init__(self, fd=0):
+        self.TS__init__(termios.tcgetattr(fd))
+        self.fd = fd
+        self.stack = []
+
+    def save(self):
+        self.stack.append(self.as_list())
+
+    def set(self, when=termios.TCSANOW):
+        termios.tcsetattr(self.fd, when, self.as_list())
+
+    def restore(self):
+        self.TS__init__(self.stack.pop())
+        self.set()
--- a/Lib/_pyrepl/historical_reader.py
+++ b/Lib/_pyrepl/historical_reader.py
@@ -0,0 +1,419 @@
+#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from __future__ import annotations
+
+from contextlib import contextmanager
+from dataclasses import dataclass, field
+
+from . import commands, input
+from .reader import Reader
+
+
+if False:
+    from .types import SimpleContextManager, KeySpec, CommandName
+
+
+isearch_keymap: tuple[tuple[KeySpec, CommandName], ...] = tuple(
+    [("\\%03o" % c, "isearch-end") for c in range(256) if chr(c) != "\\"]
+    + [(c, "isearch-add-character") for c in map(chr, range(32, 127)) if c != "\\"]
+    + [
+        ("\\%03o" % c, "isearch-add-character")
+        for c in range(256)
+        if chr(c).isalpha() and chr(c) != "\\"
+    ]
+    + [
+        ("\\\\", "self-insert"),
+        (r"\C-r", "isearch-backwards"),
+        (r"\C-s", "isearch-forwards"),
+        (r"\C-c", "isearch-cancel"),
+        (r"\C-g", "isearch-cancel"),
+        (r"\<backspace>", "isearch-backspace"),
+    ]
+)
+
+ISEARCH_DIRECTION_NONE = ""
+ISEARCH_DIRECTION_BACKWARDS = "r"
+ISEARCH_DIRECTION_FORWARDS = "f"
+
+
+class next_history(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        if r.historyi == len(r.history):
+            r.error("end of history list")
+            return
+        r.select_item(r.historyi + 1)
+
+
+class previous_history(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        if r.historyi == 0:
+            r.error("start of history list")
+            return
+        r.select_item(r.historyi - 1)
+
+
+class history_search_backward(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.search_next(forwards=False)
+
+
+class history_search_forward(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.search_next(forwards=True)
+
+
+class restore_history(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        if r.historyi != len(r.history):
+            if r.get_unicode() != r.history[r.historyi]:
+                r.buffer = list(r.history[r.historyi])
+                r.pos = len(r.buffer)
+                r.dirty = True
+
+
+class first_history(commands.Command):
+    def do(self) -> None:
+        self.reader.select_item(0)
+
+
+class last_history(commands.Command):
+    def do(self) -> None:
+        self.reader.select_item(len(self.reader.history))
+
+
+class operate_and_get_next(commands.FinishCommand):
+    def do(self) -> None:
+        self.reader.next_history = self.reader.historyi + 1
+
+
+class yank_arg(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        if r.last_command is self.__class__:
+            r.yank_arg_i += 1
+        else:
+            r.yank_arg_i = 0
+        if r.historyi < r.yank_arg_i:
+            r.error("beginning of history list")
+            return
+        a = r.get_arg(-1)
+        # XXX how to split?
+        words = r.get_item(r.historyi - r.yank_arg_i - 1).split()
+        if a < -len(words) or a >= len(words):
+            r.error("no such arg")
+            return
+        w = words[a]
+        b = r.buffer
+        if r.yank_arg_i > 0:
+            o = len(r.yank_arg_yanked)
+        else:
+            o = 0
+        b[r.pos - o : r.pos] = list(w)
+        r.yank_arg_yanked = w
+        r.pos += len(w) - o
+        r.dirty = True
+
+
+class forward_history_isearch(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_FORWARDS
+        r.isearch_start = r.historyi, r.pos
+        r.isearch_term = ""
+        r.dirty = True
+        r.push_input_trans(r.isearch_trans)
+
+
+class reverse_history_isearch(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_BACKWARDS
+        r.dirty = True
+        r.isearch_term = ""
+        r.push_input_trans(r.isearch_trans)
+        r.isearch_start = r.historyi, r.pos
+
+
+class isearch_cancel(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_NONE
+        r.pop_input_trans()
+        r.select_item(r.isearch_start[0])
+        r.pos = r.isearch_start[1]
+        r.dirty = True
+
+
+class isearch_add_character(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        r.isearch_term += self.event[-1]
+        r.dirty = True
+        p = r.pos + len(r.isearch_term) - 1
+        if b[p : p + 1] != [r.isearch_term[-1]]:
+            r.isearch_next()
+
+
+class isearch_backspace(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        if len(r.isearch_term) > 0:
+            r.isearch_term = r.isearch_term[:-1]
+            r.dirty = True
+        else:
+            r.error("nothing to rubout")
+
+
+class isearch_forwards(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_FORWARDS
+        r.isearch_next()
+
+
+class isearch_backwards(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_BACKWARDS
+        r.isearch_next()
+
+
+class isearch_end(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        r.isearch_direction = ISEARCH_DIRECTION_NONE
+        r.console.forgetinput()
+        r.pop_input_trans()
+        r.dirty = True
+
+
+@dataclass
+class HistoricalReader(Reader):
+    """Adds history support (with incremental history searching) to the
+    Reader class.
+    """
+
+    history: list[str] = field(default_factory=list)
+    historyi: int = 0
+    next_history: int | None = None
+    transient_history: dict[int, str] = field(default_factory=dict)
+    isearch_term: str = ""
+    isearch_direction: str = ISEARCH_DIRECTION_NONE
+    isearch_start: tuple[int, int] = field(init=False)
+    isearch_trans: input.KeymapTranslator = field(init=False)
+    yank_arg_i: int = 0
+    yank_arg_yanked: str = ""
+
+    def __post_init__(self) -> None:
+        super().__post_init__()
+        for c in [
+            next_history,
+            previous_history,
+            restore_history,
+            first_history,
+            last_history,
+            yank_arg,
+            forward_history_isearch,
+            reverse_history_isearch,
+            isearch_end,
+            isearch_add_character,
+            isearch_cancel,
+            isearch_add_character,
+            isearch_backspace,
+            isearch_forwards,
+            isearch_backwards,
+            operate_and_get_next,
+            history_search_backward,
+            history_search_forward,
+        ]:
+            self.commands[c.__name__] = c
+            self.commands[c.__name__.replace("_", "-")] = c
+        self.isearch_start = self.historyi, self.pos
+        self.isearch_trans = input.KeymapTranslator(
+            isearch_keymap, invalid_cls=isearch_end, character_cls=isearch_add_character
+        )
+
+    def collect_keymap(self) -> tuple[tuple[KeySpec, CommandName], ...]:
+        return super().collect_keymap() + (
+            (r"\C-n", "next-history"),
+            (r"\C-p", "previous-history"),
+            (r"\C-o", "operate-and-get-next"),
+            (r"\C-r", "reverse-history-isearch"),
+            (r"\C-s", "forward-history-isearch"),
+            (r"\M-r", "restore-history"),
+            (r"\M-.", "yank-arg"),
+            (r"\<page down>", "history-search-forward"),
+            (r"\x1b[6~", "history-search-forward"),
+            (r"\<page up>", "history-search-backward"),
+            (r"\x1b[5~", "history-search-backward"),
+        )
+
+    def select_item(self, i: int) -> None:
+        self.transient_history[self.historyi] = self.get_unicode()
+        buf = self.transient_history.get(i)
+        if buf is None:
+            buf = self.history[i].rstrip()
+        self.buffer = list(buf)
+        self.historyi = i
+        self.pos = len(self.buffer)
+        self.dirty = True
+        self.last_refresh_cache.invalidated = True
+
+    def get_item(self, i: int) -> str:
+        if i != len(self.history):
+            return self.transient_history.get(i, self.history[i])
+        else:
+            return self.transient_history.get(i, self.get_unicode())
+
+    @contextmanager
+    def suspend(self) -> SimpleContextManager:
+        with super().suspend(), self.suspend_history():
+            yield
+
+    @contextmanager
+    def suspend_history(self) -> SimpleContextManager:
+        try:
+            old_history = self.history[:]
+            del self.history[:]
+            yield
+        finally:
+            self.history[:] = old_history
+
+    def prepare(self) -> None:
+        super().prepare()
+        try:
+            self.transient_history = {}
+            if self.next_history is not None and self.next_history < len(self.history):
+                self.historyi = self.next_history
+                self.buffer[:] = list(self.history[self.next_history])
+                self.pos = len(self.buffer)
+                self.transient_history[len(self.history)] = ""
+            else:
+                self.historyi = len(self.history)
+            self.next_history = None
+        except:
+            self.restore()
+            raise
+
+    def get_prompt(self, lineno: int, cursor_on_line: bool) -> str:
+        if cursor_on_line and self.isearch_direction != ISEARCH_DIRECTION_NONE:
+            d = "rf"[self.isearch_direction == ISEARCH_DIRECTION_FORWARDS]
+            return "(%s-search `%s') " % (d, self.isearch_term)
+        else:
+            return super().get_prompt(lineno, cursor_on_line)
+
+    def search_next(self, *, forwards: bool) -> None:
+        """Search history for the current line contents up to the cursor.
+
+        Selects the first item found. If nothing is under the cursor, any next
+        item in history is selected.
+        """
+        pos = self.pos
+        s = self.get_unicode()
+        history_index = self.historyi
+
+        # In multiline contexts, we're only interested in the current line.
+        nl_index = s.rfind('\n', 0, pos)
+        prefix = s[nl_index + 1:pos]
+        pos = len(prefix)
+
+        match_prefix = len(prefix)
+        len_item = 0
+        if history_index < len(self.history):
+            len_item = len(self.get_item(history_index))
+        if len_item and pos == len_item:
+            match_prefix = False
+        elif not pos:
+            match_prefix = False
+
+        while 1:
+            if forwards:
+                out_of_bounds = history_index >= len(self.history) - 1
+            else:
+                out_of_bounds = history_index == 0
+            if out_of_bounds:
+                if forwards and not match_prefix:
+                    self.pos = 0
+                    self.buffer = []
+                    self.dirty = True
+                else:
+                    self.error("not found")
+                return
+
+            history_index += 1 if forwards else -1
+            s = self.get_item(history_index)
+
+            if not match_prefix:
+                self.select_item(history_index)
+                return
+
+            len_acc = 0
+            for i, line in enumerate(s.splitlines(keepends=True)):
+                if line.startswith(prefix):
+                    self.select_item(history_index)
+                    self.pos = pos + len_acc
+                    return
+                len_acc += len(line)
+
+    def isearch_next(self) -> None:
+        st = self.isearch_term
+        p = self.pos
+        i = self.historyi
+        s = self.get_unicode()
+        forwards = self.isearch_direction == ISEARCH_DIRECTION_FORWARDS
+        while 1:
+            if forwards:
+                p = s.find(st, p + 1)
+            else:
+                p = s.rfind(st, 0, p + len(st) - 1)
+            if p != -1:
+                self.select_item(i)
+                self.pos = p
+                return
+            elif (forwards and i >= len(self.history) - 1) or (not forwards and i == 0):
+                self.error("not found")
+                return
+            else:
+                if forwards:
+                    i += 1
+                    s = self.get_item(i)
+                    p = -1
+                else:
+                    i -= 1
+                    s = self.get_item(i)
+                    p = len(s)
+
+    def finish(self) -> None:
+        super().finish()
+        ret = self.get_unicode()
+        for i, t in self.transient_history.items():
+            if i < len(self.history) and i != self.historyi:
+                self.history[i] = t
+        if ret and should_auto_add_history:
+            self.history.append(ret)
+
+
+should_auto_add_history = True
--- a/Lib/_pyrepl/input.py
+++ b/Lib/_pyrepl/input.py
@@ -0,0 +1,114 @@
+#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# (naming modules after builtin functions is not such a hot idea...)
+
+# an KeyTrans instance translates Event objects into Command objects
+
+# hmm, at what level do we want [C-i] and [tab] to be equivalent?
+# [meta-a] and [esc a]?  obviously, these are going to be equivalent
+# for the UnixConsole, but should they be for PygameConsole?
+
+# it would in any situation seem to be a bad idea to bind, say, [tab]
+# and [C-i] to *different* things... but should binding one bind the
+# other?
+
+# executive, temporary decision: [tab] and [C-i] are distinct, but
+# [meta-key] is identified with [esc key].  We demand that any console
+# class does quite a lot towards emulating a unix terminal.
+
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+import unicodedata
+from collections import deque
+
+
+# types
+if False:
+    from .types import EventTuple
+
+
+class InputTranslator(ABC):
+    @abstractmethod
+    def push(self, evt: EventTuple) -> None:
+        pass
+
+    @abstractmethod
+    def get(self) -> EventTuple | None:
+        return None
+
+    @abstractmethod
+    def empty(self) -> bool:
+        return True
+
+
+class KeymapTranslator(InputTranslator):
+    def __init__(self, keymap, verbose=False, invalid_cls=None, character_cls=None):
+        self.verbose = verbose
+        from .keymap import compile_keymap, parse_keys
+
+        self.keymap = keymap
+        self.invalid_cls = invalid_cls
+        self.character_cls = character_cls
+        d = {}
+        for keyspec, command in keymap:
+            keyseq = tuple(parse_keys(keyspec))
+            d[keyseq] = command
+        if self.verbose:
+            print(d)
+        self.k = self.ck = compile_keymap(d, ())
+        self.results = deque()
+        self.stack = []
+
+    def push(self, evt):
+        if self.verbose:
+            print("pushed", evt.data, end="")
+        key = evt.data
+        d = self.k.get(key)
+        if isinstance(d, dict):
+            if self.verbose:
+                print("transition")
+            self.stack.append(key)
+            self.k = d
+        else:
+            if d is None:
+                if self.verbose:
+                    print("invalid")
+                if self.stack or len(key) > 1 or unicodedata.category(key) == "C":
+                    self.results.append((self.invalid_cls, self.stack + [key]))
+                else:
+                    # small optimization:
+                    self.k[key] = self.character_cls
+                    self.results.append((self.character_cls, [key]))
+            else:
+                if self.verbose:
+                    print("matched", d)
+                self.results.append((d, self.stack + [key]))
+            self.stack = []
+            self.k = self.ck
+
+    def get(self):
+        if self.results:
+            return self.results.popleft()
+        else:
+            return None
+
+    def empty(self) -> bool:
+        return not self.results
--- a/Lib/_pyrepl/keymap.py
+++ b/Lib/_pyrepl/keymap.py
@@ -0,0 +1,213 @@
+#   Copyright 2000-2008 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""
+Keymap contains functions for parsing keyspecs and turning keyspecs into
+appropriate sequences.
+
+A keyspec is a string representing a sequence of key presses that can
+be bound to a command. All characters other than the backslash represent
+themselves. In the traditional manner, a backslash introduces an escape
+sequence.
+
+pyrepl uses its own keyspec format that is meant to be a strict superset of
+readline's KEYSEQ format. This means that if a spec is found that readline
+accepts that this doesn't, it should be logged as a bug. Note that this means
+we're using the `\\C-o' style of readline's keyspec, not the `Control-o' sort.
+
+The extension to readline is that the sequence \\<KEY> denotes the
+sequence of characters produced by hitting KEY.
+
+Examples:
+`a'      - what you get when you hit the `a' key
+`\\EOA'  - Escape - O - A (up, on my terminal)
+`\\<UP>' - the up arrow key
+`\\<up>' - ditto (keynames are case-insensitive)
+`\\C-o', `\\c-o'  - control-o
+`\\M-.'  - meta-period
+`\\E.'   - ditto (that's how meta works for pyrepl)
+`\\<tab>', `\\<TAB>', `\\t', `\\011', '\\x09', '\\X09', '\\C-i', '\\C-I'
+   - all of these are the tab character.
+"""
+
+_escapes = {
+    "\\": "\\",
+    "'": "'",
+    '"': '"',
+    "a": "\a",
+    "b": "\b",
+    "e": "\033",
+    "f": "\f",
+    "n": "\n",
+    "r": "\r",
+    "t": "\t",
+    "v": "\v",
+}
+
+_keynames = {
+    "backspace": "backspace",
+    "delete": "delete",
+    "down": "down",
+    "end": "end",
+    "enter": "\r",
+    "escape": "\033",
+    "f1": "f1",
+    "f2": "f2",
+    "f3": "f3",
+    "f4": "f4",
+    "f5": "f5",
+    "f6": "f6",
+    "f7": "f7",
+    "f8": "f8",
+    "f9": "f9",
+    "f10": "f10",
+    "f11": "f11",
+    "f12": "f12",
+    "f13": "f13",
+    "f14": "f14",
+    "f15": "f15",
+    "f16": "f16",
+    "f17": "f17",
+    "f18": "f18",
+    "f19": "f19",
+    "f20": "f20",
+    "home": "home",
+    "insert": "insert",
+    "left": "left",
+    "page down": "page down",
+    "page up": "page up",
+    "return": "\r",
+    "right": "right",
+    "space": " ",
+    "tab": "\t",
+    "up": "up",
+}
+
+
+class KeySpecError(Exception):
+    pass
+
+
+def parse_keys(keys: str) -> list[str]:
+    """Parse keys in keyspec format to a sequence of keys."""
+    s = 0
+    r: list[str] = []
+    while s < len(keys):
+        k, s = _parse_single_key_sequence(keys, s)
+        r.extend(k)
+    return r
+
+
+def _parse_single_key_sequence(key: str, s: int) -> tuple[list[str], int]:
+    ctrl = 0
+    meta = 0
+    ret = ""
+    while not ret and s < len(key):
+        if key[s] == "\\":
+            c = key[s + 1].lower()
+            if c in _escapes:
+                ret = _escapes[c]
+                s += 2
+            elif c == "c":
+                if key[s + 2] != "-":
+                    raise KeySpecError(
+                        "\\C must be followed by `-' (char %d of %s)"
+                        % (s + 2, repr(key))
+                    )
+                if ctrl:
+                    raise KeySpecError(
+                        "doubled \\C- (char %d of %s)" % (s + 1, repr(key))
+                    )
+                ctrl = 1
+                s += 3
+            elif c == "m":
+                if key[s + 2] != "-":
+                    raise KeySpecError(
+                        "\\M must be followed by `-' (char %d of %s)"
+                        % (s + 2, repr(key))
+                    )
+                if meta:
+                    raise KeySpecError(
+                        "doubled \\M- (char %d of %s)" % (s + 1, repr(key))
+                    )
+                meta = 1
+                s += 3
+            elif c.isdigit():
+                n = key[s + 1 : s + 4]
+                ret = chr(int(n, 8))
+                s += 4
+            elif c == "x":
+                n = key[s + 2 : s + 4]
+                ret = chr(int(n, 16))
+                s += 4
+            elif c == "<":
+                t = key.find(">", s)
+                if t == -1:
+                    raise KeySpecError(
+                        "unterminated \\< starting at char %d of %s"
+                        % (s + 1, repr(key))
+                    )
+                ret = key[s + 2 : t].lower()
+                if ret not in _keynames:
+                    raise KeySpecError(
+                        "unrecognised keyname `%s' at char %d of %s"
+                        % (ret, s + 2, repr(key))
+                    )
+                ret = _keynames[ret]
+                s = t + 1
+            else:
+                raise KeySpecError(
+                    "unknown backslash escape %s at char %d of %s"
+                    % (repr(c), s + 2, repr(key))
+                )
+        else:
+            ret = key[s]
+            s += 1
+    if ctrl:
+        if len(ret) == 1:
+            ret = chr(ord(ret) & 0x1F)  # curses.ascii.ctrl()
+        elif ret in {"left", "right"}:
+            ret = f"ctrl {ret}"
+        else:
+            raise KeySpecError("\\C- followed by invalid key")
+
+    result = [ret], s
+    if meta:
+        result[0].insert(0, "\033")
+    return result
+
+
+def compile_keymap(keymap, empty=b""):
+    r = {}
+    for key, value in keymap.items():
+        if isinstance(key, bytes):
+            first = key[:1]
+        else:
+            first = key[0]
+        r.setdefault(first, {})[key[1:]] = value
+    for key, value in r.items():
+        if empty in value:
+            if len(value) != 1:
+                raise KeySpecError("key definitions for %s clash" % (value.values(),))
+            else:
+                r[key] = value[empty]
+        else:
+            r[key] = compile_keymap(value, empty)
+    return r
--- a/Lib/_pyrepl/main.py
+++ b/Lib/_pyrepl/main.py
@@ -0,0 +1,59 @@
+import errno
+import os
+import sys
+
+
+CAN_USE_PYREPL: bool
+FAIL_REASON: str
+try:
+    if sys.platform == "win32" and sys.getwindowsversion().build < 10586:
+        raise RuntimeError("Windows 10 TH2 or later required")
+    if not os.isatty(sys.stdin.fileno()):
+        raise OSError(errno.ENOTTY, "tty required", "stdin")
+    from .simple_interact import check
+    if err := check():
+        raise RuntimeError(err)
+except Exception as e:
+    CAN_USE_PYREPL = False
+    FAIL_REASON = f"warning: can't use pyrepl: {e}"
+else:
+    CAN_USE_PYREPL = True
+    FAIL_REASON = ""
+
+
+def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):
+    if not CAN_USE_PYREPL:
+        if not os.getenv('PYTHON_BASIC_REPL') and FAIL_REASON:
+            from .trace import trace
+            trace(FAIL_REASON)
+            print(FAIL_REASON, file=sys.stderr)
+        return sys._baserepl()
+
+    if mainmodule:
+        namespace = mainmodule.__dict__
+    else:
+        import __main__
+        namespace = __main__.__dict__
+        namespace.pop("__pyrepl_interactive_console", None)
+
+    # sys._baserepl() above does this internally, we do it here
+    startup_path = os.getenv("PYTHONSTARTUP")
+    if pythonstartup and startup_path:
+        sys.audit("cpython.run_startup", startup_path)
+
+        import tokenize
+        with tokenize.open(startup_path) as f:
+            startup_code = compile(f.read(), startup_path, "exec")
+            exec(startup_code, namespace)
+
+    # set sys.{ps1,ps2} just before invoking the interactive interpreter. This
+    # mimics what CPython does in pythonrun.c
+    if not hasattr(sys, "ps1"):
+        sys.ps1 = ">>> "
+    if not hasattr(sys, "ps2"):
+        sys.ps2 = "... "
+
+    from .console import InteractiveColoredConsole
+    from .simple_interact import run_multiline_interactive_console
+    console = InteractiveColoredConsole(namespace, filename="<stdin>")
+    run_multiline_interactive_console(console)
--- a/Lib/_pyrepl/mypy.ini
+++ b/Lib/_pyrepl/mypy.ini
@@ -0,0 +1,24 @@
+# Config file for running mypy on _pyrepl.
+# Run mypy by invoking `mypy --config-file Lib/_pyrepl/mypy.ini`
+# on the command-line from the repo root
+
+[mypy]
+files = Lib/_pyrepl
+explicit_package_bases = True
+python_version = 3.12
+platform = linux
+pretty = True
+
+# Enable most stricter settings
+enable_error_code = ignore-without-code,redundant-expr
+strict = True
+
+# Various stricter settings that we can't yet enable
+# Try to enable these in the following order:
+disallow_untyped_calls = False
+disallow_untyped_defs = False
+check_untyped_defs = False
+
+# Various internal modules that typeshed deliberately doesn't have stubs for:
+[mypy-_abc.*,_opcode.*,_overlapped.*,_testcapi.*,_testinternalcapi.*,test.*]
+ignore_missing_imports = True
--- a/Lib/_pyrepl/pager.py
+++ b/Lib/_pyrepl/pager.py
@@ -0,0 +1,175 @@
+from __future__ import annotations
+
+import io
+import os
+import re
+import sys
+
+
+# types
+if False:
+    from typing import Protocol
+    class Pager(Protocol):
+        def __call__(self, text: str, title: str = "") -> None:
+            ...
+
+
+def get_pager() -> Pager:
+    """Decide what method to use for paging through text."""
+    if not hasattr(sys.stdin, "isatty"):
+        return plain_pager
+    if not hasattr(sys.stdout, "isatty"):
+        return plain_pager
+    if not sys.stdin.isatty() or not sys.stdout.isatty():
+        return plain_pager
+    if sys.platform == "emscripten":
+        return plain_pager
+    use_pager = os.environ.get('MANPAGER') or os.environ.get('PAGER')
+    if use_pager:
+        if sys.platform == 'win32': # pipes completely broken in Windows
+            return lambda text, title='': tempfile_pager(plain(text), use_pager)
+        elif os.environ.get('TERM') in ('dumb', 'emacs'):
+            return lambda text, title='': pipe_pager(plain(text), use_pager, title)
+        else:
+            return lambda text, title='': pipe_pager(text, use_pager, title)
+    if os.environ.get('TERM') in ('dumb', 'emacs'):
+        return plain_pager
+    if sys.platform == 'win32':
+        return lambda text, title='': tempfile_pager(plain(text), 'more <')
+    if hasattr(os, 'system') and os.system('(pager) 2>/dev/null') == 0:
+        return lambda text, title='': pipe_pager(text, 'pager', title)
+    if hasattr(os, 'system') and os.system('(less) 2>/dev/null') == 0:
+        return lambda text, title='': pipe_pager(text, 'less', title)
+
+    import tempfile
+    (fd, filename) = tempfile.mkstemp()
+    os.close(fd)
+    try:
+        if hasattr(os, 'system') and os.system('more "%s"' % filename) == 0:
+            return lambda text, title='': pipe_pager(text, 'more', title)
+        else:
+            return tty_pager
+    finally:
+        os.unlink(filename)
+
+
+def escape_stdout(text: str) -> str:
+    # Escape non-encodable characters to avoid encoding errors later
+    encoding = getattr(sys.stdout, 'encoding', None) or 'utf-8'
+    return text.encode(encoding, 'backslashreplace').decode(encoding)
+
+
+def escape_less(s: str) -> str:
+    return re.sub(r'([?:.%\\])', r'\\\1', s)
+
+
+def plain(text: str) -> str:
+    """Remove boldface formatting from text."""
+    return re.sub('.\b', '', text)
+
+
+def tty_pager(text: str, title: str = '') -> None:
+    """Page through text on a text terminal."""
+    lines = plain(escape_stdout(text)).split('\n')
+    has_tty = False
+    try:
+        import tty
+        import termios
+        fd = sys.stdin.fileno()
+        old = termios.tcgetattr(fd)
+        tty.setcbreak(fd)
+        has_tty = True
+
+        def getchar() -> str:
+            return sys.stdin.read(1)
+
+    except (ImportError, AttributeError, io.UnsupportedOperation):
+        def getchar() -> str:
+            return sys.stdin.readline()[:-1][:1]
+
+    try:
+        try:
+            h = int(os.environ.get('LINES', 0))
+        except ValueError:
+            h = 0
+        if h <= 1:
+            h = 25
+        r = inc = h - 1
+        sys.stdout.write('\n'.join(lines[:inc]) + '\n')
+        while lines[r:]:
+            sys.stdout.write('-- more --')
+            sys.stdout.flush()
+            c = getchar()
+
+            if c in ('q', 'Q'):
+                sys.stdout.write('\r          \r')
+                break
+            elif c in ('\r', '\n'):
+                sys.stdout.write('\r          \r' + lines[r] + '\n')
+                r = r + 1
+                continue
+            if c in ('b', 'B', '\x1b'):
+                r = r - inc - inc
+                if r < 0: r = 0
+            sys.stdout.write('\n' + '\n'.join(lines[r:r+inc]) + '\n')
+            r = r + inc
+
+    finally:
+        if has_tty:
+            termios.tcsetattr(fd, termios.TCSAFLUSH, old)
+
+
+def plain_pager(text: str, title: str = '') -> None:
+    """Simply print unformatted text.  This is the ultimate fallback."""
+    sys.stdout.write(plain(escape_stdout(text)))
+
+
+def pipe_pager(text: str, cmd: str, title: str = '') -> None:
+    """Page through text by feeding it to another program."""
+    import subprocess
+    env = os.environ.copy()
+    if title:
+        title += ' '
+    esc_title = escape_less(title)
+    prompt_string = (
+        f' {esc_title}' +
+        '?ltline %lt?L/%L.'
+        ':byte %bB?s/%s.'
+        '.'
+        '?e (END):?pB %pB\\%..'
+        ' (press h for help or q to quit)')
+    env['LESS'] = '-RmPm{0}$PM{0}$'.format(prompt_string)
+    proc = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE,
+                            errors='backslashreplace', env=env)
+    assert proc.stdin is not None
+    try:
+        with proc.stdin as pipe:
+            try:
+                pipe.write(text)
+            except KeyboardInterrupt:
+                # We've hereby abandoned whatever text hasn't been written,
+                # but the pager is still in control of the terminal.
+                pass
+    except OSError:
+        pass # Ignore broken pipes caused by quitting the pager program.
+    while True:
+        try:
+            proc.wait()
+            break
+        except KeyboardInterrupt:
+            # Ignore ctl-c like the pager itself does.  Otherwise the pager is
+            # left running and the terminal is in raw mode and unusable.
+            pass
+
+
+def tempfile_pager(text: str, cmd: str, title: str = '') -> None:
+    """Page through text by invoking a program on a temporary file."""
+    import tempfile
+    with tempfile.TemporaryDirectory() as tempdir:
+        filename = os.path.join(tempdir, 'pydoc.out')
+        with open(filename, 'w', errors='backslashreplace',
+                  encoding=os.device_encoding(0) if
+                  sys.platform == 'win32' else None
+                  ) as file:
+            file.write(text)
+        os.system(cmd + ' "' + filename + '"')
--- a/Lib/_pyrepl/reader.py
+++ b/Lib/_pyrepl/reader.py
@@ -0,0 +1,816 @@
+#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Antonio Cuni
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from __future__ import annotations
+
+import sys
+
+from contextlib import contextmanager
+from dataclasses import dataclass, field, fields
+import unicodedata
+from _colorize import can_colorize, ANSIColors  # type: ignore[import-not-found]
+
+
+from . import commands, console, input
+from .utils import ANSI_ESCAPE_SEQUENCE, wlen, str_width
+from .trace import trace
+
+
+# types
+Command = commands.Command
+from .types import Callback, SimpleContextManager, KeySpec, CommandName
+
+
+def disp_str(buffer: str) -> tuple[str, list[int]]:
+    """disp_str(buffer:string) -> (string, [int])
+
+    Return the string that should be the printed representation of
+    |buffer| and a list detailing where the characters of |buffer|
+    get used up.  E.g.:
+
+    >>> disp_str(chr(3))
+    ('^C', [1, 0])
+
+    """
+    b: list[int] = []
+    s: list[str] = []
+    for c in buffer:
+        if c == '\x1a':
+            s.append(c)
+            b.append(2)
+        elif ord(c) < 128:
+            s.append(c)
+            b.append(1)
+        elif unicodedata.category(c).startswith("C"):
+            c = r"\u%04x" % ord(c)
+            s.append(c)
+            b.extend([0] * (len(c) - 1))
+        else:
+            s.append(c)
+            b.append(str_width(c))
+    return "".join(s), b
+
+
+# syntax classes:
+
+SYNTAX_WHITESPACE, SYNTAX_WORD, SYNTAX_SYMBOL = range(3)
+
+
+def make_default_syntax_table() -> dict[str, int]:
+    # XXX perhaps should use some unicodedata here?
+    st: dict[str, int] = {}
+    for c in map(chr, range(256)):
+        st[c] = SYNTAX_SYMBOL
+    for c in [a for a in map(chr, range(256)) if a.isalnum()]:
+        st[c] = SYNTAX_WORD
+    st["\n"] = st[" "] = SYNTAX_WHITESPACE
+    return st
+
+
+def make_default_commands() -> dict[CommandName, type[Command]]:
+    result: dict[CommandName, type[Command]] = {}
+    for v in vars(commands).values():
+        if isinstance(v, type) and issubclass(v, Command) and v.__name__[0].islower():
+            result[v.__name__] = v
+            result[v.__name__.replace("_", "-")] = v
+    return result
+
+
+default_keymap: tuple[tuple[KeySpec, CommandName], ...] = tuple(
+    [
+        (r"\C-a", "beginning-of-line"),
+        (r"\C-b", "left"),
+        (r"\C-c", "interrupt"),
+        (r"\C-d", "delete"),
+        (r"\C-e", "end-of-line"),
+        (r"\C-f", "right"),
+        (r"\C-g", "cancel"),
+        (r"\C-h", "backspace"),
+        (r"\C-j", "accept"),
+        (r"\<return>", "accept"),
+        (r"\C-k", "kill-line"),
+        (r"\C-l", "clear-screen"),
+        (r"\C-m", "accept"),
+        (r"\C-t", "transpose-characters"),
+        (r"\C-u", "unix-line-discard"),
+        (r"\C-w", "unix-word-rubout"),
+        (r"\C-x\C-u", "upcase-region"),
+        (r"\C-y", "yank"),
+        *(() if sys.platform == "win32" else ((r"\C-z", "suspend"), )),
+        (r"\M-b", "backward-word"),
+        (r"\M-c", "capitalize-word"),
+        (r"\M-d", "kill-word"),
+        (r"\M-f", "forward-word"),
+        (r"\M-l", "downcase-word"),
+        (r"\M-t", "transpose-words"),
+        (r"\M-u", "upcase-word"),
+        (r"\M-y", "yank-pop"),
+        (r"\M--", "digit-arg"),
+        (r"\M-0", "digit-arg"),
+        (r"\M-1", "digit-arg"),
+        (r"\M-2", "digit-arg"),
+        (r"\M-3", "digit-arg"),
+        (r"\M-4", "digit-arg"),
+        (r"\M-5", "digit-arg"),
+        (r"\M-6", "digit-arg"),
+        (r"\M-7", "digit-arg"),
+        (r"\M-8", "digit-arg"),
+        (r"\M-9", "digit-arg"),
+        (r"\M-\n", "accept"),
+        ("\\\\", "self-insert"),
+        (r"\x1b[200~", "enable_bracketed_paste"),
+        (r"\x1b[201~", "disable_bracketed_paste"),
+        (r"\x03", "ctrl-c"),
+    ]
+    + [(c, "self-insert") for c in map(chr, range(32, 127)) if c != "\\"]
+    + [(c, "self-insert") for c in map(chr, range(128, 256)) if c.isalpha()]
+    + [
+        (r"\<up>", "up"),
+        (r"\<down>", "down"),
+        (r"\<left>", "left"),
+        (r"\C-\<left>", "backward-word"),
+        (r"\<right>", "right"),
+        (r"\C-\<right>", "forward-word"),
+        (r"\<delete>", "delete"),
+        (r"\x1b[3~", "delete"),
+        (r"\<backspace>", "backspace"),
+        (r"\M-\<backspace>", "backward-kill-word"),
+        (r"\<end>", "end-of-line"),  # was 'end'
+        (r"\<home>", "beginning-of-line"),  # was 'home'
+        (r"\<f1>", "help"),
+        (r"\<f2>", "show-history"),
+        (r"\<f3>", "paste-mode"),
+        (r"\EOF", "end"),  # the entries in the terminfo database for xterms
+        (r"\EOH", "home"),  # seem to be wrong.  this is a less than ideal
+        # workaround
+    ]
+)
+
+
+@dataclass(slots=True)
+class Reader:
+    """The Reader class implements the bare bones of a command reader,
+    handling such details as editing and cursor motion.  What it does
+    not support are such things as completion or history support -
+    these are implemented elsewhere.
+
+    Instance variables of note include:
+
+      * buffer:
+        A *list* (*not* a string at the moment :-) containing all the
+        characters that have been entered.
+      * console:
+        Hopefully encapsulates the OS dependent stuff.
+      * pos:
+        A 0-based index into `buffer' for where the insertion point
+        is.
+      * screeninfo:
+        Ahem.  This list contains some info needed to move the
+        insertion point around reasonably efficiently.
+      * cxy, lxy:
+        the position of the insertion point in screen ...
+      * syntax_table:
+        Dictionary mapping characters to `syntax class'; read the
+        emacs docs to see what this means :-)
+      * commands:
+        Dictionary mapping command names to command classes.
+      * arg:
+        The emacs-style prefix argument.  It will be None if no such
+        argument has been provided.
+      * dirty:
+        True if we need to refresh the display.
+      * kill_ring:
+        The emacs-style kill-ring; manipulated with yank & yank-pop
+      * ps1, ps2, ps3, ps4:
+        prompts.  ps1 is the prompt for a one-line input; for a
+        multiline input it looks like:
+            ps2> first line of input goes here
+            ps3> second and further
+            ps3> lines get ps3
+            ...
+            ps4> and the last one gets ps4
+        As with the usual top-level, you can set these to instances if
+        you like; str() will be called on them (once) at the beginning
+        of each command.  Don't put really long or newline containing
+        strings here, please!
+        This is just the default policy; you can change it freely by
+        overriding get_prompt() (and indeed some standard subclasses
+        do).
+      * finished:
+        handle1 will set this to a true value if a command signals
+        that we're done.
+    """
+
+    console: console.Console
+
+    ## state
+    buffer: list[str] = field(default_factory=list)
+    pos: int = 0
+    ps1: str = "->> "
+    ps2: str = "/>> "
+    ps3: str = "|.. "
+    ps4: str = R"\__ "
+    kill_ring: list[list[str]] = field(default_factory=list)
+    msg: str = ""
+    arg: int | None = None
+    dirty: bool = False
+    finished: bool = False
+    paste_mode: bool = False
+    in_bracketed_paste: bool = False
+    commands: dict[str, type[Command]] = field(default_factory=make_default_commands)
+    last_command: type[Command] | None = None
+    syntax_table: dict[str, int] = field(default_factory=make_default_syntax_table)
+    keymap: tuple[tuple[str, str], ...] = ()
+    input_trans: input.KeymapTranslator = field(init=False)
+    input_trans_stack: list[input.KeymapTranslator] = field(default_factory=list)
+    screen: list[str] = field(default_factory=list)
+    screeninfo: list[tuple[int, list[int]]] = field(init=False)
+    cxy: tuple[int, int] = field(init=False)
+    lxy: tuple[int, int] = field(init=False)
+    scheduled_commands: list[str] = field(default_factory=list)
+    can_colorize: bool = False
+    threading_hook: Callback | None = None
+
+    ## cached metadata to speed up screen refreshes
+    @dataclass
+    class RefreshCache:
+        in_bracketed_paste: bool = False
+        screen: list[str] = field(default_factory=list)
+        screeninfo: list[tuple[int, list[int]]] = field(init=False)
+        line_end_offsets: list[int] = field(default_factory=list)
+        pos: int = field(init=False)
+        cxy: tuple[int, int] = field(init=False)
+        dimensions: tuple[int, int] = field(init=False)
+        invalidated: bool = False
+
+        def update_cache(self,
+                         reader: Reader,
+                         screen: list[str],
+                         screeninfo: list[tuple[int, list[int]]],
+            ) -> None:
+            self.in_bracketed_paste = reader.in_bracketed_paste
+            self.screen = screen.copy()
+            self.screeninfo = screeninfo.copy()
+            self.pos = reader.pos
+            self.cxy = reader.cxy
+            self.dimensions = reader.console.width, reader.console.height
+            self.invalidated = False
+
+        def valid(self, reader: Reader) -> bool:
+            if self.invalidated:
+                return False
+            dimensions = reader.console.width, reader.console.height
+            dimensions_changed = dimensions != self.dimensions
+            paste_changed = reader.in_bracketed_paste != self.in_bracketed_paste
+            return not (dimensions_changed or paste_changed)
+
+        def get_cached_location(self, reader: Reader) -> tuple[int, int]:
+            if self.invalidated:
+                raise ValueError("Cache is invalidated")
+            offset = 0
+            earliest_common_pos = min(reader.pos, self.pos)
+            num_common_lines = len(self.line_end_offsets)
+            while num_common_lines > 0:
+                offset = self.line_end_offsets[num_common_lines - 1]
+                if earliest_common_pos > offset:
+                    break
+                num_common_lines -= 1
+            else:
+                offset = 0
+            return offset, num_common_lines
+
+    last_refresh_cache: RefreshCache = field(default_factory=RefreshCache)
+
+    def __post_init__(self) -> None:
+        # Enable the use of `insert` without a `prepare` call - necessary to
+        # facilitate the tab completion hack implemented for
+        # <https://bugs.python.org/issue25660>.
+        self.keymap = self.collect_keymap()
+        self.input_trans = input.KeymapTranslator(
+            self.keymap, invalid_cls="invalid-key", character_cls="self-insert"
+        )
+        self.screeninfo = [(0, [])]
+        self.cxy = self.pos2xy()
+        self.lxy = (self.pos, 0)
+        self.can_colorize = can_colorize()
+
+        self.last_refresh_cache.screeninfo = self.screeninfo
+        self.last_refresh_cache.pos = self.pos
+        self.last_refresh_cache.cxy = self.cxy
+        self.last_refresh_cache.dimensions = (0, 0)
+
+    def collect_keymap(self) -> tuple[tuple[KeySpec, CommandName], ...]:
+        return default_keymap
+
+    def calc_screen(self) -> list[str]:
+        """Translate changes in self.buffer into changes in self.console.screen."""
+        # Since the last call to calc_screen:
+        # screen and screeninfo may differ due to a completion menu being shown
+        # pos and cxy may differ due to edits, cursor movements, or completion menus
+
+        # Lines that are above both the old and new cursor position can't have changed,
+        # unless the terminal has been resized (which might cause reflowing) or we've
+        # entered or left paste mode (which changes prompts, causing reflowing).
+        num_common_lines = 0
+        offset = 0
+        if self.last_refresh_cache.valid(self):
+            offset, num_common_lines = self.last_refresh_cache.get_cached_location(self)
+
+        screen = self.last_refresh_cache.screen
+        del screen[num_common_lines:]
+
+        screeninfo = self.last_refresh_cache.screeninfo
+        del screeninfo[num_common_lines:]
+
+        last_refresh_line_end_offsets = self.last_refresh_cache.line_end_offsets
+        del last_refresh_line_end_offsets[num_common_lines:]
+
+        pos = self.pos
+        pos -= offset
+
+        prompt_from_cache = (offset and self.buffer[offset - 1] != "\n")
+
+        lines = "".join(self.buffer[offset:]).split("\n")
+
+        cursor_found = False
+        lines_beyond_cursor = 0
+        for ln, line in enumerate(lines, num_common_lines):
+            ll = len(line)
+            if 0 <= pos <= ll:
+                self.lxy = pos, ln
+                cursor_found = True
+            elif cursor_found:
+                lines_beyond_cursor += 1
+                if lines_beyond_cursor > self.console.height:
+                    # No need to keep formatting lines.
+                    # The console can't show them.
+                    break
+            if prompt_from_cache:
+                # Only the first line's prompt can come from the cache
+                prompt_from_cache = False
+                prompt = ""
+            else:
+                prompt = self.get_prompt(ln, ll >= pos >= 0)
+            while "\n" in prompt:
+                pre_prompt, _, prompt = prompt.partition("\n")
+                last_refresh_line_end_offsets.append(offset)
+                screen.append(pre_prompt)
+                screeninfo.append((0, []))
+            pos -= ll + 1
+            prompt, lp = self.process_prompt(prompt)
+            l, l2 = disp_str(line)
+            wrapcount = (wlen(l) + lp) // self.console.width
+            if wrapcount == 0:
+                offset += ll + 1  # Takes all of the line plus the newline
+                last_refresh_line_end_offsets.append(offset)
+                screen.append(prompt + l)
+                screeninfo.append((lp, l2))
+            else:
+                i = 0
+                while l:
+                    prelen = lp if i == 0 else 0
+                    index_to_wrap_before = 0
+                    column = 0
+                    for character_width in l2:
+                        if column + character_width >= self.console.width - prelen:
+                            break
+                        index_to_wrap_before += 1
+                        column += character_width
+                    pre = prompt if i == 0 else ""
+                    if len(l) > index_to_wrap_before:
+                        offset += index_to_wrap_before
+                        post = "\\"
+                        after = [1]
+                    else:
+                        offset += index_to_wrap_before + 1  # Takes the newline
+                        post = ""
+                        after = []
+                    last_refresh_line_end_offsets.append(offset)
+                    screen.append(pre + l[:index_to_wrap_before] + post)
+                    screeninfo.append((prelen, l2[:index_to_wrap_before] + after))
+                    l = l[index_to_wrap_before:]
+                    l2 = l2[index_to_wrap_before:]
+                    i += 1
+        self.screeninfo = screeninfo
+        self.cxy = self.pos2xy()
+        if self.msg:
+            for mline in self.msg.split("\n"):
+                screen.append(mline)
+                screeninfo.append((0, []))
+
+        self.last_refresh_cache.update_cache(self, screen, screeninfo)
+        return screen
+
+    @staticmethod
+    def process_prompt(prompt: str) -> tuple[str, int]:
+        """Process the prompt.
+
+        This means calculate the length of the prompt. The character \x01
+        and \x02 are used to bracket ANSI control sequences and need to be
+        excluded from the length calculation.  So also a copy of the prompt
+        is returned with these control characters removed."""
+
+        # The logic below also ignores the length of common escape
+        # sequences if they were not explicitly within \x01...\x02.
+        # They are CSI (or ANSI) sequences  ( ESC [ ... LETTER )
+
+        # wlen from utils already excludes ANSI_ESCAPE_SEQUENCE chars,
+        # which breaks the logic below so we redefine it here.
+        def wlen(s: str) -> int:
+            return sum(str_width(i) for i in s)
+
+        out_prompt = ""
+        l = wlen(prompt)
+        pos = 0
+        while True:
+            s = prompt.find("\x01", pos)
+            if s == -1:
+                break
+            e = prompt.find("\x02", s)
+            if e == -1:
+                break
+            # Found start and end brackets, subtract from string length
+            l = l - (e - s + 1)
+            keep = prompt[pos:s]
+            l -= sum(map(wlen, ANSI_ESCAPE_SEQUENCE.findall(keep)))
+            out_prompt += keep + prompt[s + 1 : e]
+            pos = e + 1
+        keep = prompt[pos:]
+        l -= sum(map(wlen, ANSI_ESCAPE_SEQUENCE.findall(keep)))
+        out_prompt += keep
+        return out_prompt, l
+
+    def bow(self, p: int | None = None) -> int:
+        """Return the 0-based index of the word break preceding p most
+        immediately.
+
+        p defaults to self.pos; word boundaries are determined using
+        self.syntax_table."""
+        if p is None:
+            p = self.pos
+        st = self.syntax_table
+        b = self.buffer
+        p -= 1
+        while p >= 0 and st.get(b[p], SYNTAX_WORD) != SYNTAX_WORD:
+            p -= 1
+        while p >= 0 and st.get(b[p], SYNTAX_WORD) == SYNTAX_WORD:
+            p -= 1
+        return p + 1
+
+    def eow(self, p: int | None = None) -> int:
+        """Return the 0-based index of the word break following p most
+        immediately.
+
+        p defaults to self.pos; word boundaries are determined using
+        self.syntax_table."""
+        if p is None:
+            p = self.pos
+        st = self.syntax_table
+        b = self.buffer
+        while p < len(b) and st.get(b[p], SYNTAX_WORD) != SYNTAX_WORD:
+            p += 1
+        while p < len(b) and st.get(b[p], SYNTAX_WORD) == SYNTAX_WORD:
+            p += 1
+        return p
+
+    def bol(self, p: int | None = None) -> int:
+        """Return the 0-based index of the line break preceding p most
+        immediately.
+
+        p defaults to self.pos."""
+        if p is None:
+            p = self.pos
+        b = self.buffer
+        p -= 1
+        while p >= 0 and b[p] != "\n":
+            p -= 1
+        return p + 1
+
+    def eol(self, p: int | None = None) -> int:
+        """Return the 0-based index of the line break following p most
+        immediately.
+
+        p defaults to self.pos."""
+        if p is None:
+            p = self.pos
+        b = self.buffer
+        while p < len(b) and b[p] != "\n":
+            p += 1
+        return p
+
+    def max_column(self, y: int) -> int:
+        """Return the last x-offset for line y"""
+        return self.screeninfo[y][0] + sum(self.screeninfo[y][1])
+
+    def max_row(self) -> int:
+        return len(self.screeninfo) - 1
+
+    def get_arg(self, default: int = 1) -> int:
+        """Return any prefix argument that the user has supplied,
+        returning `default' if there is None.  Defaults to 1.
+        """
+        if self.arg is None:
+            return default
+        return self.arg
+
+    def get_prompt(self, lineno: int, cursor_on_line: bool) -> str:
+        """Return what should be in the left-hand margin for line
+        `lineno'."""
+        if self.arg is not None and cursor_on_line:
+            prompt = f"(arg: {self.arg}) "
+        elif self.paste_mode and not self.in_bracketed_paste:
+            prompt = "(paste) "
+        elif "\n" in self.buffer:
+            if lineno == 0:
+                prompt = self.ps2
+            elif self.ps4 and lineno == self.buffer.count("\n"):
+                prompt = self.ps4
+            else:
+                prompt = self.ps3
+        else:
+            prompt = self.ps1
+
+        if self.can_colorize:
+            prompt = f"{ANSIColors.BOLD_MAGENTA}{prompt}{ANSIColors.RESET}"
+        return prompt
+
+    def push_input_trans(self, itrans: input.KeymapTranslator) -> None:
+        self.input_trans_stack.append(self.input_trans)
+        self.input_trans = itrans
+
+    def pop_input_trans(self) -> None:
+        self.input_trans = self.input_trans_stack.pop()
+
+    def setpos_from_xy(self, x: int, y: int) -> None:
+        """Set pos according to coordinates x, y"""
+        pos = 0
+        i = 0
+        while i < y:
+            prompt_len, character_widths = self.screeninfo[i]
+            offset = len(character_widths) - character_widths.count(0)
+            in_wrapped_line = prompt_len + sum(character_widths) >= self.console.width
+            if in_wrapped_line:
+                pos += offset - 1  # -1 cause backslash is not in buffer
+            else:
+                pos += offset + 1  # +1 cause newline is in buffer
+            i += 1
+
+        j = 0
+        cur_x = self.screeninfo[i][0]
+        while cur_x < x:
+            if self.screeninfo[i][1][j] == 0:
+                continue
+            cur_x += self.screeninfo[i][1][j]
+            j += 1
+            pos += 1
+
+        self.pos = pos
+
+    def pos2xy(self) -> tuple[int, int]:
+        """Return the x, y coordinates of position 'pos'."""
+        # this *is* incomprehensible, yes.
+        p, y = 0, 0
+        l2: list[int] = []
+        pos = self.pos
+        assert 0 <= pos <= len(self.buffer)
+        if pos == len(self.buffer) and len(self.screeninfo) > 0:
+            y = len(self.screeninfo) - 1
+            p, l2 = self.screeninfo[y]
+            return p + sum(l2) + l2.count(0), y
+
+        for p, l2 in self.screeninfo:
+            l = len(l2) - l2.count(0)
+            in_wrapped_line = p + sum(l2) >= self.console.width
+            offset = l - 1 if in_wrapped_line else l  # need to remove backslash
+            if offset >= pos:
+                break
+
+            if p + sum(l2) >= self.console.width:
+                pos -= l - 1  # -1 cause backslash is not in buffer
+            else:
+                pos -= l + 1  # +1 cause newline is in buffer
+            y += 1
+        return p + sum(l2[:pos]), y
+
+    def insert(self, text: str | list[str]) -> None:
+        """Insert 'text' at the insertion point."""
+        self.buffer[self.pos : self.pos] = list(text)
+        self.pos += len(text)
+        self.dirty = True
+
+    def update_cursor(self) -> None:
+        """Move the cursor to reflect changes in self.pos"""
+        self.cxy = self.pos2xy()
+        self.console.move_cursor(*self.cxy)
+
+    def after_command(self, cmd: Command) -> None:
+        """This function is called to allow post command cleanup."""
+        if getattr(cmd, "kills_digit_arg", True):
+            if self.arg is not None:
+                self.dirty = True
+            self.arg = None
+
+    def prepare(self) -> None:
+        """Get ready to run.  Call restore when finished.  You must not
+        write to the console in between the calls to prepare and
+        restore."""
+        try:
+            self.console.prepare()
+            self.arg = None
+            self.finished = False
+            del self.buffer[:]
+            self.pos = 0
+            self.dirty = True
+            self.last_command = None
+            self.calc_screen()
+        except BaseException:
+            self.restore()
+            raise
+
+        while self.scheduled_commands:
+            cmd = self.scheduled_commands.pop()
+            self.do_cmd((cmd, []))
+
+    def last_command_is(self, cls: type) -> bool:
+        if not self.last_command:
+            return False
+        return issubclass(cls, self.last_command)
+
+    def restore(self) -> None:
+        """Clean up after a run."""
+        self.console.restore()
+
+    @contextmanager
+    def suspend(self) -> SimpleContextManager:
+        """A context manager to delegate to another reader."""
+        prev_state = {f.name: getattr(self, f.name) for f in fields(self)}
+        try:
+            self.restore()
+            yield
+        finally:
+            for arg in ("msg", "ps1", "ps2", "ps3", "ps4", "paste_mode"):
+                setattr(self, arg, prev_state[arg])
+            self.prepare()
+
+    def finish(self) -> None:
+        """Called when a command signals that we're finished."""
+        pass
+
+    def error(self, msg: str = "none") -> None:
+        self.msg = "! " + msg + " "
+        self.dirty = True
+        self.console.beep()
+
+    def update_screen(self) -> None:
+        if self.dirty:
+            self.refresh()
+
+    def refresh(self) -> None:
+        """Recalculate and refresh the screen."""
+        if self.in_bracketed_paste and self.buffer and not self.buffer[-1] == "\n":
+            return
+
+        # this call sets up self.cxy, so call it first.
+        self.screen = self.calc_screen()
+        self.console.refresh(self.screen, self.cxy)
+        self.dirty = False
+
+    def do_cmd(self, cmd: tuple[str, list[str]]) -> None:
+        """`cmd` is a tuple of "event_name" and "event", which in the current
+        implementation is always just the "buffer" which happens to be a list
+        of single-character strings."""
+
+        trace("received command {cmd}", cmd=cmd)
+        if isinstance(cmd[0], str):
+            command_type = self.commands.get(cmd[0], commands.invalid_command)
+        elif isinstance(cmd[0], type):
+            command_type = cmd[0]
+        else:
+            return  # nothing to do
+
+        command = command_type(self, *cmd)  # type: ignore[arg-type]
+        command.do()
+
+        self.after_command(command)
+
+        if self.dirty:
+            self.refresh()
+        else:
+            self.update_cursor()
+
+        if not isinstance(cmd, commands.digit_arg):
+            self.last_command = command_type
+
+        self.finished = bool(command.finish)
+        if self.finished:
+            self.console.finish()
+            self.finish()
+
+    def run_hooks(self) -> None:
+        threading_hook = self.threading_hook
+        if threading_hook is None and 'threading' in sys.modules:
+            from ._threading_handler import install_threading_hook
+            install_threading_hook(self)
+        if threading_hook is not None:
+            try:
+                threading_hook()
+            except Exception:
+                pass
+
+        input_hook = self.console.input_hook
+        if input_hook:
+            try:
+                input_hook()
+            except Exception:
+                pass
+
+    def handle1(self, block: bool = True) -> bool:
+        """Handle a single event.  Wait as long as it takes if block
+        is true (the default), otherwise return False if no event is
+        pending."""
+
+        if self.msg:
+            self.msg = ""
+            self.dirty = True
+
+        while True:
+            # We use the same timeout as in readline.c: 100ms
+            self.run_hooks()
+            self.console.wait(100)
+            event = self.console.get_event(block=False)
+            if not event:
+                if block:
+                    continue
+                return False
+
+            translate = True
+
+            if event.evt == "key":
+                self.input_trans.push(event)
+            elif event.evt == "scroll":
+                self.refresh()
+            elif event.evt == "resize":
+                self.refresh()
+            else:
+                translate = False
+
+            if translate:
+                cmd = self.input_trans.get()
+            else:
+                cmd = [event.evt, event.data]
+
+            if cmd is None:
+                if block:
+                    continue
+                return False
+
+            self.do_cmd(cmd)
+            return True
+
+    def push_char(self, char: int | bytes) -> None:
+        self.console.push_char(char)
+        self.handle1(block=False)
+
+    def readline(self, startup_hook: Callback | None = None) -> str:
+        """Read a line.  The implementation of this method also shows
+        how to drive Reader if you want more control over the event
+        loop."""
+        self.prepare()
+        try:
+            if startup_hook is not None:
+                startup_hook()
+            self.refresh()
+            while not self.finished:
+                self.handle1()
+            return self.get_unicode()
+
+        finally:
+            self.restore()
+
+    def bind(self, spec: KeySpec, command: CommandName) -> None:
+        self.keymap = self.keymap + ((spec, command),)
+        self.input_trans = input.KeymapTranslator(
+            self.keymap, invalid_cls="invalid-key", character_cls="self-insert"
+        )
+
+    def get_unicode(self) -> str:
+        """Return the current buffer as a unicode string."""
+        return "".join(self.buffer)
--- a/Lib/_pyrepl/readline.py
+++ b/Lib/_pyrepl/readline.py
@@ -0,0 +1,598 @@
+#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Alex Gaynor
+#                       Antonio Cuni
+#                       Armin Rigo
+#                       Holger Krekel
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""A compatibility wrapper reimplementing the 'readline' standard module
+on top of pyrepl.  Not all functionalities are supported.  Contains
+extensions for multiline input.
+"""
+
+from __future__ import annotations
+
+import warnings
+from dataclasses import dataclass, field
+
+import os
+from site import gethistoryfile   # type: ignore[attr-defined]
+import sys
+from rlcompleter import Completer as RLCompleter
+
+from . import commands, historical_reader
+from .completing_reader import CompletingReader
+from .console import Console as ConsoleType
+
+Console: type[ConsoleType]
+_error: tuple[type[Exception], ...] | type[Exception]
+try:
+    from .unix_console import UnixConsole as Console, _error
+except ImportError:
+    from .windows_console import WindowsConsole as Console, _error
+
+ENCODING = sys.getdefaultencoding() or "latin1"
+
+
+# types
+Command = commands.Command
+from collections.abc import Callable, Collection
+from .types import Callback, Completer, KeySpec, CommandName
+
+TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Any, Mapping
+
+
+MoreLinesCallable = Callable[[str], bool]
+
+
+__all__ = [
+    "add_history",
+    "clear_history",
+    "get_begidx",
+    "get_completer",
+    "get_completer_delims",
+    "get_current_history_length",
+    "get_endidx",
+    "get_history_item",
+    "get_history_length",
+    "get_line_buffer",
+    "insert_text",
+    "parse_and_bind",
+    "read_history_file",
+    # "read_init_file",
+    # "redisplay",
+    "remove_history_item",
+    "replace_history_item",
+    "set_auto_history",
+    "set_completer",
+    "set_completer_delims",
+    "set_history_length",
+    # "set_pre_input_hook",
+    "set_startup_hook",
+    "write_history_file",
+    # ---- multiline extensions ----
+    "multiline_input",
+]
+
+# ____________________________________________________________
+
+@dataclass
+class ReadlineConfig:
+    readline_completer: Completer | None = None
+    completer_delims: frozenset[str] = frozenset(" \t\n`~!@#$%^&*()-=+[{]}\\|;:'\",<>/?")
+
+
+@dataclass(kw_only=True)
+class ReadlineAlikeReader(historical_reader.HistoricalReader, CompletingReader):
+    # Class fields
+    assume_immutable_completions = False
+    use_brackets = False
+    sort_in_column = True
+
+    # Instance fields
+    config: ReadlineConfig
+    more_lines: MoreLinesCallable | None = None
+    last_used_indentation: str | None = None
+
+    def __post_init__(self) -> None:
+        super().__post_init__()
+        self.commands["maybe_accept"] = maybe_accept
+        self.commands["maybe-accept"] = maybe_accept
+        self.commands["backspace_dedent"] = backspace_dedent
+        self.commands["backspace-dedent"] = backspace_dedent
+
+    def error(self, msg: str = "none") -> None:
+        pass  # don't show error messages by default
+
+    def get_stem(self) -> str:
+        b = self.buffer
+        p = self.pos - 1
+        completer_delims = self.config.completer_delims
+        while p >= 0 and b[p] not in completer_delims:
+            p -= 1
+        return "".join(b[p + 1 : self.pos])
+
+    def get_completions(self, stem: str) -> list[str]:
+        if len(stem) == 0 and self.more_lines is not None:
+            b = self.buffer
+            p = self.pos
+            while p > 0 and b[p - 1] != "\n":
+                p -= 1
+            num_spaces = 4 - ((self.pos - p) % 4)
+            return [" " * num_spaces]
+        result = []
+        function = self.config.readline_completer
+        if function is not None:
+            try:
+                stem = str(stem)  # rlcompleter.py seems to not like unicode
+            except UnicodeEncodeError:
+                pass  # but feed unicode anyway if we have no choice
+            state = 0
+            while True:
+                try:
+                    next = function(stem, state)
+                except Exception:
+                    break
+                if not isinstance(next, str):
+                    break
+                result.append(next)
+                state += 1
+            # emulate the behavior of the standard readline that sorts
+            # the completions before displaying them.
+            result.sort()
+        return result
+
+    def get_trimmed_history(self, maxlength: int) -> list[str]:
+        if maxlength >= 0:
+            cut = len(self.history) - maxlength
+            if cut < 0:
+                cut = 0
+        else:
+            cut = 0
+        return self.history[cut:]
+
+    def update_last_used_indentation(self) -> None:
+        indentation = _get_first_indentation(self.buffer)
+        if indentation is not None:
+            self.last_used_indentation = indentation
+
+    # --- simplified support for reading multiline Python statements ---
+
+    def collect_keymap(self) -> tuple[tuple[KeySpec, CommandName], ...]:
+        return super().collect_keymap() + (
+            (r"\n", "maybe-accept"),
+            (r"\<backspace>", "backspace-dedent"),
+        )
+
+    def after_command(self, cmd: Command) -> None:
+        super().after_command(cmd)
+        if self.more_lines is None:
+            # Force single-line input if we are in raw_input() mode.
+            # Although there is no direct way to add a \n in this mode,
+            # multiline buffers can still show up using various
+            # commands, e.g. navigating the history.
+            try:
+                index = self.buffer.index("\n")
+            except ValueError:
+                pass
+            else:
+                self.buffer = self.buffer[:index]
+                if self.pos > len(self.buffer):
+                    self.pos = len(self.buffer)
+
+
+def set_auto_history(_should_auto_add_history: bool) -> None:
+    """Enable or disable automatic history"""
+    historical_reader.should_auto_add_history = bool(_should_auto_add_history)
+
+
+def _get_this_line_indent(buffer: list[str], pos: int) -> int:
+    indent = 0
+    while pos > 0 and buffer[pos - 1] in " \t":
+        indent += 1
+        pos -= 1
+    if pos > 0 and buffer[pos - 1] == "\n":
+        return indent
+    return 0
+
+
+def _get_previous_line_indent(buffer: list[str], pos: int) -> tuple[int, int | None]:
+    prevlinestart = pos
+    while prevlinestart > 0 and buffer[prevlinestart - 1] != "\n":
+        prevlinestart -= 1
+    prevlinetext = prevlinestart
+    while prevlinetext < pos and buffer[prevlinetext] in " \t":
+        prevlinetext += 1
+    if prevlinetext == pos:
+        indent = None
+    else:
+        indent = prevlinetext - prevlinestart
+    return prevlinestart, indent
+
+
+def _get_first_indentation(buffer: list[str]) -> str | None:
+    indented_line_start = None
+    for i in range(len(buffer)):
+        if (i < len(buffer) - 1
+            and buffer[i] == "\n"
+            and buffer[i + 1] in " \t"
+        ):
+            indented_line_start = i + 1
+        elif indented_line_start is not None and buffer[i] not in " \t\n":
+            return ''.join(buffer[indented_line_start : i])
+    return None
+
+
+def _should_auto_indent(buffer: list[str], pos: int) -> bool:
+    # check if last character before "pos" is a colon, ignoring
+    # whitespaces and comments.
+    last_char = None
+    while pos > 0:
+        pos -= 1
+        if last_char is None:
+            if buffer[pos] not in " \t\n#":  # ignore whitespaces and comments
+                last_char = buffer[pos]
+        else:
+            # even if we found a non-whitespace character before
+            # original pos, we keep going back until newline is reached
+            # to make sure we ignore comments
+            if buffer[pos] == "\n":
+                break
+            if buffer[pos] == "#":
+                last_char = None
+    return last_char == ":"
+
+
+class maybe_accept(commands.Command):
+    def do(self) -> None:
+        r: ReadlineAlikeReader
+        r = self.reader  # type: ignore[assignment]
+        r.dirty = True  # this is needed to hide the completion menu, if visible
+
+        if self.reader.in_bracketed_paste:
+            r.insert("\n")
+            return
+
+        # if there are already several lines and the cursor
+        # is not on the last one, always insert a new \n.
+        text = r.get_unicode()
+
+        if "\n" in r.buffer[r.pos :] or (
+            r.more_lines is not None and r.more_lines(text)
+        ):
+            def _newline_before_pos():
+                before_idx = r.pos - 1
+                while before_idx > 0 and text[before_idx].isspace():
+                    before_idx -= 1
+                return text[before_idx : r.pos].count("\n") > 0
+
+            # if there's already a new line before the cursor then
+            # even if the cursor is followed by whitespace, we assume
+            # the user is trying to terminate the block
+            if _newline_before_pos() and text[r.pos:].isspace():
+                self.finish = True
+                return
+
+            # auto-indent the next line like the previous line
+            prevlinestart, indent = _get_previous_line_indent(r.buffer, r.pos)
+            r.insert("\n")
+            if not self.reader.paste_mode:
+                if indent:
+                    for i in range(prevlinestart, prevlinestart + indent):
+                        r.insert(r.buffer[i])
+                r.update_last_used_indentation()
+                if _should_auto_indent(r.buffer, r.pos):
+                    if r.last_used_indentation is not None:
+                        indentation = r.last_used_indentation
+                    else:
+                        # default
+                        indentation = " " * 4
+                    r.insert(indentation)
+        elif not self.reader.paste_mode:
+            self.finish = True
+        else:
+            r.insert("\n")
+
+
+class backspace_dedent(commands.Command):
+    def do(self) -> None:
+        r = self.reader
+        b = r.buffer
+        if r.pos > 0:
+            repeat = 1
+            if b[r.pos - 1] != "\n":
+                indent = _get_this_line_indent(b, r.pos)
+                if indent > 0:
+                    ls = r.pos - indent
+                    while ls > 0:
+                        ls, pi = _get_previous_line_indent(b, ls - 1)
+                        if pi is not None and pi < indent:
+                            repeat = indent - pi
+                            break
+            r.pos -= repeat
+            del b[r.pos : r.pos + repeat]
+            r.dirty = True
+        else:
+            self.reader.error("can't backspace at start")
+
+
+# ____________________________________________________________
+
+
+@dataclass(slots=True)
+class _ReadlineWrapper:
+    f_in: int = -1
+    f_out: int = -1
+    reader: ReadlineAlikeReader | None = field(default=None, repr=False)
+    saved_history_length: int = -1
+    startup_hook: Callback | None = None
+    config: ReadlineConfig = field(default_factory=ReadlineConfig, repr=False)
+
+    def __post_init__(self) -> None:
+        if self.f_in == -1:
+            self.f_in = os.dup(0)
+        if self.f_out == -1:
+            self.f_out = os.dup(1)
+
+    def get_reader(self) -> ReadlineAlikeReader:
+        if self.reader is None:
+            console = Console(self.f_in, self.f_out, encoding=ENCODING)
+            self.reader = ReadlineAlikeReader(console=console, config=self.config)
+        return self.reader
+
+    def input(self, prompt: object = "") -> str:
+        try:
+            reader = self.get_reader()
+        except _error:
+            assert raw_input is not None
+            return raw_input(prompt)
+        prompt_str = str(prompt)
+        reader.ps1 = prompt_str
+        sys.audit("builtins.input", prompt_str)
+        result = reader.readline(startup_hook=self.startup_hook)
+        sys.audit("builtins.input/result", result)
+        return result
+
+    def multiline_input(self, more_lines: MoreLinesCallable, ps1: str, ps2: str) -> str:
+        """Read an input on possibly multiple lines, asking for more
+        lines as long as 'more_lines(unicodetext)' returns an object whose
+        boolean value is true.
+        """
+        reader = self.get_reader()
+        saved = reader.more_lines
+        try:
+            reader.more_lines = more_lines
+            reader.ps1 = ps1
+            reader.ps2 = ps1
+            reader.ps3 = ps2
+            reader.ps4 = ""
+            with warnings.catch_warnings(action="ignore"):
+                return reader.readline()
+        finally:
+            reader.more_lines = saved
+            reader.paste_mode = False
+
+    def parse_and_bind(self, string: str) -> None:
+        pass  # XXX we don't support parsing GNU-readline-style init files
+
+    def set_completer(self, function: Completer | None = None) -> None:
+        self.config.readline_completer = function
+
+    def get_completer(self) -> Completer | None:
+        return self.config.readline_completer
+
+    def set_completer_delims(self, delimiters: Collection[str]) -> None:
+        self.config.completer_delims = frozenset(delimiters)
+
+    def get_completer_delims(self) -> str:
+        return "".join(sorted(self.config.completer_delims))
+
+    def _histline(self, line: str) -> str:
+        line = line.rstrip("\n")
+        return line
+
+    def get_history_length(self) -> int:
+        return self.saved_history_length
+
+    def set_history_length(self, length: int) -> None:
+        self.saved_history_length = length
+
+    def get_current_history_length(self) -> int:
+        return len(self.get_reader().history)
+
+    def read_history_file(self, filename: str = gethistoryfile()) -> None:
+        # multiline extension (really a hack) for the end of lines that
+        # are actually continuations inside a single multiline_input()
+        # history item: we use \r\n instead of just \n.  If the history
+        # file is passed to GNU readline, the extra \r are just ignored.
+        history = self.get_reader().history
+
+        with open(os.path.expanduser(filename), 'rb') as f:
+            is_editline = f.readline().startswith(b"_HiStOrY_V2_")
+            if is_editline:
+                encoding = "unicode-escape"
+            else:
+                f.seek(0)
+                encoding = "utf-8"
+
+            lines = [line.decode(encoding, errors='replace') for line in f.read().split(b'\n')]
+            buffer = []
+            for line in lines:
+                if line.endswith("\r"):
+                    buffer.append(line+'\n')
+                else:
+                    line = self._histline(line)
+                    if buffer:
+                        line = self._histline("".join(buffer).replace("\r", "") + line)
+                        del buffer[:]
+                    if line:
+                        history.append(line)
+
+    def write_history_file(self, filename: str = gethistoryfile()) -> None:
+        maxlength = self.saved_history_length
+        history = self.get_reader().get_trimmed_history(maxlength)
+        f = open(os.path.expanduser(filename), "w",
+                 encoding="utf-8", newline="\n")
+        with f:
+            for entry in history:
+                entry = entry.replace("\n", "\r\n")  # multiline history support
+                f.write(entry + "\n")
+
+    def clear_history(self) -> None:
+        del self.get_reader().history[:]
+
+    def get_history_item(self, index: int) -> str | None:
+        history = self.get_reader().history
+        if 1 <= index <= len(history):
+            return history[index - 1]
+        else:
+            return None  # like readline.c
+
+    def remove_history_item(self, index: int) -> None:
+        history = self.get_reader().history
+        if 0 <= index < len(history):
+            del history[index]
+        else:
+            raise ValueError("No history item at position %d" % index)
+            # like readline.c
+
+    def replace_history_item(self, index: int, line: str) -> None:
+        history = self.get_reader().history
+        if 0 <= index < len(history):
+            history[index] = self._histline(line)
+        else:
+            raise ValueError("No history item at position %d" % index)
+            # like readline.c
+
+    def add_history(self, line: str) -> None:
+        self.get_reader().history.append(self._histline(line))
+
+    def set_startup_hook(self, function: Callback | None = None) -> None:
+        self.startup_hook = function
+
+    def get_line_buffer(self) -> str:
+        return self.get_reader().get_unicode()
+
+    def _get_idxs(self) -> tuple[int, int]:
+        start = cursor = self.get_reader().pos
+        buf = self.get_line_buffer()
+        for i in range(cursor - 1, -1, -1):
+            if buf[i] in self.get_completer_delims():
+                break
+            start = i
+        return start, cursor
+
+    def get_begidx(self) -> int:
+        return self._get_idxs()[0]
+
+    def get_endidx(self) -> int:
+        return self._get_idxs()[1]
+
+    def insert_text(self, text: str) -> None:
+        self.get_reader().insert(text)
+
+
+_wrapper = _ReadlineWrapper()
+
+# ____________________________________________________________
+# Public API
+
+parse_and_bind = _wrapper.parse_and_bind
+set_completer = _wrapper.set_completer
+get_completer = _wrapper.get_completer
+set_completer_delims = _wrapper.set_completer_delims
+get_completer_delims = _wrapper.get_completer_delims
+get_history_length = _wrapper.get_history_length
+set_history_length = _wrapper.set_history_length
+get_current_history_length = _wrapper.get_current_history_length
+read_history_file = _wrapper.read_history_file
+write_history_file = _wrapper.write_history_file
+clear_history = _wrapper.clear_history
+get_history_item = _wrapper.get_history_item
+remove_history_item = _wrapper.remove_history_item
+replace_history_item = _wrapper.replace_history_item
+add_history = _wrapper.add_history
+set_startup_hook = _wrapper.set_startup_hook
+get_line_buffer = _wrapper.get_line_buffer
+get_begidx = _wrapper.get_begidx
+get_endidx = _wrapper.get_endidx
+insert_text = _wrapper.insert_text
+
+# Extension
+multiline_input = _wrapper.multiline_input
+
+# Internal hook
+_get_reader = _wrapper.get_reader
+
+# ____________________________________________________________
+# Stubs
+
+
+def _make_stub(_name: str, _ret: object) -> None:
+    def stub(*args: object, **kwds: object) -> None:
+        import warnings
+
+        warnings.warn("readline.%s() not implemented" % _name, stacklevel=2)
+
+    stub.__name__ = _name
+    globals()[_name] = stub
+
+
+for _name, _ret in [
+    ("read_init_file", None),
+    ("redisplay", None),
+    ("set_pre_input_hook", None),
+]:
+    assert _name not in globals(), _name
+    _make_stub(_name, _ret)
+
+# ____________________________________________________________
+
+
+def _setup(namespace: Mapping[str, Any]) -> None:
+    global raw_input
+    if raw_input is not None:
+        return  # don't run _setup twice
+
+    try:
+        f_in = sys.stdin.fileno()
+        f_out = sys.stdout.fileno()
+    except (AttributeError, ValueError):
+        return
+    if not os.isatty(f_in) or not os.isatty(f_out):
+        return
+
+    _wrapper.f_in = f_in
+    _wrapper.f_out = f_out
+
+    # set up namespace in rlcompleter, which requires it to be a bona fide dict
+    if not isinstance(namespace, dict):
+        namespace = dict(namespace)
+    _wrapper.config.readline_completer = RLCompleter(namespace).complete
+
+    # this is not really what readline.c does.  Better than nothing I guess
+    import builtins
+    raw_input = builtins.input
+    builtins.input = _wrapper.input
+
+
+raw_input: Callable[[object], str] | None = None
--- a/Lib/_pyrepl/simple_interact.py
+++ b/Lib/_pyrepl/simple_interact.py
@@ -0,0 +1,167 @@
+#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""This is an alternative to python_reader which tries to emulate
+the CPython prompt as closely as possible, with the exception of
+allowing multiline input and multiline history entries.
+"""
+
+from __future__ import annotations
+
+import _sitebuiltins
+import linecache
+import functools
+import os
+import sys
+import code
+
+from .readline import _get_reader, multiline_input
+
+TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import Any
+
+
+_error: tuple[type[Exception], ...] | type[Exception]
+try:
+    from .unix_console import _error
+except ModuleNotFoundError:
+    from .windows_console import _error
+
+def check() -> str:
+    """Returns the error message if there is a problem initializing the state."""
+    try:
+        _get_reader()
+    except _error as e:
+        if term := os.environ.get("TERM", ""):
+            term = f"; TERM={term}"
+        return str(str(e) or repr(e) or "unknown error") + term
+    return ""
+
+
+def _strip_final_indent(text: str) -> str:
+    # kill spaces and tabs at the end, but only if they follow '\n'.
+    # meant to remove the auto-indentation only (although it would of
+    # course also remove explicitly-added indentation).
+    short = text.rstrip(" \t")
+    n = len(short)
+    if n > 0 and text[n - 1] == "\n":
+        return short
+    return text
+
+
+def _clear_screen():
+    reader = _get_reader()
+    reader.scheduled_commands.append("clear_screen")
+
+
+REPL_COMMANDS = {
+    "exit": _sitebuiltins.Quitter('exit', ''),
+    "quit": _sitebuiltins.Quitter('quit' ,''),
+    "copyright": _sitebuiltins._Printer('copyright', sys.copyright),
+    "help": _sitebuiltins._Helper(),
+    "clear": _clear_screen,
+    "\x1a": _sitebuiltins.Quitter('\x1a', ''),
+}
+
+
+def _more_lines(console: code.InteractiveConsole, unicodetext: str) -> bool:
+    # ooh, look at the hack:
+    src = _strip_final_indent(unicodetext)
+    try:
+        code = console.compile(src, "<stdin>", "single")
+    except (OverflowError, SyntaxError, ValueError):
+        lines = src.splitlines(keepends=True)
+        if len(lines) == 1:
+            return False
+
+        last_line = lines[-1]
+        was_indented = last_line.startswith((" ", "\t"))
+        not_empty = last_line.strip() != ""
+        incomplete = not last_line.endswith("\n")
+        return (was_indented or not_empty) and incomplete
+    else:
+        return code is None
+
+
+def run_multiline_interactive_console(
+    console: code.InteractiveConsole,
+    *,
+    future_flags: int = 0,
+) -> None:
+    from .readline import _setup
+    _setup(console.locals)
+    if future_flags:
+        console.compile.compiler.flags |= future_flags
+
+    more_lines = functools.partial(_more_lines, console)
+    input_n = 0
+
+    def maybe_run_command(statement: str) -> bool:
+        statement = statement.strip()
+        if statement in console.locals or statement not in REPL_COMMANDS:
+            return False
+
+        reader = _get_reader()
+        reader.history.pop()  # skip internal commands in history
+        command = REPL_COMMANDS[statement]
+        if callable(command):
+            # Make sure that history does not change because of commands
+            with reader.suspend_history():
+                command()
+            return True
+        return False
+
+    while 1:
+        try:
+            try:
+                sys.stdout.flush()
+            except Exception:
+                pass
+
+            ps1 = getattr(sys, "ps1", ">>> ")
+            ps2 = getattr(sys, "ps2", "... ")
+            try:
+                statement = multiline_input(more_lines, ps1, ps2)
+            except EOFError:
+                break
+
+            if maybe_run_command(statement):
+                continue
+
+            input_name = f"<python-input-{input_n}>"
+            linecache._register_code(input_name, statement, "<stdin>")  # type: ignore[attr-defined]
+            more = console.push(_strip_final_indent(statement), filename=input_name, _symbol="single")  # type: ignore[call-arg]
+            assert not more
+            input_n += 1
+        except KeyboardInterrupt:
+            r = _get_reader()
+            if r.input_trans is r.isearch_trans:
+                r.do_cmd(("isearch-end", [""]))
+            r.pos = len(r.get_unicode())
+            r.dirty = True
+            r.refresh()
+            r.in_bracketed_paste = False
+            console.write("\nKeyboardInterrupt\n")
+            console.resetbuffer()
+        except MemoryError:
+            console.write("\nMemoryError\n")
+            console.resetbuffer()
--- a/Lib/_pyrepl/trace.py
+++ b/Lib/_pyrepl/trace.py
@@ -0,0 +1,21 @@
+from __future__ import annotations
+
+import os
+
+# types
+if False:
+    from typing import IO
+
+
+trace_file: IO[str] | None = None
+if trace_filename := os.environ.get("PYREPL_TRACE"):
+    trace_file = open(trace_filename, "a")
+
+
+def trace(line: str, *k: object, **kw: object) -> None:
+    if trace_file is None:
+        return
+    if k or kw:
+        line = line.format(*k, **kw)
+    trace_file.write(line + "\n")
+    trace_file.flush()
--- a/Lib/_pyrepl/types.py
+++ b/Lib/_pyrepl/types.py
@@ -0,0 +1,8 @@
+from collections.abc import Callable, Iterator
+
+Callback = Callable[[], object]
+SimpleContextManager = Iterator[None]
+KeySpec = str  # like r"\C-c"
+CommandName = str  # like "interrupt"
+EventTuple = tuple[CommandName, str]
+Completer = Callable[[str, int], str | None]
--- a/Lib/_pyrepl/unix_console.py
+++ b/Lib/_pyrepl/unix_console.py
@@ -0,0 +1,810 @@
+#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Antonio Cuni
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from __future__ import annotations
+
+import errno
+import os
+import re
+import select
+import signal
+import struct
+import termios
+import time
+import platform
+from fcntl import ioctl
+
+from . import curses
+from .console import Console, Event
+from .fancy_termios import tcgetattr, tcsetattr
+from .trace import trace
+from .unix_eventqueue import EventQueue
+from .utils import wlen
+
+
+TYPE_CHECKING = False
+
+# types
+if TYPE_CHECKING:
+    from typing import IO, Literal, overload
+else:
+    overload = lambda func: None
+
+
+class InvalidTerminal(RuntimeError):
+    pass
+
+
+_error = (termios.error, curses.error, InvalidTerminal)
+
+SIGWINCH_EVENT = "repaint"
+
+FIONREAD = getattr(termios, "FIONREAD", None)
+TIOCGWINSZ = getattr(termios, "TIOCGWINSZ", None)
+
+# ------------ start of baudrate definitions ------------
+
+# Add (possibly) missing baudrates (check termios man page) to termios
+
+
+def add_baudrate_if_supported(dictionary: dict[int, int], rate: int) -> None:
+    baudrate_name = "B%d" % rate
+    if hasattr(termios, baudrate_name):
+        dictionary[getattr(termios, baudrate_name)] = rate
+
+
+# Check the termios man page (Line speed) to know where these
+# values come from.
+potential_baudrates = [
+    0,
+    110,
+    115200,
+    1200,
+    134,
+    150,
+    1800,
+    19200,
+    200,
+    230400,
+    2400,
+    300,
+    38400,
+    460800,
+    4800,
+    50,
+    57600,
+    600,
+    75,
+    9600,
+]
+
+ratedict: dict[int, int] = {}
+for rate in potential_baudrates:
+    add_baudrate_if_supported(ratedict, rate)
+
+# Clean up variables to avoid unintended usage
+del rate, add_baudrate_if_supported
+
+# ------------ end of baudrate definitions ------------
+
+delayprog = re.compile(b"\\$<([0-9]+)((?:/|\\*){0,2})>")
+
+try:
+    poll: type[select.poll] = select.poll
+except AttributeError:
+    # this is exactly the minumum necessary to support what we
+    # do with poll objects
+    class MinimalPoll:
+        def __init__(self):
+            pass
+
+        def register(self, fd, flag):
+            self.fd = fd
+        # note: The 'timeout' argument is received as *milliseconds*
+        def poll(self, timeout: float | None = None) -> list[int]:
+            if timeout is None:
+                r, w, e = select.select([self.fd], [], [])
+            else:
+                r, w, e = select.select([self.fd], [], [], timeout/1000)
+            return r
+
+    poll = MinimalPoll  # type: ignore[assignment]
+
+
+class UnixConsole(Console):
+    def __init__(
+        self,
+        f_in: IO[bytes] | int = 0,
+        f_out: IO[bytes] | int = 1,
+        term: str = "",
+        encoding: str = "",
+    ):
+        """
+        Initialize the UnixConsole.
+
+        Parameters:
+        - f_in (int or file-like object): Input file descriptor or object.
+        - f_out (int or file-like object): Output file descriptor or object.
+        - term (str): Terminal name.
+        - encoding (str): Encoding to use for I/O operations.
+        """
+        super().__init__(f_in, f_out, term, encoding)
+
+        self.pollob = poll()
+        self.pollob.register(self.input_fd, select.POLLIN)
+        self.input_buffer = b""
+        self.input_buffer_pos = 0
+        curses.setupterm(term or None, self.output_fd)
+        self.term = term
+
+        @overload
+        def _my_getstr(cap: str, optional: Literal[False] = False) -> bytes: ...
+
+        @overload
+        def _my_getstr(cap: str, optional: bool) -> bytes | None: ...
+
+        def _my_getstr(cap: str, optional: bool = False) -> bytes | None:
+            r = curses.tigetstr(cap)
+            if not optional and r is None:
+                raise InvalidTerminal(
+                    f"terminal doesn't have the required {cap} capability"
+                )
+            return r
+
+        self._bel = _my_getstr("bel")
+        self._civis = _my_getstr("civis", optional=True)
+        self._clear = _my_getstr("clear")
+        self._cnorm = _my_getstr("cnorm", optional=True)
+        self._cub = _my_getstr("cub", optional=True)
+        self._cub1 = _my_getstr("cub1", optional=True)
+        self._cud = _my_getstr("cud", optional=True)
+        self._cud1 = _my_getstr("cud1", optional=True)
+        self._cuf = _my_getstr("cuf", optional=True)
+        self._cuf1 = _my_getstr("cuf1", optional=True)
+        self._cup = _my_getstr("cup")
+        self._cuu = _my_getstr("cuu", optional=True)
+        self._cuu1 = _my_getstr("cuu1", optional=True)
+        self._dch1 = _my_getstr("dch1", optional=True)
+        self._dch = _my_getstr("dch", optional=True)
+        self._el = _my_getstr("el")
+        self._hpa = _my_getstr("hpa", optional=True)
+        self._ich = _my_getstr("ich", optional=True)
+        self._ich1 = _my_getstr("ich1", optional=True)
+        self._ind = _my_getstr("ind", optional=True)
+        self._pad = _my_getstr("pad", optional=True)
+        self._ri = _my_getstr("ri", optional=True)
+        self._rmkx = _my_getstr("rmkx", optional=True)
+        self._smkx = _my_getstr("smkx", optional=True)
+
+        self.__setup_movement()
+
+        self.event_queue = EventQueue(self.input_fd, self.encoding)
+        self.cursor_visible = 1
+
+    def more_in_buffer(self) -> bool:
+        return bool(
+            self.input_buffer
+            and self.input_buffer_pos < len(self.input_buffer)
+        )
+
+    def __read(self, n: int) -> bytes:
+        if not self.more_in_buffer():
+            self.input_buffer = os.read(self.input_fd, 10000)
+
+        ret = self.input_buffer[self.input_buffer_pos : self.input_buffer_pos + n]
+        self.input_buffer_pos += len(ret)
+        if self.input_buffer_pos >= len(self.input_buffer):
+            self.input_buffer = b""
+            self.input_buffer_pos = 0
+        return ret
+
+
+    def change_encoding(self, encoding: str) -> None:
+        """
+        Change the encoding used for I/O operations.
+
+        Parameters:
+        - encoding (str): New encoding to use.
+        """
+        self.encoding = encoding
+
+    def refresh(self, screen, c_xy):
+        """
+        Refresh the console screen.
+
+        Parameters:
+        - screen (list): List of strings representing the screen contents.
+        - c_xy (tuple): Cursor position (x, y) on the screen.
+        """
+        cx, cy = c_xy
+        if not self.__gone_tall:
+            while len(self.screen) < min(len(screen), self.height):
+                self.__hide_cursor()
+                self.__move(0, len(self.screen) - 1)
+                self.__write("\n")
+                self.posxy = 0, len(self.screen)
+                self.screen.append("")
+        else:
+            while len(self.screen) < len(screen):
+                self.screen.append("")
+
+        if len(screen) > self.height:
+            self.__gone_tall = 1
+            self.__move = self.__move_tall
+
+        px, py = self.posxy
+        old_offset = offset = self.__offset
+        height = self.height
+
+        # we make sure the cursor is on the screen, and that we're
+        # using all of the screen if we can
+        if cy < offset:
+            offset = cy
+        elif cy >= offset + height:
+            offset = cy - height + 1
+        elif offset > 0 and len(screen) < offset + height:
+            offset = max(len(screen) - height, 0)
+            screen.append("")
+
+        oldscr = self.screen[old_offset : old_offset + height]
+        newscr = screen[offset : offset + height]
+
+        # use hardware scrolling if we have it.
+        if old_offset > offset and self._ri:
+            self.__hide_cursor()
+            self.__write_code(self._cup, 0, 0)
+            self.posxy = 0, old_offset
+            for i in range(old_offset - offset):
+                self.__write_code(self._ri)
+                oldscr.pop(-1)
+                oldscr.insert(0, "")
+        elif old_offset < offset and self._ind:
+            self.__hide_cursor()
+            self.__write_code(self._cup, self.height - 1, 0)
+            self.posxy = 0, old_offset + self.height - 1
+            for i in range(offset - old_offset):
+                self.__write_code(self._ind)
+                oldscr.pop(0)
+                oldscr.append("")
+
+        self.__offset = offset
+
+        for (
+            y,
+            oldline,
+            newline,
+        ) in zip(range(offset, offset + height), oldscr, newscr):
+            if oldline != newline:
+                self.__write_changed_line(y, oldline, newline, px)
+
+        y = len(newscr)
+        while y < len(oldscr):
+            self.__hide_cursor()
+            self.__move(0, y)
+            self.posxy = 0, y
+            self.__write_code(self._el)
+            y += 1
+
+        self.__show_cursor()
+
+        self.screen = screen.copy()
+        self.move_cursor(cx, cy)
+        self.flushoutput()
+
+    def move_cursor(self, x, y):
+        """
+        Move the cursor to the specified position on the screen.
+
+        Parameters:
+        - x (int): X coordinate.
+        - y (int): Y coordinate.
+        """
+        if y < self.__offset or y >= self.__offset + self.height:
+            self.event_queue.insert(Event("scroll", None))
+        else:
+            self.__move(x, y)
+            self.posxy = x, y
+            self.flushoutput()
+
+    def prepare(self):
+        """
+        Prepare the console for input/output operations.
+        """
+        self.__svtermstate = tcgetattr(self.input_fd)
+        raw = self.__svtermstate.copy()
+        raw.iflag &= ~(termios.INPCK | termios.ISTRIP | termios.IXON)
+        raw.oflag &= ~(termios.OPOST)
+        raw.cflag &= ~(termios.CSIZE | termios.PARENB)
+        raw.cflag |= termios.CS8
+        raw.iflag |= termios.BRKINT
+        raw.lflag &= ~(termios.ICANON | termios.ECHO | termios.IEXTEN)
+        raw.lflag |= termios.ISIG
+        raw.cc[termios.VMIN] = 1
+        raw.cc[termios.VTIME] = 0
+        tcsetattr(self.input_fd, termios.TCSADRAIN, raw)
+
+        # In macOS terminal we need to deactivate line wrap via ANSI escape code
+        if platform.system() == "Darwin" and os.getenv("TERM_PROGRAM") == "Apple_Terminal":
+            os.write(self.output_fd, b"\033[?7l")
+
+        self.screen = []
+        self.height, self.width = self.getheightwidth()
+
+        self.__buffer = []
+
+        self.posxy = 0, 0
+        self.__gone_tall = 0
+        self.__move = self.__move_short
+        self.__offset = 0
+
+        self.__maybe_write_code(self._smkx)
+
+        try:
+            self.old_sigwinch = signal.signal(signal.SIGWINCH, self.__sigwinch)
+        except ValueError:
+            pass
+
+        self.__enable_bracketed_paste()
+
+    def restore(self):
+        """
+        Restore the console to the default state
+        """
+        self.__disable_bracketed_paste()
+        self.__maybe_write_code(self._rmkx)
+        self.flushoutput()
+        tcsetattr(self.input_fd, termios.TCSADRAIN, self.__svtermstate)
+
+        if platform.system() == "Darwin" and os.getenv("TERM_PROGRAM") == "Apple_Terminal":
+            os.write(self.output_fd, b"\033[?7h")
+
+        if hasattr(self, "old_sigwinch"):
+            signal.signal(signal.SIGWINCH, self.old_sigwinch)
+            del self.old_sigwinch
+
+    def push_char(self, char: int | bytes) -> None:
+        """
+        Push a character to the console event queue.
+        """
+        trace("push char {char!r}", char=char)
+        self.event_queue.push(char)
+
+    def get_event(self, block: bool = True) -> Event | None:
+        """
+        Get an event from the console event queue.
+
+        Parameters:
+        - block (bool): Whether to block until an event is available.
+
+        Returns:
+        - Event: Event object from the event queue.
+        """
+        if not block and not self.wait(timeout=0):
+            return None
+
+        while self.event_queue.empty():
+            while True:
+                try:
+                    self.push_char(self.__read(1))
+                except OSError as err:
+                    if err.errno == errno.EINTR:
+                        if not self.event_queue.empty():
+                            return self.event_queue.get()
+                        else:
+                            continue
+                    else:
+                        raise
+                else:
+                    break
+        return self.event_queue.get()
+
+    def wait(self, timeout: float | None = None) -> bool:
+        """
+        Wait for events on the console.
+        """
+        return (
+            not self.event_queue.empty()
+            or self.more_in_buffer()
+            or bool(self.pollob.poll(timeout))
+        )
+
+    def set_cursor_vis(self, visible):
+        """
+        Set the visibility of the cursor.
+
+        Parameters:
+        - visible (bool): Visibility flag.
+        """
+        if visible:
+            self.__show_cursor()
+        else:
+            self.__hide_cursor()
+
+    if TIOCGWINSZ:
+
+        def getheightwidth(self):
+            """
+            Get the height and width of the console.
+
+            Returns:
+            - tuple: Height and width of the console.
+            """
+            try:
+                return int(os.environ["LINES"]), int(os.environ["COLUMNS"])
+            except (KeyError, TypeError, ValueError):
+                try:
+                    size = ioctl(self.input_fd, TIOCGWINSZ, b"\000" * 8)
+                except OSError:
+                    return 25, 80
+                height, width = struct.unpack("hhhh", size)[0:2]
+                if not height:
+                    return 25, 80
+                return height, width
+
+    else:
+
+        def getheightwidth(self):
+            """
+            Get the height and width of the console.
+
+            Returns:
+            - tuple: Height and width of the console.
+            """
+            try:
+                return int(os.environ["LINES"]), int(os.environ["COLUMNS"])
+            except (KeyError, TypeError, ValueError):
+                return 25, 80
+
+    def forgetinput(self):
+        """
+        Discard any pending input on the console.
+        """
+        termios.tcflush(self.input_fd, termios.TCIFLUSH)
+
+    def flushoutput(self):
+        """
+        Flush the output buffer.
+        """
+        for text, iscode in self.__buffer:
+            if iscode:
+                self.__tputs(text)
+            else:
+                os.write(self.output_fd, text.encode(self.encoding, "replace"))
+        del self.__buffer[:]
+
+    def finish(self):
+        """
+        Finish console operations and flush the output buffer.
+        """
+        y = len(self.screen) - 1
+        while y >= 0 and not self.screen[y]:
+            y -= 1
+        self.__move(0, min(y, self.height + self.__offset - 1))
+        self.__write("\n\r")
+        self.flushoutput()
+
+    def beep(self):
+        """
+        Emit a beep sound.
+        """
+        self.__maybe_write_code(self._bel)
+        self.flushoutput()
+
+    if FIONREAD:
+
+        def getpending(self):
+            """
+            Get pending events from the console event queue.
+
+            Returns:
+            - Event: Pending event from the event queue.
+            """
+            e = Event("key", "", b"")
+
+            while not self.event_queue.empty():
+                e2 = self.event_queue.get()
+                e.data += e2.data
+                e.raw += e.raw
+
+            amount = struct.unpack("i", ioctl(self.input_fd, FIONREAD, b"\0\0\0\0"))[0]
+            raw = self.__read(amount)
+            data = str(raw, self.encoding, "replace")
+            e.data += data
+            e.raw += raw
+            return e
+
+    else:
+
+        def getpending(self):
+            """
+            Get pending events from the console event queue.
+
+            Returns:
+            - Event: Pending event from the event queue.
+            """
+            e = Event("key", "", b"")
+
+            while not self.event_queue.empty():
+                e2 = self.event_queue.get()
+                e.data += e2.data
+                e.raw += e.raw
+
+            amount = 10000
+            raw = self.__read(amount)
+            data = str(raw, self.encoding, "replace")
+            e.data += data
+            e.raw += raw
+            return e
+
+    def clear(self):
+        """
+        Clear the console screen.
+        """
+        self.__write_code(self._clear)
+        self.__gone_tall = 1
+        self.__move = self.__move_tall
+        self.posxy = 0, 0
+        self.screen = []
+
+    @property
+    def input_hook(self):
+        try:
+            import posix
+        except ImportError:
+            return None
+        if posix._is_inputhook_installed():
+            return posix._inputhook
+
+    def __enable_bracketed_paste(self) -> None:
+        os.write(self.output_fd, b"\x1b[?2004h")
+
+    def __disable_bracketed_paste(self) -> None:
+        os.write(self.output_fd, b"\x1b[?2004l")
+
+    def __setup_movement(self):
+        """
+        Set up the movement functions based on the terminal capabilities.
+        """
+        if 0 and self._hpa:  # hpa don't work in windows telnet :-(
+            self.__move_x = self.__move_x_hpa
+        elif self._cub and self._cuf:
+            self.__move_x = self.__move_x_cub_cuf
+        elif self._cub1 and self._cuf1:
+            self.__move_x = self.__move_x_cub1_cuf1
+        else:
+            raise RuntimeError("insufficient terminal (horizontal)")
+
+        if self._cuu and self._cud:
+            self.__move_y = self.__move_y_cuu_cud
+        elif self._cuu1 and self._cud1:
+            self.__move_y = self.__move_y_cuu1_cud1
+        else:
+            raise RuntimeError("insufficient terminal (vertical)")
+
+        if self._dch1:
+            self.dch1 = self._dch1
+        elif self._dch:
+            self.dch1 = curses.tparm(self._dch, 1)
+        else:
+            self.dch1 = None
+
+        if self._ich1:
+            self.ich1 = self._ich1
+        elif self._ich:
+            self.ich1 = curses.tparm(self._ich, 1)
+        else:
+            self.ich1 = None
+
+        self.__move = self.__move_short
+
+    def __write_changed_line(self, y, oldline, newline, px_coord):
+        # this is frustrating; there's no reason to test (say)
+        # self.dch1 inside the loop -- but alternative ways of
+        # structuring this function are equally painful (I'm trying to
+        # avoid writing code generators these days...)
+        minlen = min(wlen(oldline), wlen(newline))
+        x_pos = 0
+        x_coord = 0
+
+        px_pos = 0
+        j = 0
+        for c in oldline:
+            if j >= px_coord:
+                break
+            j += wlen(c)
+            px_pos += 1
+
+        # reuse the oldline as much as possible, but stop as soon as we
+        # encounter an ESCAPE, because it might be the start of an escape
+        # sequene
+        while (
+            x_coord < minlen
+            and oldline[x_pos] == newline[x_pos]
+            and newline[x_pos] != "\x1b"
+        ):
+            x_coord += wlen(newline[x_pos])
+            x_pos += 1
+
+        # if we need to insert a single character right after the first detected change
+        if oldline[x_pos:] == newline[x_pos + 1 :] and self.ich1:
+            if (
+                y == self.posxy[1]
+                and x_coord > self.posxy[0]
+                and oldline[px_pos:x_pos] == newline[px_pos + 1 : x_pos + 1]
+            ):
+                x_pos = px_pos
+                x_coord = px_coord
+            character_width = wlen(newline[x_pos])
+            self.__move(x_coord, y)
+            self.__write_code(self.ich1)
+            self.__write(newline[x_pos])
+            self.posxy = x_coord + character_width, y
+
+        # if it's a single character change in the middle of the line
+        elif (
+            x_coord < minlen
+            and oldline[x_pos + 1 :] == newline[x_pos + 1 :]
+            and wlen(oldline[x_pos]) == wlen(newline[x_pos])
+        ):
+            character_width = wlen(newline[x_pos])
+            self.__move(x_coord, y)
+            self.__write(newline[x_pos])
+            self.posxy = x_coord + character_width, y
+
+        # if this is the last character to fit in the line and we edit in the middle of the line
+        elif (
+            self.dch1
+            and self.ich1
+            and wlen(newline) == self.width
+            and x_coord < wlen(newline) - 2
+            and newline[x_pos + 1 : -1] == oldline[x_pos:-2]
+        ):
+            self.__hide_cursor()
+            self.__move(self.width - 2, y)
+            self.posxy = self.width - 2, y
+            self.__write_code(self.dch1)
+
+            character_width = wlen(newline[x_pos])
+            self.__move(x_coord, y)
+            self.__write_code(self.ich1)
+            self.__write(newline[x_pos])
+            self.posxy = character_width + 1, y
+
+        else:
+            self.__hide_cursor()
+            self.__move(x_coord, y)
+            if wlen(oldline) > wlen(newline):
+                self.__write_code(self._el)
+            self.__write(newline[x_pos:])
+            self.posxy = wlen(newline), y
+
+        if "\x1b" in newline:
+            # ANSI escape characters are present, so we can't assume
+            # anything about the position of the cursor.  Moving the cursor
+            # to the left margin should work to get to a known position.
+            self.move_cursor(0, y)
+
+    def __write(self, text):
+        self.__buffer.append((text, 0))
+
+    def __write_code(self, fmt, *args):
+        self.__buffer.append((curses.tparm(fmt, *args), 1))
+
+    def __maybe_write_code(self, fmt, *args):
+        if fmt:
+            self.__write_code(fmt, *args)
+
+    def __move_y_cuu1_cud1(self, y):
+        assert self._cud1 is not None
+        assert self._cuu1 is not None
+        dy = y - self.posxy[1]
+        if dy > 0:
+            self.__write_code(dy * self._cud1)
+        elif dy < 0:
+            self.__write_code((-dy) * self._cuu1)
+
+    def __move_y_cuu_cud(self, y):
+        dy = y - self.posxy[1]
+        if dy > 0:
+            self.__write_code(self._cud, dy)
+        elif dy < 0:
+            self.__write_code(self._cuu, -dy)
+
+    def __move_x_hpa(self, x: int) -> None:
+        if x != self.posxy[0]:
+            self.__write_code(self._hpa, x)
+
+    def __move_x_cub1_cuf1(self, x: int) -> None:
+        assert self._cuf1 is not None
+        assert self._cub1 is not None
+        dx = x - self.posxy[0]
+        if dx > 0:
+            self.__write_code(self._cuf1 * dx)
+        elif dx < 0:
+            self.__write_code(self._cub1 * (-dx))
+
+    def __move_x_cub_cuf(self, x: int) -> None:
+        dx = x - self.posxy[0]
+        if dx > 0:
+            self.__write_code(self._cuf, dx)
+        elif dx < 0:
+            self.__write_code(self._cub, -dx)
+
+    def __move_short(self, x, y):
+        self.__move_x(x)
+        self.__move_y(y)
+
+    def __move_tall(self, x, y):
+        assert 0 <= y - self.__offset < self.height, y - self.__offset
+        self.__write_code(self._cup, y - self.__offset, x)
+
+    def __sigwinch(self, signum, frame):
+        self.height, self.width = self.getheightwidth()
+        self.event_queue.insert(Event("resize", None))
+
+    def __hide_cursor(self):
+        if self.cursor_visible:
+            self.__maybe_write_code(self._civis)
+            self.cursor_visible = 0
+
+    def __show_cursor(self):
+        if not self.cursor_visible:
+            self.__maybe_write_code(self._cnorm)
+            self.cursor_visible = 1
+
+    def repaint(self):
+        if not self.__gone_tall:
+            self.posxy = 0, self.posxy[1]
+            self.__write("\r")
+            ns = len(self.screen) * ["\000" * self.width]
+            self.screen = ns
+        else:
+            self.posxy = 0, self.__offset
+            self.__move(0, self.__offset)
+            ns = self.height * ["\000" * self.width]
+            self.screen = ns
+
+    def __tputs(self, fmt, prog=delayprog):
+        """A Python implementation of the curses tputs function; the
+        curses one can't really be wrapped in a sane manner.
+
+        I have the strong suspicion that this is complexity that
+        will never do anyone any good."""
+        # using .get() means that things will blow up
+        # only if the bps is actually needed (which I'm
+        # betting is pretty unlkely)
+        bps = ratedict.get(self.__svtermstate.ospeed)
+        while 1:
+            m = prog.search(fmt)
+            if not m:
+                os.write(self.output_fd, fmt)
+                break
+            x, y = m.span()
+            os.write(self.output_fd, fmt[:x])
+            fmt = fmt[y:]
+            delay = int(m.group(1))
+            if b"*" in m.group(2):
+                delay *= self.height
+            if self._pad and bps is not None:
+                nchars = (bps * delay) / 1000
+                os.write(self.output_fd, self._pad * nchars)
+            else:
+                time.sleep(float(delay) / 1000.0)
--- a/Lib/_pyrepl/unix_eventqueue.py
+++ b/Lib/_pyrepl/unix_eventqueue.py
@@ -0,0 +1,152 @@
+#   Copyright 2000-2008 Michael Hudson-Doyle <micahel@gmail.com>
+#                       Armin Rigo
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from collections import deque
+
+from . import keymap
+from .console import Event
+from . import curses
+from .trace import trace
+from termios import tcgetattr, VERASE
+import os
+
+
+# Mapping of human-readable key names to their terminal-specific codes
+TERMINAL_KEYNAMES = {
+    "delete": "kdch1",
+    "down": "kcud1",
+    "end": "kend",
+    "enter": "kent",
+    "home": "khome",
+    "insert": "kich1",
+    "left": "kcub1",
+    "page down": "knp",
+    "page up": "kpp",
+    "right": "kcuf1",
+    "up": "kcuu1",
+}
+
+
+# Function keys F1-F20 mapping
+TERMINAL_KEYNAMES.update(("f%d" % i, "kf%d" % i) for i in range(1, 21))
+
+# Known CTRL-arrow keycodes
+CTRL_ARROW_KEYCODES= {
+    # for xterm, gnome-terminal, xfce terminal, etc.
+    b'\033[1;5D': 'ctrl left',
+    b'\033[1;5C': 'ctrl right',
+    # for rxvt
+    b'\033Od': 'ctrl left',
+    b'\033Oc': 'ctrl right',
+}
+
+def get_terminal_keycodes() -> dict[bytes, str]:
+    """
+    Generates a dictionary mapping terminal keycodes to human-readable names.
+    """
+    keycodes = {}
+    for key, terminal_code in TERMINAL_KEYNAMES.items():
+        keycode = curses.tigetstr(terminal_code)
+        trace('key {key} tiname {terminal_code} keycode {keycode!r}', **locals())
+        if keycode:
+            keycodes[keycode] = key
+    keycodes.update(CTRL_ARROW_KEYCODES)
+    return keycodes
+
+class EventQueue:
+    def __init__(self, fd: int, encoding: str) -> None:
+        self.keycodes = get_terminal_keycodes()
+        if os.isatty(fd):
+            backspace = tcgetattr(fd)[6][VERASE]
+            self.keycodes[backspace] = "backspace"
+        self.compiled_keymap = keymap.compile_keymap(self.keycodes)
+        self.keymap = self.compiled_keymap
+        trace("keymap {k!r}", k=self.keymap)
+        self.encoding = encoding
+        self.events: deque[Event] = deque()
+        self.buf = bytearray()
+
+    def get(self) -> Event | None:
+        """
+        Retrieves the next event from the queue.
+        """
+        if self.events:
+            return self.events.popleft()
+        else:
+            return None
+
+    def empty(self) -> bool:
+        """
+        Checks if the queue is empty.
+        """
+        return not self.events
+
+    def flush_buf(self) -> bytearray:
+        """
+        Flushes the buffer and returns its contents.
+        """
+        old = self.buf
+        self.buf = bytearray()
+        return old
+
+    def insert(self, event: Event) -> None:
+        """
+        Inserts an event into the queue.
+        """
+        trace('added event {event}', event=event)
+        self.events.append(event)
+
+    def push(self, char: int | bytes) -> None:
+        """
+        Processes a character by updating the buffer and handling special key mappings.
+        """
+        ord_char = char if isinstance(char, int) else ord(char)
+        char = bytes(bytearray((ord_char,)))
+        self.buf.append(ord_char)
+        if char in self.keymap:
+            if self.keymap is self.compiled_keymap:
+                #sanity check, buffer is empty when a special key comes
+                assert len(self.buf) == 1
+            k = self.keymap[char]
+            trace('found map {k!r}', k=k)
+            if isinstance(k, dict):
+                self.keymap = k
+            else:
+                self.insert(Event('key', k, self.flush_buf()))
+                self.keymap = self.compiled_keymap
+
+        elif self.buf and self.buf[0] == 27:  # escape
+            # escape sequence not recognized by our keymap: propagate it
+            # outside so that i can be recognized as an M-... key (see also
+            # the docstring in keymap.py
+            trace('unrecognized escape sequence, propagating...')
+            self.keymap = self.compiled_keymap
+            self.insert(Event('key', '\033', bytearray(b'\033')))
+            for _c in self.flush_buf()[1:]:
+                self.push(_c)
+
+        else:
+            try:
+                decoded = bytes(self.buf).decode(self.encoding)
+            except UnicodeError:
+                return
+            else:
+                self.insert(Event('key', decoded, self.flush_buf()))
+            self.keymap = self.compiled_keymap
--- a/Lib/_pyrepl/utils.py
+++ b/Lib/_pyrepl/utils.py
@@ -0,0 +1,25 @@
+import re
+import unicodedata
+import functools
+
+ANSI_ESCAPE_SEQUENCE = re.compile(r"\x1b\[[ -@]*[A-~]")
+
+
+@functools.cache
+def str_width(c: str) -> int:
+    if ord(c) < 128:
+        return 1
+    w = unicodedata.east_asian_width(c)
+    if w in ('N', 'Na', 'H', 'A'):
+        return 1
+    return 2
+
+
+def wlen(s: str) -> int:
+    if len(s) == 1 and s != '\x1a':
+        return str_width(s)
+    length = sum(str_width(i) for i in s)
+    # remove lengths of any escape sequences
+    sequence = ANSI_ESCAPE_SEQUENCE.findall(s)
+    ctrl_z_cnt = s.count('\x1a')
+    return length - sum(len(i) for i in sequence) + ctrl_z_cnt
--- a/Lib/_pyrepl/windows_console.py
+++ b/Lib/_pyrepl/windows_console.py
@@ -0,0 +1,618 @@
+#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
+#
+#                        All Rights Reserved
+#
+#
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose is hereby granted without fee,
+# provided that the above copyright notice appear in all copies and
+# that both that copyright notice and this permission notice appear in
+# supporting documentation.
+#
+# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
+# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
+# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from __future__ import annotations
+
+import io
+import os
+import sys
+import time
+import msvcrt
+
+from collections import deque
+import ctypes
+from ctypes.wintypes import (
+    _COORD,
+    WORD,
+    SMALL_RECT,
+    BOOL,
+    HANDLE,
+    CHAR,
+    DWORD,
+    WCHAR,
+    SHORT,
+)
+from ctypes import Structure, POINTER, Union
+from .console import Event, Console
+from .trace import trace
+from .utils import wlen
+
+try:
+    from ctypes import GetLastError, WinDLL, windll, WinError  # type: ignore[attr-defined]
+except:
+    # Keep MyPy happy off Windows
+    from ctypes import CDLL as WinDLL, cdll as windll
+
+    def GetLastError() -> int:
+        return 42
+
+    class WinError(OSError):  # type: ignore[no-redef]
+        def __init__(self, err: int | None, descr: str | None = None) -> None:
+            self.err = err
+            self.descr = descr
+
+
+TYPE_CHECKING = False
+
+if TYPE_CHECKING:
+    from typing import IO
+
+# Virtual-Key Codes: https://learn.microsoft.com/en-us/windows/win32/inputdev/virtual-key-codes
+VK_MAP: dict[int, str] = {
+    0x23: "end",  # VK_END
+    0x24: "home",  # VK_HOME
+    0x25: "left",  # VK_LEFT
+    0x26: "up",  # VK_UP
+    0x27: "right",  # VK_RIGHT
+    0x28: "down",  # VK_DOWN
+    0x2E: "delete",  # VK_DELETE
+    0x70: "f1",  # VK_F1
+    0x71: "f2",  # VK_F2
+    0x72: "f3",  # VK_F3
+    0x73: "f4",  # VK_F4
+    0x74: "f5",  # VK_F5
+    0x75: "f6",  # VK_F6
+    0x76: "f7",  # VK_F7
+    0x77: "f8",  # VK_F8
+    0x78: "f9",  # VK_F9
+    0x79: "f10",  # VK_F10
+    0x7A: "f11",  # VK_F11
+    0x7B: "f12",  # VK_F12
+    0x7C: "f13",  # VK_F13
+    0x7D: "f14",  # VK_F14
+    0x7E: "f15",  # VK_F15
+    0x7F: "f16",  # VK_F16
+    0x80: "f17",  # VK_F17
+    0x81: "f18",  # VK_F18
+    0x82: "f19",  # VK_F19
+    0x83: "f20",  # VK_F20
+}
+
+# Console escape codes: https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences
+ERASE_IN_LINE = "\x1b[K"
+MOVE_LEFT = "\x1b[{}D"
+MOVE_RIGHT = "\x1b[{}C"
+MOVE_UP = "\x1b[{}A"
+MOVE_DOWN = "\x1b[{}B"
+CLEAR = "\x1b[H\x1b[J"
+
+
+class _error(Exception):
+    pass
+
+
+class WindowsConsole(Console):
+    def __init__(
+        self,
+        f_in: IO[bytes] | int = 0,
+        f_out: IO[bytes] | int = 1,
+        term: str = "",
+        encoding: str = "",
+    ):
+        super().__init__(f_in, f_out, term, encoding)
+
+        SetConsoleMode(
+            OutHandle,
+            ENABLE_WRAP_AT_EOL_OUTPUT
+            | ENABLE_PROCESSED_OUTPUT
+            | ENABLE_VIRTUAL_TERMINAL_PROCESSING,
+        )
+        self.screen: list[str] = []
+        self.width = 80
+        self.height = 25
+        self.__offset = 0
+        self.event_queue: deque[Event] = deque()
+        try:
+            self.out = io._WindowsConsoleIO(self.output_fd, "w")  # type: ignore[attr-defined]
+        except ValueError:
+            # Console I/O is redirected, fallback...
+            self.out = None
+
+    def refresh(self, screen: list[str], c_xy: tuple[int, int]) -> None:
+        """
+        Refresh the console screen.
+
+        Parameters:
+        - screen (list): List of strings representing the screen contents.
+        - c_xy (tuple): Cursor position (x, y) on the screen.
+        """
+        cx, cy = c_xy
+
+        while len(self.screen) < min(len(screen), self.height):
+            self._hide_cursor()
+            self._move_relative(0, len(self.screen) - 1)
+            self.__write("\n")
+            self.posxy = 0, len(self.screen)
+            self.screen.append("")
+
+        px, py = self.posxy
+        old_offset = offset = self.__offset
+        height = self.height
+
+        # we make sure the cursor is on the screen, and that we're
+        # using all of the screen if we can
+        if cy < offset:
+            offset = cy
+        elif cy >= offset + height:
+            offset = cy - height + 1
+            scroll_lines = offset - old_offset
+
+            # Scrolling the buffer as the current input is greater than the visible
+            # portion of the window.  We need to scroll the visible portion and the
+            # entire history
+            self._scroll(scroll_lines, self._getscrollbacksize())
+            self.posxy = self.posxy[0], self.posxy[1] + scroll_lines
+            self.__offset += scroll_lines
+
+            for i in range(scroll_lines):
+                self.screen.append("")
+        elif offset > 0 and len(screen) < offset + height:
+            offset = max(len(screen) - height, 0)
+            screen.append("")
+
+        oldscr = self.screen[old_offset : old_offset + height]
+        newscr = screen[offset : offset + height]
+
+        self.__offset = offset
+
+        self._hide_cursor()
+        for (
+            y,
+            oldline,
+            newline,
+        ) in zip(range(offset, offset + height), oldscr, newscr):
+            if oldline != newline:
+                self.__write_changed_line(y, oldline, newline, px)
+
+        y = len(newscr)
+        while y < len(oldscr):
+            self._move_relative(0, y)
+            self.posxy = 0, y
+            self._erase_to_end()
+            y += 1
+
+        self._show_cursor()
+
+        self.screen = screen
+        self.move_cursor(cx, cy)
+
+    @property
+    def input_hook(self):
+        try:
+            import nt
+        except ImportError:
+            return None
+        if nt._is_inputhook_installed():
+            return nt._inputhook
+
+    def __write_changed_line(
+        self, y: int, oldline: str, newline: str, px_coord: int
+    ) -> None:
+        # this is frustrating; there's no reason to test (say)
+        # self.dch1 inside the loop -- but alternative ways of
+        # structuring this function are equally painful (I'm trying to
+        # avoid writing code generators these days...)
+        minlen = min(wlen(oldline), wlen(newline))
+        x_pos = 0
+        x_coord = 0
+
+        px_pos = 0
+        j = 0
+        for c in oldline:
+            if j >= px_coord:
+                break
+            j += wlen(c)
+            px_pos += 1
+
+        # reuse the oldline as much as possible, but stop as soon as we
+        # encounter an ESCAPE, because it might be the start of an escape
+        # sequene
+        while (
+            x_coord < minlen
+            and oldline[x_pos] == newline[x_pos]
+            and newline[x_pos] != "\x1b"
+        ):
+            x_coord += wlen(newline[x_pos])
+            x_pos += 1
+
+        self._hide_cursor()
+        self._move_relative(x_coord, y)
+        if wlen(oldline) > wlen(newline):
+            self._erase_to_end()
+
+        self.__write(newline[x_pos:])
+        if wlen(newline) == self.width:
+            # If we wrapped we want to start at the next line
+            self._move_relative(0, y + 1)
+            self.posxy = 0, y + 1
+        else:
+            self.posxy = wlen(newline), y
+
+            if "\x1b" in newline or y != self.posxy[1] or '\x1a' in newline:
+                # ANSI escape characters are present, so we can't assume
+                # anything about the position of the cursor.  Moving the cursor
+                # to the left margin should work to get to a known position.
+                self.move_cursor(0, y)
+
+    def _scroll(
+        self, top: int, bottom: int, left: int | None = None, right: int | None = None
+    ) -> None:
+        scroll_rect = SMALL_RECT()
+        scroll_rect.Top = SHORT(top)
+        scroll_rect.Bottom = SHORT(bottom)
+        scroll_rect.Left = SHORT(0 if left is None else left)
+        scroll_rect.Right = SHORT(
+            self.getheightwidth()[1] - 1 if right is None else right
+        )
+        destination_origin = _COORD()
+        fill_info = CHAR_INFO()
+        fill_info.UnicodeChar = " "
+
+        if not ScrollConsoleScreenBuffer(
+            OutHandle, scroll_rect, None, destination_origin, fill_info
+        ):
+            raise WinError(GetLastError())
+
+    def _hide_cursor(self):
+        self.__write("\x1b[?25l")
+
+    def _show_cursor(self):
+        self.__write("\x1b[?25h")
+
+    def _enable_blinking(self):
+        self.__write("\x1b[?12h")
+
+    def _disable_blinking(self):
+        self.__write("\x1b[?12l")
+
+    def __write(self, text: str) -> None:
+        if "\x1a" in text:
+            text = ''.join(["^Z" if x == '\x1a' else x for x in text])
+
+        if self.out is not None:
+            self.out.write(text.encode(self.encoding, "replace"))
+            self.out.flush()
+        else:
+            os.write(self.output_fd, text.encode(self.encoding, "replace"))
+
+    @property
+    def screen_xy(self) -> tuple[int, int]:
+        info = CONSOLE_SCREEN_BUFFER_INFO()
+        if not GetConsoleScreenBufferInfo(OutHandle, info):
+            raise WinError(GetLastError())
+        return info.dwCursorPosition.X, info.dwCursorPosition.Y
+
+    def _erase_to_end(self) -> None:
+        self.__write(ERASE_IN_LINE)
+
+    def prepare(self) -> None:
+        trace("prepare")
+        self.screen = []
+        self.height, self.width = self.getheightwidth()
+
+        self.posxy = 0, 0
+        self.__gone_tall = 0
+        self.__offset = 0
+
+    def restore(self) -> None:
+        pass
+
+    def _move_relative(self, x: int, y: int) -> None:
+        """Moves relative to the current posxy"""
+        dx = x - self.posxy[0]
+        dy = y - self.posxy[1]
+        if dx < 0:
+            self.__write(MOVE_LEFT.format(-dx))
+        elif dx > 0:
+            self.__write(MOVE_RIGHT.format(dx))
+
+        if dy < 0:
+            self.__write(MOVE_UP.format(-dy))
+        elif dy > 0:
+            self.__write(MOVE_DOWN.format(dy))
+
+    def move_cursor(self, x: int, y: int) -> None:
+        if x < 0 or y < 0:
+            raise ValueError(f"Bad cursor position {x}, {y}")
+
+        if y < self.__offset or y >= self.__offset + self.height:
+            self.event_queue.insert(0, Event("scroll", ""))
+        else:
+            self._move_relative(x, y)
+            self.posxy = x, y
+
+    def set_cursor_vis(self, visible: bool) -> None:
+        if visible:
+            self._show_cursor()
+        else:
+            self._hide_cursor()
+
+    def getheightwidth(self) -> tuple[int, int]:
+        """Return (height, width) where height and width are the height
+        and width of the terminal window in characters."""
+        info = CONSOLE_SCREEN_BUFFER_INFO()
+        if not GetConsoleScreenBufferInfo(OutHandle, info):
+            raise WinError(GetLastError())
+        return (
+            info.srWindow.Bottom - info.srWindow.Top + 1,
+            info.srWindow.Right - info.srWindow.Left + 1,
+        )
+
+    def _getscrollbacksize(self) -> int:
+        info = CONSOLE_SCREEN_BUFFER_INFO()
+        if not GetConsoleScreenBufferInfo(OutHandle, info):
+            raise WinError(GetLastError())
+
+        return info.srWindow.Bottom  # type: ignore[no-any-return]
+
+    def _read_input(self, block: bool = True) -> INPUT_RECORD | None:
+        if not block:
+            events = DWORD()
+            if not GetNumberOfConsoleInputEvents(InHandle, events):
+                raise WinError(GetLastError())
+            if not events.value:
+                return None
+
+        rec = INPUT_RECORD()
+        read = DWORD()
+        if not ReadConsoleInput(InHandle, rec, 1, read):
+            raise WinError(GetLastError())
+
+        return rec
+
+    def get_event(self, block: bool = True) -> Event | None:
+        """Return an Event instance.  Returns None if |block| is false
+        and there is no event pending, otherwise waits for the
+        completion of an event."""
+        if self.event_queue:
+            return self.event_queue.pop()
+
+        while True:
+            rec = self._read_input(block)
+            if rec is None:
+                return None
+
+            if rec.EventType == WINDOW_BUFFER_SIZE_EVENT:
+                return Event("resize", "")
+
+            if rec.EventType != KEY_EVENT or not rec.Event.KeyEvent.bKeyDown:
+                # Only process keys and keydown events
+                if block:
+                    continue
+                return None
+
+            key = rec.Event.KeyEvent.uChar.UnicodeChar
+
+            if rec.Event.KeyEvent.uChar.UnicodeChar == "\r":
+                # Make enter make unix-like
+                return Event(evt="key", data="\n", raw=b"\n")
+            elif rec.Event.KeyEvent.wVirtualKeyCode == 8:
+                # Turn backspace directly into the command
+                return Event(
+                    evt="key",
+                    data="backspace",
+                    raw=rec.Event.KeyEvent.uChar.UnicodeChar,
+                )
+            elif rec.Event.KeyEvent.uChar.UnicodeChar == "\x00":
+                # Handle special keys like arrow keys and translate them into the appropriate command
+                code = VK_MAP.get(rec.Event.KeyEvent.wVirtualKeyCode)
+                if code:
+                    return Event(
+                        evt="key", data=code, raw=rec.Event.KeyEvent.uChar.UnicodeChar
+                    )
+                if block:
+                    continue
+
+                return None
+
+            return Event(evt="key", data=key, raw=rec.Event.KeyEvent.uChar.UnicodeChar)
+
+    def push_char(self, char: int | bytes) -> None:
+        """
+        Push a character to the console event queue.
+        """
+        raise NotImplementedError("push_char not supported on Windows")
+
+    def beep(self) -> None:
+        self.__write("\x07")
+
+    def clear(self) -> None:
+        """Wipe the screen"""
+        self.__write(CLEAR)
+        self.posxy = 0, 0
+        self.screen = [""]
+
+    def finish(self) -> None:
+        """Move the cursor to the end of the display and otherwise get
+        ready for end.  XXX could be merged with restore?  Hmm."""
+        y = len(self.screen) - 1
+        while y >= 0 and not self.screen[y]:
+            y -= 1
+        self._move_relative(0, min(y, self.height + self.__offset - 1))
+        self.__write("\r\n")
+
+    def flushoutput(self) -> None:
+        """Flush all output to the screen (assuming there's some
+        buffering going on somewhere).
+
+        All output on Windows is unbuffered so this is a nop"""
+        pass
+
+    def forgetinput(self) -> None:
+        """Forget all pending, but not yet processed input."""
+        if not FlushConsoleInputBuffer(InHandle):
+            raise WinError(GetLastError())
+
+    def getpending(self) -> Event:
+        """Return the characters that have been typed but not yet
+        processed."""
+        return Event("key", "", b"")
+
+    def wait(self, timeout: float | None) -> bool:
+        """Wait for an event."""
+        # Poor man's Windows select loop
+        start_time = time.time()
+        while True:
+            if msvcrt.kbhit(): # type: ignore[attr-defined]
+                return True
+            if timeout and time.time() - start_time > timeout / 1000:
+                return False
+            time.sleep(0.01)
+
+    def repaint(self) -> None:
+        raise NotImplementedError("No repaint support")
+
+
+# Windows interop
+class CONSOLE_SCREEN_BUFFER_INFO(Structure):
+    _fields_ = [
+        ("dwSize", _COORD),
+        ("dwCursorPosition", _COORD),
+        ("wAttributes", WORD),
+        ("srWindow", SMALL_RECT),
+        ("dwMaximumWindowSize", _COORD),
+    ]
+
+
+class CONSOLE_CURSOR_INFO(Structure):
+    _fields_ = [
+        ("dwSize", DWORD),
+        ("bVisible", BOOL),
+    ]
+
+
+class CHAR_INFO(Structure):
+    _fields_ = [
+        ("UnicodeChar", WCHAR),
+        ("Attributes", WORD),
+    ]
+
+
+class Char(Union):
+    _fields_ = [
+        ("UnicodeChar", WCHAR),
+        ("Char", CHAR),
+    ]
+
+
+class KeyEvent(ctypes.Structure):
+    _fields_ = [
+        ("bKeyDown", BOOL),
+        ("wRepeatCount", WORD),
+        ("wVirtualKeyCode", WORD),
+        ("wVirtualScanCode", WORD),
+        ("uChar", Char),
+        ("dwControlKeyState", DWORD),
+    ]
+
+
+class WindowsBufferSizeEvent(ctypes.Structure):
+    _fields_ = [("dwSize", _COORD)]
+
+
+class ConsoleEvent(ctypes.Union):
+    _fields_ = [
+        ("KeyEvent", KeyEvent),
+        ("WindowsBufferSizeEvent", WindowsBufferSizeEvent),
+    ]
+
+
+class INPUT_RECORD(Structure):
+    _fields_ = [("EventType", WORD), ("Event", ConsoleEvent)]
+
+
+KEY_EVENT = 0x01
+FOCUS_EVENT = 0x10
+MENU_EVENT = 0x08
+MOUSE_EVENT = 0x02
+WINDOW_BUFFER_SIZE_EVENT = 0x04
+
+ENABLE_PROCESSED_OUTPUT = 0x01
+ENABLE_WRAP_AT_EOL_OUTPUT = 0x02
+ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x04
+
+STD_INPUT_HANDLE = -10
+STD_OUTPUT_HANDLE = -11
+
+if sys.platform == "win32":
+    _KERNEL32 = WinDLL("kernel32", use_last_error=True)
+
+    GetStdHandle = windll.kernel32.GetStdHandle
+    GetStdHandle.argtypes = [DWORD]
+    GetStdHandle.restype = HANDLE
+
+    GetConsoleScreenBufferInfo = _KERNEL32.GetConsoleScreenBufferInfo
+    GetConsoleScreenBufferInfo.argtypes = [
+        HANDLE,
+        ctypes.POINTER(CONSOLE_SCREEN_BUFFER_INFO),
+    ]
+    GetConsoleScreenBufferInfo.restype = BOOL
+
+    ScrollConsoleScreenBuffer = _KERNEL32.ScrollConsoleScreenBufferW
+    ScrollConsoleScreenBuffer.argtypes = [
+        HANDLE,
+        POINTER(SMALL_RECT),
+        POINTER(SMALL_RECT),
+        _COORD,
+        POINTER(CHAR_INFO),
+    ]
+    ScrollConsoleScreenBuffer.restype = BOOL
+
+    SetConsoleMode = _KERNEL32.SetConsoleMode
+    SetConsoleMode.argtypes = [HANDLE, DWORD]
+    SetConsoleMode.restype = BOOL
+
+    ReadConsoleInput = _KERNEL32.ReadConsoleInputW
+    ReadConsoleInput.argtypes = [HANDLE, POINTER(INPUT_RECORD), DWORD, POINTER(DWORD)]
+    ReadConsoleInput.restype = BOOL
+
+    GetNumberOfConsoleInputEvents = _KERNEL32.GetNumberOfConsoleInputEvents
+    GetNumberOfConsoleInputEvents.argtypes = [HANDLE, POINTER(DWORD)]
+    GetNumberOfConsoleInputEvents.restype = BOOL
+
+    FlushConsoleInputBuffer = _KERNEL32.FlushConsoleInputBuffer
+    FlushConsoleInputBuffer.argtypes = [HANDLE]
+    FlushConsoleInputBuffer.restype = BOOL
+
+    OutHandle = GetStdHandle(STD_OUTPUT_HANDLE)
+    InHandle = GetStdHandle(STD_INPUT_HANDLE)
+else:
+
+    def _win_only(*args, **kwargs):
+        raise NotImplementedError("Windows only")
+
+    GetStdHandle = _win_only
+    GetConsoleScreenBufferInfo = _win_only
+    ScrollConsoleScreenBuffer = _win_only
+    SetConsoleMode = _win_only
+    ReadConsoleInput = _win_only
+    GetNumberOfConsoleInputEvents = _win_only
+    FlushConsoleInputBuffer = _win_only
+    OutHandle = 0
+    InHandle = 0
--- a/Lib/_sitebuiltins.py
+++ b/Lib/_sitebuiltins.py
@@ -10,7 +10,6 @@ The objects used by the site module to add custom builtins.

 import sys

-
 class Quitter(object):
    def __init__(self, name, eof):
        self.name = name
@@ -48,7 +47,7 @@ class _Printer(object):
        data = None
        for filename in self.__filenames:
            try:
-                with open(filename, "r") as fp:
+                with open(filename, encoding='utf-8') as fp:
                    data = fp.read()
                break
            except OSError:
--- a/Lib/_strptime.py
+++ b/Lib/_strptime.py
@@ -0,0 +1,800 @@
+"""Strptime-related classes and functions.
+
+CLASSES:
+    LocaleTime -- Discovers and stores locale-specific time information
+    TimeRE -- Creates regexes for pattern matching a string of text containing
+                time information
+
+FUNCTIONS:
+    _getlang -- Figure out what language is being used for the locale
+    strptime -- Calculates the time struct represented by the passed-in string
+
+"""
+import os
+import time
+import locale
+import calendar
+import re
+from re import compile as re_compile
+from re import sub as re_sub
+from re import IGNORECASE
+from re import escape as re_escape
+from datetime import (date as datetime_date,
+                      timedelta as datetime_timedelta,
+                      timezone as datetime_timezone)
+from _thread import allocate_lock as _thread_allocate_lock
+
+__all__ = []
+
+def _getlang():
+    # Figure out what the current language is set to.
+    return locale.getlocale(locale.LC_TIME)
+
+def _findall(haystack, needle):
+    # Find all positions of needle in haystack.
+    if not needle:
+        return
+    i = 0
+    while True:
+        i = haystack.find(needle, i)
+        if i < 0:
+            break
+        yield i
+        i += len(needle)
+
+def _fixmonths(months):
+    yield from months
+    # The lower case of 'İ' ('\u0130') is 'i\u0307'.
+    # The re module only supports 1-to-1 character matching in
+    # case-insensitive mode.
+    for s in months:
+        if 'i\u0307' in s:
+            yield s.replace('i\u0307', '\u0130')
+
+lzh_TW_alt_digits = (
+    # 〇:一:二:三:四:五:六:七:八:九
+    '\u3007', '\u4e00', '\u4e8c', '\u4e09', '\u56db',
+    '\u4e94', '\u516d', '\u4e03', '\u516b', '\u4e5d',
+    # 十:十一:十二:十三:十四:十五:十六:十七:十八:十九
+    '\u5341', '\u5341\u4e00', '\u5341\u4e8c', '\u5341\u4e09', '\u5341\u56db',
+    '\u5341\u4e94', '\u5341\u516d', '\u5341\u4e03', '\u5341\u516b', '\u5341\u4e5d',
+    # 廿:廿一:廿二:廿三:廿四:廿五:廿六:廿七:廿八:廿九
+    '\u5eff', '\u5eff\u4e00', '\u5eff\u4e8c', '\u5eff\u4e09', '\u5eff\u56db',
+    '\u5eff\u4e94', '\u5eff\u516d', '\u5eff\u4e03', '\u5eff\u516b', '\u5eff\u4e5d',
+    # 卅:卅一
+    '\u5345', '\u5345\u4e00')
+
+
+class LocaleTime(object):
+    """Stores and handles locale-specific information related to time.
+
+    ATTRIBUTES:
+        f_weekday -- full weekday names (7-item list)
+        a_weekday -- abbreviated weekday names (7-item list)
+        f_month -- full month names (13-item list; dummy value in [0], which
+                    is added by code)
+        a_month -- abbreviated month names (13-item list, dummy value in
+                    [0], which is added by code)
+        am_pm -- AM/PM representation (2-item list)
+        LC_date_time -- format string for date/time representation (string)
+        LC_date -- format string for date representation (string)
+        LC_time -- format string for time representation (string)
+        timezone -- daylight- and non-daylight-savings timezone representation
+                    (2-item list of sets)
+        lang -- Language used by instance (2-item tuple)
+    """
+
+    def __init__(self):
+        """Set all attributes.
+
+        Order of methods called matters for dependency reasons.
+
+        The locale language is set at the offset and then checked again before
+        exiting.  This is to make sure that the attributes were not set with a
+        mix of information from more than one locale.  This would most likely
+        happen when using threads where one thread calls a locale-dependent
+        function while another thread changes the locale while the function in
+        the other thread is still running.  Proper coding would call for
+        locks to prevent changing the locale while locale-dependent code is
+        running.  The check here is done in case someone does not think about
+        doing this.
+
+        Only other possible issue is if someone changed the timezone and did
+        not call tz.tzset .  That is an issue for the programmer, though,
+        since changing the timezone is worthless without that call.
+
+        """
+        self.lang = _getlang()
+        self.__calc_weekday()
+        self.__calc_month()
+        self.__calc_am_pm()
+        self.__calc_alt_digits()
+        self.__calc_timezone()
+        self.__calc_date_time()
+        if _getlang() != self.lang:
+            raise ValueError("locale changed during initialization")
+        if time.tzname != self.tzname or time.daylight != self.daylight:
+            raise ValueError("timezone changed during initialization")
+
+    def __calc_weekday(self):
+        # Set self.a_weekday and self.f_weekday using the calendar
+        # module.
+        a_weekday = [calendar.day_abbr[i].lower() for i in range(7)]
+        f_weekday = [calendar.day_name[i].lower() for i in range(7)]
+        self.a_weekday = a_weekday
+        self.f_weekday = f_weekday
+
+    def __calc_month(self):
+        # Set self.f_month and self.a_month using the calendar module.
+        a_month = [calendar.month_abbr[i].lower() for i in range(13)]
+        f_month = [calendar.month_name[i].lower() for i in range(13)]
+        self.a_month = a_month
+        self.f_month = f_month
+
+    def __calc_am_pm(self):
+        # Set self.am_pm by using time.strftime().
+
+        # The magic date (1999,3,17,hour,44,55,2,76,0) is not really that
+        # magical; just happened to have used it everywhere else where a
+        # static date was needed.
+        am_pm = []
+        for hour in (1, 22):
+            time_tuple = time.struct_time((1999,3,17,hour,44,55,2,76,0))
+            # br_FR has AM/PM info (' ',' ').
+            am_pm.append(time.strftime("%p", time_tuple).lower().strip())
+        self.am_pm = am_pm
+
+    def __calc_alt_digits(self):
+        # Set self.LC_alt_digits by using time.strftime().
+
+        # The magic data should contain all decimal digits.
+        time_tuple = time.struct_time((1998, 1, 27, 10, 43, 56, 1, 27, 0))
+        s = time.strftime("%x%X", time_tuple)
+        if s.isascii():
+            # Fast path -- all digits are ASCII.
+            self.LC_alt_digits = ()
+            return
+
+        digits = ''.join(sorted(set(re.findall(r'\d', s))))
+        if len(digits) == 10 and ord(digits[-1]) == ord(digits[0]) + 9:
+            # All 10 decimal digits from the same set.
+            if digits.isascii():
+                # All digits are ASCII.
+                self.LC_alt_digits = ()
+                return
+
+            self.LC_alt_digits = [a + b for a in digits for b in digits]
+            # Test whether the numbers contain leading zero.
+            time_tuple2 = time.struct_time((2000, 1, 1, 1, 1, 1, 5, 1, 0))
+            if self.LC_alt_digits[1] not in time.strftime("%x %X", time_tuple2):
+                self.LC_alt_digits[:10] = digits
+            return
+
+        # Either non-Gregorian calendar or non-decimal numbers.
+        if {'\u4e00', '\u4e03', '\u4e5d', '\u5341', '\u5eff'}.issubset(s):
+            # lzh_TW
+            self.LC_alt_digits = lzh_TW_alt_digits
+            return
+
+        self.LC_alt_digits = None
+
+    def __calc_date_time(self):
+        # Set self.LC_date_time, self.LC_date, self.LC_time and
+        # self.LC_time_ampm by using time.strftime().
+
+        # Use (1999,3,17,22,44,55,2,76,0) for magic date because the amount of
+        # overloaded numbers is minimized.  The order in which searches for
+        # values within the format string is very important; it eliminates
+        # possible ambiguity for what something represents.
+        time_tuple = time.struct_time((1999,3,17,22,44,55,2,76,0))
+        time_tuple2 = time.struct_time((1999,1,3,1,1,1,6,3,0))
+        replacement_pairs = []
+
+        # Non-ASCII digits
+        if self.LC_alt_digits or self.LC_alt_digits is None:
+            for n, d in [(19, '%OC'), (99, '%Oy'), (22, '%OH'),
+                         (44, '%OM'), (55, '%OS'), (17, '%Od'),
+                         (3, '%Om'), (2, '%Ow'), (10, '%OI')]:
+                if self.LC_alt_digits is None:
+                    s = chr(0x660 + n // 10) + chr(0x660 + n % 10)
+                    replacement_pairs.append((s, d))
+                    if n < 10:
+                        replacement_pairs.append((s[1], d))
+                elif len(self.LC_alt_digits) > n:
+                    replacement_pairs.append((self.LC_alt_digits[n], d))
+                else:
+                    replacement_pairs.append((time.strftime(d, time_tuple), d))
+        replacement_pairs += [
+            ('1999', '%Y'), ('99', '%y'), ('22', '%H'),
+            ('44', '%M'), ('55', '%S'), ('76', '%j'),
+            ('17', '%d'), ('03', '%m'), ('3', '%m'),
+            # '3' needed for when no leading zero.
+            ('2', '%w'), ('10', '%I'),
+        ]
+
+        date_time = []
+        for directive in ('%c', '%x', '%X', '%r'):
+            current_format = time.strftime(directive, time_tuple).lower()
+            current_format = current_format.replace('%', '%%')
+            # The month and the day of the week formats are treated specially
+            # because of a possible ambiguity in some locales where the full
+            # and abbreviated names are equal or names of different types
+            # are equal. See doc of __find_month_format for more details.
+            lst, fmt = self.__find_weekday_format(directive)
+            if lst:
+                current_format = current_format.replace(lst[2], fmt, 1)
+            lst, fmt = self.__find_month_format(directive)
+            if lst:
+                current_format = current_format.replace(lst[3], fmt, 1)
+            if self.am_pm[1]:
+                # Must deal with possible lack of locale info
+                # manifesting itself as the empty string (e.g., Swedish's
+                # lack of AM/PM info) or a platform returning a tuple of empty
+                # strings (e.g., MacOS 9 having timezone as ('','')).
+                current_format = current_format.replace(self.am_pm[1], '%p')
+            for tz_values in self.timezone:
+                for tz in tz_values:
+                    if tz:
+                        current_format = current_format.replace(tz, "%Z")
+            # Transform all non-ASCII digits to digits in range U+0660 to U+0669.
+            if not current_format.isascii() and self.LC_alt_digits is None:
+                current_format = re_sub(r'\d(?<![0-9])',
+                                        lambda m: chr(0x0660 + int(m[0])),
+                                        current_format)
+            for old, new in replacement_pairs:
+                current_format = current_format.replace(old, new)
+            # If %W is used, then Sunday, 2005-01-03 will fall on week 0 since
+            # 2005-01-03 occurs before the first Monday of the year.  Otherwise
+            # %U is used.
+            if '00' in time.strftime(directive, time_tuple2):
+                U_W = '%W'
+            else:
+                U_W = '%U'
+            current_format = current_format.replace('11', U_W)
+            date_time.append(current_format)
+        self.LC_date_time = date_time[0]
+        self.LC_date = date_time[1]
+        self.LC_time = date_time[2]
+        self.LC_time_ampm = date_time[3]
+
+    def __find_month_format(self, directive):
+        """Find the month format appropriate for the current locale.
+
+        In some locales (for example French and Hebrew), the default month
+        used in __calc_date_time has the same name in full and abbreviated
+        form.  Also, the month name can by accident match other part of the
+        representation: the day of the week name (for example in Morisyen)
+        or the month number (for example in Japanese).  Thus, cycle months
+        of the year and find all positions that match the month name for
+        each month,  If no common positions are found, the representation
+        does not use the month name.
+        """
+        full_indices = abbr_indices = None
+        for m in range(1, 13):
+            time_tuple = time.struct_time((1999, m, 17, 22, 44, 55, 2, 76, 0))
+            datetime = time.strftime(directive, time_tuple).lower()
+            indices = set(_findall(datetime, self.f_month[m]))
+            if full_indices is None:
+                full_indices = indices
+            else:
+                full_indices &= indices
+            indices = set(_findall(datetime, self.a_month[m]))
+            if abbr_indices is None:
+                abbr_indices = set(indices)
+            else:
+                abbr_indices &= indices
+            if not full_indices and not abbr_indices:
+                return None, None
+        if full_indices:
+            return self.f_month, '%B'
+        if abbr_indices:
+            return self.a_month, '%b'
+        return None, None
+
+    def __find_weekday_format(self, directive):
+        """Find the day of the week format appropriate for the current locale.
+
+        Similar to __find_month_format().
+        """
+        full_indices = abbr_indices = None
+        for wd in range(7):
+            time_tuple = time.struct_time((1999, 3, 17, 22, 44, 55, wd, 76, 0))
+            datetime = time.strftime(directive, time_tuple).lower()
+            indices = set(_findall(datetime, self.f_weekday[wd]))
+            if full_indices is None:
+                full_indices = indices
+            else:
+                full_indices &= indices
+            if self.f_weekday[wd] != self.a_weekday[wd]:
+                indices = set(_findall(datetime, self.a_weekday[wd]))
+            if abbr_indices is None:
+                abbr_indices = set(indices)
+            else:
+                abbr_indices &= indices
+            if not full_indices and not abbr_indices:
+                return None, None
+        if full_indices:
+            return self.f_weekday, '%A'
+        if abbr_indices:
+            return self.a_weekday, '%a'
+        return None, None
+
+    def __calc_timezone(self):
+        # Set self.timezone by using time.tzname.
+        # Do not worry about possibility of time.tzname[0] == time.tzname[1]
+        # and time.daylight; handle that in strptime.
+        try:
+            time.tzset()
+        except AttributeError:
+            pass
+        self.tzname = time.tzname
+        self.daylight = time.daylight
+        no_saving = frozenset({"utc", "gmt", self.tzname[0].lower()})
+        if self.daylight:
+            has_saving = frozenset({self.tzname[1].lower()})
+        else:
+            has_saving = frozenset()
+        self.timezone = (no_saving, has_saving)
+
+
+class TimeRE(dict):
+    """Handle conversion from format directives to regexes."""
+
+    def __init__(self, locale_time=None):
+        """Create keys/values.
+
+        Order of execution is important for dependency reasons.
+
+        """
+        if locale_time:
+            self.locale_time = locale_time
+        else:
+            self.locale_time = LocaleTime()
+        base = super()
+        mapping = {
+            # The " [1-9]" part of the regex is to make %c from ANSI C work
+            'd': r"(?P<d>3[0-1]|[1-2]\d|0[1-9]|[1-9]| [1-9])",
+            'f': r"(?P<f>[0-9]{1,6})",
+            'H': r"(?P<H>2[0-3]|[0-1]\d|\d| \d)",
+            'k': r"(?P<H>2[0-3]|[0-1]\d|\d| \d)",
+            'I': r"(?P<I>1[0-2]|0[1-9]|[1-9]| [1-9])",
+            'l': r"(?P<I>1[0-2]|0[1-9]|[1-9]| [1-9])",
+            'G': r"(?P<G>\d\d\d\d)",
+            'j': r"(?P<j>36[0-6]|3[0-5]\d|[1-2]\d\d|0[1-9]\d|00[1-9]|[1-9]\d|0[1-9]|[1-9])",
+            'm': r"(?P<m>1[0-2]|0[1-9]|[1-9])",
+            'M': r"(?P<M>[0-5]\d|\d)",
+            'S': r"(?P<S>6[0-1]|[0-5]\d|\d)",
+            'U': r"(?P<U>5[0-3]|[0-4]\d|\d)",
+            'w': r"(?P<w>[0-6])",
+            'u': r"(?P<u>[1-7])",
+            'V': r"(?P<V>5[0-3]|0[1-9]|[1-4]\d|\d)",
+            # W is set below by using 'U'
+            'y': r"(?P<y>\d\d)",
+            'Y': r"(?P<Y>\d\d\d\d)",
+            'z': r"(?P<z>[+-]\d\d:?[0-5]\d(:?[0-5]\d(\.\d{1,6})?)?|(?-i:Z))",
+            'A': self.__seqToRE(self.locale_time.f_weekday, 'A'),
+            'a': self.__seqToRE(self.locale_time.a_weekday, 'a'),
+            'B': self.__seqToRE(_fixmonths(self.locale_time.f_month[1:]), 'B'),
+            'b': self.__seqToRE(_fixmonths(self.locale_time.a_month[1:]), 'b'),
+            'p': self.__seqToRE(self.locale_time.am_pm, 'p'),
+            'Z': self.__seqToRE((tz for tz_names in self.locale_time.timezone
+                                        for tz in tz_names),
+                                'Z'),
+            '%': '%'}
+        if self.locale_time.LC_alt_digits is None:
+            for d in 'dmyCHIMS':
+                mapping['O' + d] = r'(?P<%s>\d\d|\d| \d)' % d
+            mapping['Ow'] = r'(?P<w>\d)'
+        else:
+            mapping.update({
+                'Od': self.__seqToRE(self.locale_time.LC_alt_digits[1:32], 'd',
+                                     '3[0-1]|[1-2][0-9]|0[1-9]|[1-9]'),
+                'Om': self.__seqToRE(self.locale_time.LC_alt_digits[1:13], 'm',
+                                     '1[0-2]|0[1-9]|[1-9]'),
+                'Ow': self.__seqToRE(self.locale_time.LC_alt_digits[:7], 'w',
+                                     '[0-6]'),
+                'Oy': self.__seqToRE(self.locale_time.LC_alt_digits, 'y',
+                                     '[0-9][0-9]'),
+                'OC': self.__seqToRE(self.locale_time.LC_alt_digits, 'C',
+                                     '[0-9][0-9]'),
+                'OH': self.__seqToRE(self.locale_time.LC_alt_digits[:24], 'H',
+                                     '2[0-3]|[0-1][0-9]|[0-9]'),
+                'OI': self.__seqToRE(self.locale_time.LC_alt_digits[1:13], 'I',
+                                     '1[0-2]|0[1-9]|[1-9]'),
+                'OM': self.__seqToRE(self.locale_time.LC_alt_digits[:60], 'M',
+                                     '[0-5][0-9]|[0-9]'),
+                'OS': self.__seqToRE(self.locale_time.LC_alt_digits[:62], 'S',
+                                     '6[0-1]|[0-5][0-9]|[0-9]'),
+            })
+        mapping.update({
+            'e': mapping['d'],
+            'Oe': mapping['Od'],
+            'P': mapping['p'],
+            'Op': mapping['p'],
+            'W': mapping['U'].replace('U', 'W'),
+        })
+        mapping['W'] = mapping['U'].replace('U', 'W')
+
+        base.__init__(mapping)
+        base.__setitem__('T', self.pattern('%H:%M:%S'))
+        base.__setitem__('R', self.pattern('%H:%M'))
+        base.__setitem__('r', self.pattern(self.locale_time.LC_time_ampm))
+        base.__setitem__('X', self.pattern(self.locale_time.LC_time))
+        base.__setitem__('x', self.pattern(self.locale_time.LC_date))
+        base.__setitem__('c', self.pattern(self.locale_time.LC_date_time))
+
+    def __seqToRE(self, to_convert, directive, altregex=None):
+        """Convert a list to a regex string for matching a directive.
+
+        Want possible matching values to be from longest to shortest.  This
+        prevents the possibility of a match occurring for a value that also
+        a substring of a larger value that should have matched (e.g., 'abc'
+        matching when 'abcdef' should have been the match).
+
+        """
+        to_convert = sorted(to_convert, key=len, reverse=True)
+        for value in to_convert:
+            if value != '':
+                break
+        else:
+            return ''
+        regex = '|'.join(re_escape(stuff) for stuff in to_convert)
+        if altregex is not None:
+            regex += '|' + altregex
+        return '(?P<%s>%s)' % (directive, regex)
+
+    def pattern(self, format):
+        """Return regex pattern for the format string.
+
+        Need to make sure that any characters that might be interpreted as
+        regex syntax are escaped.
+
+        """
+        # The sub() call escapes all characters that might be misconstrued
+        # as regex syntax.  Cannot use re.escape since we have to deal with
+        # format directives (%m, etc.).
+        format = re_sub(r"([\\.^$*+?\(\){}\[\]|])", r"\\\1", format)
+        format = re_sub(r'\s+', r'\\s+', format)
+        format = re_sub(r"'", "['\u02bc]", format)  # needed for br_FR
+        year_in_format = False
+        day_of_month_in_format = False
+        def repl(m):
+            format_char = m[1]
+            match format_char:
+                case 'Y' | 'y' | 'G':
+                    nonlocal year_in_format
+                    year_in_format = True
+                case 'd':
+                    nonlocal day_of_month_in_format
+                    day_of_month_in_format = True
+            return self[format_char]
+        format = re_sub(r'%[-_0^#]*[0-9]*([OE]?\\?.?)', repl, format)
+        if day_of_month_in_format and not year_in_format:
+            import warnings
+            warnings.warn("""\
+Parsing dates involving a day of month without a year specified is ambiguious
+and fails to parse leap day. The default behavior will change in Python 3.15
+to either always raise an exception or to use a different default year (TBD).
+To avoid trouble, add a specific year to the input & format.
+See https://github.com/python/cpython/issues/70647.""",
+                          DeprecationWarning,
+                          skip_file_prefixes=(os.path.dirname(__file__),))
+        return format
+
+    def compile(self, format):
+        """Return a compiled re object for the format string."""
+        return re_compile(self.pattern(format), IGNORECASE)
+
+_cache_lock = _thread_allocate_lock()
+# DO NOT modify _TimeRE_cache or _regex_cache without acquiring the cache lock
+# first!
+_TimeRE_cache = TimeRE()
+_CACHE_MAX_SIZE = 5 # Max number of regexes stored in _regex_cache
+_regex_cache = {}
+
+def _calc_julian_from_U_or_W(year, week_of_year, day_of_week, week_starts_Mon):
+    """Calculate the Julian day based on the year, week of the year, and day of
+    the week, with week_start_day representing whether the week of the year
+    assumes the week starts on Sunday or Monday (6 or 0)."""
+    first_weekday = datetime_date(year, 1, 1).weekday()
+    # If we are dealing with the %U directive (week starts on Sunday), it's
+    # easier to just shift the view to Sunday being the first day of the
+    # week.
+    if not week_starts_Mon:
+        first_weekday = (first_weekday + 1) % 7
+        day_of_week = (day_of_week + 1) % 7
+    # Need to watch out for a week 0 (when the first day of the year is not
+    # the same as that specified by %U or %W).
+    week_0_length = (7 - first_weekday) % 7
+    if week_of_year == 0:
+        return 1 + day_of_week - first_weekday
+    else:
+        days_to_week = week_0_length + (7 * (week_of_year - 1))
+        return 1 + days_to_week + day_of_week
+
+
+def _strptime(data_string, format="%a %b %d %H:%M:%S %Y"):
+    """Return a 2-tuple consisting of a time struct and an int containing
+    the number of microseconds based on the input string and the
+    format string."""
+
+    for index, arg in enumerate([data_string, format]):
+        if not isinstance(arg, str):
+            msg = "strptime() argument {} must be str, not {}"
+            raise TypeError(msg.format(index, type(arg)))
+
+    global _TimeRE_cache, _regex_cache
+    with _cache_lock:
+        locale_time = _TimeRE_cache.locale_time
+        if (_getlang() != locale_time.lang or
+            time.tzname != locale_time.tzname or
+            time.daylight != locale_time.daylight):
+            _TimeRE_cache = TimeRE()
+            _regex_cache.clear()
+            locale_time = _TimeRE_cache.locale_time
+        if len(_regex_cache) > _CACHE_MAX_SIZE:
+            _regex_cache.clear()
+        format_regex = _regex_cache.get(format)
+        if not format_regex:
+            try:
+                format_regex = _TimeRE_cache.compile(format)
+            # KeyError raised when a bad format is found; can be specified as
+            # \\, in which case it was a stray % but with a space after it
+            except KeyError as err:
+                bad_directive = err.args[0]
+                del err
+                bad_directive = bad_directive.replace('\\s', '')
+                if not bad_directive:
+                    raise ValueError("stray %% in format '%s'" % format) from None
+                bad_directive = bad_directive.replace('\\', '', 1)
+                raise ValueError("'%s' is a bad directive in format '%s'" %
+                                    (bad_directive, format)) from None
+            _regex_cache[format] = format_regex
+    found = format_regex.match(data_string)
+    if not found:
+        raise ValueError("time data %r does not match format %r" %
+                         (data_string, format))
+    if len(data_string) != found.end():
+        raise ValueError("unconverted data remains: %s" %
+                          data_string[found.end():])
+
+    iso_year = year = None
+    month = day = 1
+    hour = minute = second = fraction = 0
+    tz = -1
+    gmtoff = None
+    gmtoff_fraction = 0
+    iso_week = week_of_year = None
+    week_of_year_start = None
+    # weekday and julian defaulted to None so as to signal need to calculate
+    # values
+    weekday = julian = None
+    found_dict = found.groupdict()
+    if locale_time.LC_alt_digits:
+        def parse_int(s):
+            try:
+                return locale_time.LC_alt_digits.index(s)
+            except ValueError:
+                return int(s)
+    else:
+        parse_int = int
+
+    for group_key in found_dict.keys():
+        # Directives not explicitly handled below:
+        #   c, x, X
+        #      handled by making out of other directives
+        #   U, W
+        #      worthless without day of the week
+        if group_key == 'y':
+            year = parse_int(found_dict['y'])
+            if 'C' in found_dict:
+                century = parse_int(found_dict['C'])
+                year += century * 100
+            else:
+                # Open Group specification for strptime() states that a %y
+                #value in the range of [00, 68] is in the century 2000, while
+                #[69,99] is in the century 1900
+                if year <= 68:
+                    year += 2000
+                else:
+                    year += 1900
+        elif group_key == 'Y':
+            year = int(found_dict['Y'])
+        elif group_key == 'G':
+            iso_year = int(found_dict['G'])
+        elif group_key == 'm':
+            month = parse_int(found_dict['m'])
+        elif group_key == 'B':
+            month = locale_time.f_month.index(found_dict['B'].lower())
+        elif group_key == 'b':
+            month = locale_time.a_month.index(found_dict['b'].lower())
+        elif group_key == 'd':
+            day = parse_int(found_dict['d'])
+        elif group_key == 'H':
+            hour = parse_int(found_dict['H'])
+        elif group_key == 'I':
+            hour = parse_int(found_dict['I'])
+            ampm = found_dict.get('p', '').lower()
+            # If there was no AM/PM indicator, we'll treat this like AM
+            if ampm in ('', locale_time.am_pm[0]):
+                # We're in AM so the hour is correct unless we're
+                # looking at 12 midnight.
+                # 12 midnight == 12 AM == hour 0
+                if hour == 12:
+                    hour = 0
+            elif ampm == locale_time.am_pm[1]:
+                # We're in PM so we need to add 12 to the hour unless
+                # we're looking at 12 noon.
+                # 12 noon == 12 PM == hour 12
+                if hour != 12:
+                    hour += 12
+        elif group_key == 'M':
+            minute = parse_int(found_dict['M'])
+        elif group_key == 'S':
+            second = parse_int(found_dict['S'])
+        elif group_key == 'f':
+            s = found_dict['f']
+            # Pad to always return microseconds.
+            s += "0" * (6 - len(s))
+            fraction = int(s)
+        elif group_key == 'A':
+            weekday = locale_time.f_weekday.index(found_dict['A'].lower())
+        elif group_key == 'a':
+            weekday = locale_time.a_weekday.index(found_dict['a'].lower())
+        elif group_key == 'w':
+            weekday = int(found_dict['w'])
+            if weekday == 0:
+                weekday = 6
+            else:
+                weekday -= 1
+        elif group_key == 'u':
+            weekday = int(found_dict['u'])
+            weekday -= 1
+        elif group_key == 'j':
+            julian = int(found_dict['j'])
+        elif group_key in ('U', 'W'):
+            week_of_year = int(found_dict[group_key])
+            if group_key == 'U':
+                # U starts week on Sunday.
+                week_of_year_start = 6
+            else:
+                # W starts week on Monday.
+                week_of_year_start = 0
+        elif group_key == 'V':
+            iso_week = int(found_dict['V'])
+        elif group_key == 'z':
+            z = found_dict['z']
+            if z == 'Z':
+                gmtoff = 0
+            else:
+                if z[3] == ':':
+                    z = z[:3] + z[4:]
+                    if len(z) > 5:
+                        if z[5] != ':':
+                            msg = f"Inconsistent use of : in {found_dict['z']}"
+                            raise ValueError(msg)
+                        z = z[:5] + z[6:]
+                hours = int(z[1:3])
+                minutes = int(z[3:5])
+                seconds = int(z[5:7] or 0)
+                gmtoff = (hours * 60 * 60) + (minutes * 60) + seconds
+                gmtoff_remainder = z[8:]
+                # Pad to always return microseconds.
+                gmtoff_remainder_padding = "0" * (6 - len(gmtoff_remainder))
+                gmtoff_fraction = int(gmtoff_remainder + gmtoff_remainder_padding)
+                if z.startswith("-"):
+                    gmtoff = -gmtoff
+                    gmtoff_fraction = -gmtoff_fraction
+        elif group_key == 'Z':
+            # Since -1 is default value only need to worry about setting tz if
+            # it can be something other than -1.
+            found_zone = found_dict['Z'].lower()
+            for value, tz_values in enumerate(locale_time.timezone):
+                if found_zone in tz_values:
+                    # Deal with bad locale setup where timezone names are the
+                    # same and yet time.daylight is true; too ambiguous to
+                    # be able to tell what timezone has daylight savings
+                    if (time.tzname[0] == time.tzname[1] and
+                       time.daylight and found_zone not in ("utc", "gmt")):
+                        break
+                    else:
+                        tz = value
+                        break
+
+    # Deal with the cases where ambiguities arise
+    # don't assume default values for ISO week/year
+    if iso_year is not None:
+        if julian is not None:
+            raise ValueError("Day of the year directive '%j' is not "
+                             "compatible with ISO year directive '%G'. "
+                             "Use '%Y' instead.")
+        elif iso_week is None or weekday is None:
+            raise ValueError("ISO year directive '%G' must be used with "
+                             "the ISO week directive '%V' and a weekday "
+                             "directive ('%A', '%a', '%w', or '%u').")
+    elif iso_week is not None:
+        if year is None or weekday is None:
+            raise ValueError("ISO week directive '%V' must be used with "
+                             "the ISO year directive '%G' and a weekday "
+                             "directive ('%A', '%a', '%w', or '%u').")
+        else:
+            raise ValueError("ISO week directive '%V' is incompatible with "
+                             "the year directive '%Y'. Use the ISO year '%G' "
+                             "instead.")
+
+    leap_year_fix = False
+    if year is None:
+        if month == 2 and day == 29:
+            year = 1904  # 1904 is first leap year of 20th century
+            leap_year_fix = True
+        else:
+            year = 1900
+
+    # If we know the week of the year and what day of that week, we can figure
+    # out the Julian day of the year.
+    if julian is None and weekday is not None:
+        if week_of_year is not None:
+            week_starts_Mon = True if week_of_year_start == 0 else False
+            julian = _calc_julian_from_U_or_W(year, week_of_year, weekday,
+                                                week_starts_Mon)
+        elif iso_year is not None and iso_week is not None:
+            datetime_result = datetime_date.fromisocalendar(iso_year, iso_week, weekday + 1)
+            year = datetime_result.year
+            month = datetime_result.month
+            day = datetime_result.day
+        if julian is not None and julian <= 0:
+            year -= 1
+            yday = 366 if calendar.isleap(year) else 365
+            julian += yday
+
+    if julian is None:
+        # Cannot pre-calculate datetime_date() since can change in Julian
+        # calculation and thus could have different value for the day of
+        # the week calculation.
+        # Need to add 1 to result since first day of the year is 1, not 0.
+        julian = datetime_date(year, month, day).toordinal() - \
+                  datetime_date(year, 1, 1).toordinal() + 1
+    else:  # Assume that if they bothered to include Julian day (or if it was
+           # calculated above with year/week/weekday) it will be accurate.
+        datetime_result = datetime_date.fromordinal(
+                            (julian - 1) +
+                            datetime_date(year, 1, 1).toordinal())
+        year = datetime_result.year
+        month = datetime_result.month
+        day = datetime_result.day
+    if weekday is None:
+        weekday = datetime_date(year, month, day).weekday()
+    # Add timezone info
+    tzname = found_dict.get("Z")
+
+    if leap_year_fix:
+        # the caller didn't supply a year but asked for Feb 29th. We couldn't
+        # use the default of 1900 for computations. We set it back to ensure
+        # that February 29th is smaller than March 1st.
+        year = 1900
+
+    return (year, month, day,
+            hour, minute, second,
+            weekday, julian, tz, tzname, gmtoff), fraction, gmtoff_fraction
+
+def _strptime_time(data_string, format="%a %b %d %H:%M:%S %Y"):
+    """Return a time struct based on the input string and the
+    format string."""
+    tt = _strptime(data_string, format)[0]
+    return time.struct_time(tt[:time._STRUCT_TM_ITEMS])
+
+def _strptime_datetime(cls, data_string, format="%a %b %d %H:%M:%S %Y"):
+    """Return a class cls instance based on the input string and the
+    format string."""
+    tt, fraction, gmtoff_fraction = _strptime(data_string, format)
+    tzname, gmtoff = tt[-2:]
+    args = tt[:6] + (fraction,)
+    if gmtoff is not None:
+        tzdelta = datetime_timedelta(seconds=gmtoff, microseconds=gmtoff_fraction)
+        if tzname:
+            tz = datetime_timezone(tzdelta, tzname)
+        else:
+            tz = datetime_timezone(tzdelta)
+        args += (tz,)
+
+    return cls(*args)
--- a/Lib/_threading_local.py
+++ b/Lib/_threading_local.py
@@ -4,133 +4,6 @@
 class.  Depending on the version of Python you're using, there may be a
 faster one available.  You should always import the `local` class from
 `threading`.)
-
-Thread-local objects support the management of thread-local data.
-If you have data that you want to be local to a thread, simply create
-a thread-local object and use its attributes:
-
-  >>> mydata = local()
-  >>> mydata.number = 42
-  >>> mydata.number
-  42
-
-You can also access the local-object's dictionary:
-
-  >>> mydata.__dict__
-  {'number': 42}
-  >>> mydata.__dict__.setdefault('widgets', [])
-  []
-  >>> mydata.widgets
-  []
-
-What's important about thread-local objects is that their data are
-local to a thread. If we access the data in a different thread:
-
-  >>> log = []
-  >>> def f():
-  ...     items = sorted(mydata.__dict__.items())
-  ...     log.append(items)
-  ...     mydata.number = 11
-  ...     log.append(mydata.number)
-
-  >>> import threading
-  >>> thread = threading.Thread(target=f)
-  >>> thread.start()
-  >>> thread.join()
-  >>> log
-  [[], 11]
-
-we get different data.  Furthermore, changes made in the other thread
-don't affect data seen in this thread:
-
-  >>> mydata.number
-  42
-
-Of course, values you get from a local object, including a __dict__
-attribute, are for whatever thread was current at the time the
-attribute was read.  For that reason, you generally don't want to save
-these values across threads, as they apply only to the thread they
-came from.
-
-You can create custom local objects by subclassing the local class:
-
-  >>> class MyLocal(local):
-  ...     number = 2
-  ...     initialized = False
-  ...     def __init__(self, **kw):
-  ...         if self.initialized:
-  ...             raise SystemError('__init__ called too many times')
-  ...         self.initialized = True
-  ...         self.__dict__.update(kw)
-  ...     def squared(self):
-  ...         return self.number ** 2
-
-This can be useful to support default values, methods and
-initialization.  Note that if you define an __init__ method, it will be
-called each time the local object is used in a separate thread.  This
-is necessary to initialize each thread's dictionary.
-
-Now if we create a local object:
-
-  >>> mydata = MyLocal(color='red')
-
-Now we have a default number:
-
-  >>> mydata.number
-  2
-
-an initial color:
-
-  >>> mydata.color
-  'red'
-  >>> del mydata.color
-
-And a method that operates on the data:
-
-  >>> mydata.squared()
-  4
-
-As before, we can access the data in a separate thread:
-
-  >>> log = []
-  >>> thread = threading.Thread(target=f)
-  >>> thread.start()
-  >>> thread.join()
-  >>> log
-  [[('color', 'red'), ('initialized', True)], 11]
-
-without affecting this thread's data:
-
-  >>> mydata.number
-  2
-  >>> mydata.color
-  Traceback (most recent call last):
-  ...
-  AttributeError: 'MyLocal' object has no attribute 'color'
-
-Note that subclasses can define slots, but they are not thread
-local. They are shared across threads:
-
-  >>> class MyLocal(local):
-  ...     __slots__ = 'number'
-
-  >>> mydata = MyLocal()
-  >>> mydata.number = 42
-  >>> mydata.color = 'red'
-
-So, the separate thread:
-
-  >>> thread = threading.Thread(target=f)
-  >>> thread.start()
-  >>> thread.join()
-
-affects what we see:
-
-  >>> # TODO: RUSTPYTHON, __slots__
-  >>> mydata.number #doctest: +SKIP
-  11
-
->>> del mydata
 """

 from weakref import ref
@@ -194,7 +67,6 @@ class _localimpl:

@contextmanager
 def _patch(self):
-    old = object.__getattribute__(self, '__dict__')
    impl = object.__getattribute__(self, '_local__impl')
    try:
        dct = impl.get_dict()
@@ -205,13 +77,12 @@ def _patch(self):
    with impl.locallock:
        object.__setattr__(self, '__dict__', dct)
        yield
-        object.__setattr__(self, '__dict__', old)


 class local:
    __slots__ = '_local__impl', '__dict__'

-    def __new__(cls, *args, **kw):
+    def __new__(cls, /, *args, **kw):
        if (args or kw) and (cls.__init__ is object.__init__):
            raise TypeError("Initialization arguments are not supported")
        self = object.__new__(cls)
--- a/Lib/_weakrefset.py
+++ b/Lib/_weakrefset.py
@@ -80,8 +80,7 @@ class WeakSet:
        return wr in self.data

    def __reduce__(self):
-        return (self.__class__, (list(self),),
-                getattr(self, '__dict__', None))
+        return self.__class__, (list(self),), self.__getstate__()

    def add(self, item):
        if self._pending_removals:
--- a/Lib/abc.py
+++ b/Lib/abc.py
@@ -18,7 +18,7 @@ def abstractmethod(funcobj):

        class C(metaclass=ABCMeta):
            @abstractmethod
-            def my_abstract_method(self, ...):
+            def my_abstract_method(self, arg1, arg2, argN):
                ...
    """
    funcobj.__isabstractmethod__ = True
@@ -85,10 +85,6 @@ try:
    from _abc import (get_cache_token, _abc_init, _abc_register,
                      _abc_instancecheck, _abc_subclasscheck, _get_dump,
                      _reset_registry, _reset_caches)
-# TODO: RUSTPYTHON missing _abc module implementation.
-except ModuleNotFoundError:
-    from _py_abc import ABCMeta, get_cache_token
-    ABCMeta.__module__ = 'abc'
 except ImportError:
    from _py_abc import ABCMeta, get_cache_token
    ABCMeta.__module__ = 'abc'
--- a/Lib/aifc.py
+++ b/Lib/aifc.py
@@ -1,984 +0,0 @@
-"""Stuff to parse AIFF-C and AIFF files.
-
-Unless explicitly stated otherwise, the description below is true
-both for AIFF-C files and AIFF files.
-
-An AIFF-C file has the following structure.
-
-  +-----------------+
-  | FORM            |
-  +-----------------+
-  | <size>          |
-  +----+------------+
-  |    | AIFC       |
-  |    +------------+
-  |    | <chunks>   |
-  |    |    .       |
-  |    |    .       |
-  |    |    .       |
-  +----+------------+
-
-An AIFF file has the string "AIFF" instead of "AIFC".
-
-A chunk consists of an identifier (4 bytes) followed by a size (4 bytes,
-big endian order), followed by the data.  The size field does not include
-the size of the 8 byte header.
-
-The following chunk types are recognized.
-
-  FVER
-      <version number of AIFF-C defining document> (AIFF-C only).
-  MARK
-      <# of markers> (2 bytes)
-      list of markers:
-          <marker ID> (2 bytes, must be > 0)
-          <position> (4 bytes)
-          <marker name> ("pstring")
-  COMM
-      <# of channels> (2 bytes)
-      <# of sound frames> (4 bytes)
-      <size of the samples> (2 bytes)
-      <sampling frequency> (10 bytes, IEEE 80-bit extended
-          floating point)
-      in AIFF-C files only:
-      <compression type> (4 bytes)
-      <human-readable version of compression type> ("pstring")
-  SSND
-      <offset> (4 bytes, not used by this program)
-      <blocksize> (4 bytes, not used by this program)
-      <sound data>
-
-A pstring consists of 1 byte length, a string of characters, and 0 or 1
-byte pad to make the total length even.
-
-Usage.
-
-Reading AIFF files:
-  f = aifc.open(file, 'r')
-where file is either the name of a file or an open file pointer.
-The open file pointer must have methods read(), seek(), and close().
-In some types of audio files, if the setpos() method is not used,
-the seek() method is not necessary.
-
-This returns an instance of a class with the following public methods:
-  getnchannels()  -- returns number of audio channels (1 for
-             mono, 2 for stereo)
-  getsampwidth()  -- returns sample width in bytes
-  getframerate()  -- returns sampling frequency
-  getnframes()    -- returns number of audio frames
-  getcomptype()   -- returns compression type ('NONE' for AIFF files)
-  getcompname()   -- returns human-readable version of
-             compression type ('not compressed' for AIFF files)
-  getparams() -- returns a namedtuple consisting of all of the
-             above in the above order
-  getmarkers()    -- get the list of marks in the audio file or None
-             if there are no marks
-  getmark(id) -- get mark with the specified id (raises an error
-             if the mark does not exist)
-  readframes(n)   -- returns at most n frames of audio
-  rewind()    -- rewind to the beginning of the audio stream
-  setpos(pos) -- seek to the specified position
-  tell()      -- return the current position
-  close()     -- close the instance (make it unusable)
-The position returned by tell(), the position given to setpos() and
-the position of marks are all compatible and have nothing to do with
-the actual position in the file.
-The close() method is called automatically when the class instance
-is destroyed.
-
-Writing AIFF files:
-  f = aifc.open(file, 'w')
-where file is either the name of a file or an open file pointer.
-The open file pointer must have methods write(), tell(), seek(), and
-close().
-
-This returns an instance of a class with the following public methods:
-  aiff()      -- create an AIFF file (AIFF-C default)
-  aifc()      -- create an AIFF-C file
-  setnchannels(n) -- set the number of channels
-  setsampwidth(n) -- set the sample width
-  setframerate(n) -- set the frame rate
-  setnframes(n)   -- set the number of frames
-  setcomptype(type, name)
-          -- set the compression type and the
-             human-readable compression type
-  setparams(tuple)
-          -- set all parameters at once
-  setmark(id, pos, name)
-          -- add specified mark to the list of marks
-  tell()      -- return current position in output file (useful
-             in combination with setmark())
-  writeframesraw(data)
-          -- write audio frames without pathing up the
-             file header
-  writeframes(data)
-          -- write audio frames and patch up the file header
-  close()     -- patch up the file header and close the
-             output file
-You should set the parameters before the first writeframesraw or
-writeframes.  The total number of frames does not need to be set,
-but when it is set to the correct value, the header does not have to
-be patched up.
-It is best to first set all parameters, perhaps possibly the
-compression type, and then write audio frames using writeframesraw.
-When all frames have been written, either call writeframes(b'') or
-close() to patch up the sizes in the header.
-Marks can be added anytime.  If there are any marks, you must call
-close() after all frames have been written.
-The close() method is called automatically when the class instance
-is destroyed.
-
-When a file is opened with the extension '.aiff', an AIFF file is
-written, otherwise an AIFF-C file is written.  This default can be
-changed by calling aiff() or aifc() before the first writeframes or
-writeframesraw.
-"""
-
-import struct
-import builtins
-import warnings
-
-__all__ = ["Error", "open"]
-
-
-warnings._deprecated(__name__, remove=(3, 13))
-
-
-class Error(Exception):
-    pass
-
-_AIFC_version = 0xA2805140     # Version 1 of AIFF-C
-
-def _read_long(file):
-    try:
-        return struct.unpack('>l', file.read(4))[0]
-    except struct.error:
-        raise EOFError from None
-
-def _read_ulong(file):
-    try:
-        return struct.unpack('>L', file.read(4))[0]
-    except struct.error:
-        raise EOFError from None
-
-def _read_short(file):
-    try:
-        return struct.unpack('>h', file.read(2))[0]
-    except struct.error:
-        raise EOFError from None
-
-def _read_ushort(file):
-    try:
-        return struct.unpack('>H', file.read(2))[0]
-    except struct.error:
-        raise EOFError from None
-
-def _read_string(file):
-    length = ord(file.read(1))
-    if length == 0:
-        data = b''
-    else:
-        data = file.read(length)
-    if length & 1 == 0:
-        dummy = file.read(1)
-    return data
-
-_HUGE_VAL = 1.79769313486231e+308 # See <limits.h>
-
-def _read_float(f): # 10 bytes
-    expon = _read_short(f) # 2 bytes
-    sign = 1
-    if expon < 0:
-        sign = -1
-        expon = expon + 0x8000
-    himant = _read_ulong(f) # 4 bytes
-    lomant = _read_ulong(f) # 4 bytes
-    if expon == himant == lomant == 0:
-        f = 0.0
-    elif expon == 0x7FFF:
-        f = _HUGE_VAL
-    else:
-        expon = expon - 16383
-        f = (himant * 0x100000000 + lomant) * pow(2.0, expon - 63)
-    return sign * f
-
-def _write_short(f, x):
-    f.write(struct.pack('>h', x))
-
-def _write_ushort(f, x):
-    f.write(struct.pack('>H', x))
-
-def _write_long(f, x):
-    f.write(struct.pack('>l', x))
-
-def _write_ulong(f, x):
-    f.write(struct.pack('>L', x))
-
-def _write_string(f, s):
-    if len(s) > 255:
-        raise ValueError("string exceeds maximum pstring length")
-    f.write(struct.pack('B', len(s)))
-    f.write(s)
-    if len(s) & 1 == 0:
-        f.write(b'\x00')
-
-def _write_float(f, x):
-    import math
-    if x < 0:
-        sign = 0x8000
-        x = x * -1
-    else:
-        sign = 0
-    if x == 0:
-        expon = 0
-        himant = 0
-        lomant = 0
-    else:
-        fmant, expon = math.frexp(x)
-        if expon > 16384 or fmant >= 1 or fmant != fmant: # Infinity or NaN
-            expon = sign|0x7FFF
-            himant = 0
-            lomant = 0
-        else:                   # Finite
-            expon = expon + 16382
-            if expon < 0:           # denormalized
-                fmant = math.ldexp(fmant, expon)
-                expon = 0
-            expon = expon | sign
-            fmant = math.ldexp(fmant, 32)
-            fsmant = math.floor(fmant)
-            himant = int(fsmant)
-            fmant = math.ldexp(fmant - fsmant, 32)
-            fsmant = math.floor(fmant)
-            lomant = int(fsmant)
-    _write_ushort(f, expon)
-    _write_ulong(f, himant)
-    _write_ulong(f, lomant)
-
-with warnings.catch_warnings():
-    warnings.simplefilter("ignore", DeprecationWarning)
-    from chunk import Chunk
-from collections import namedtuple
-
-_aifc_params = namedtuple('_aifc_params',
-                          'nchannels sampwidth framerate nframes comptype compname')
-
-_aifc_params.nchannels.__doc__ = 'Number of audio channels (1 for mono, 2 for stereo)'
-_aifc_params.sampwidth.__doc__ = 'Sample width in bytes'
-_aifc_params.framerate.__doc__ = 'Sampling frequency'
-_aifc_params.nframes.__doc__ = 'Number of audio frames'
-_aifc_params.comptype.__doc__ = 'Compression type ("NONE" for AIFF files)'
-_aifc_params.compname.__doc__ = ("""\
-A human-readable version of the compression type
-('not compressed' for AIFF files)""")
-
-
-class Aifc_read:
-    # Variables used in this class:
-    #
-    # These variables are available to the user though appropriate
-    # methods of this class:
-    # _file -- the open file with methods read(), close(), and seek()
-    #       set through the __init__() method
-    # _nchannels -- the number of audio channels
-    #       available through the getnchannels() method
-    # _nframes -- the number of audio frames
-    #       available through the getnframes() method
-    # _sampwidth -- the number of bytes per audio sample
-    #       available through the getsampwidth() method
-    # _framerate -- the sampling frequency
-    #       available through the getframerate() method
-    # _comptype -- the AIFF-C compression type ('NONE' if AIFF)
-    #       available through the getcomptype() method
-    # _compname -- the human-readable AIFF-C compression type
-    #       available through the getcomptype() method
-    # _markers -- the marks in the audio file
-    #       available through the getmarkers() and getmark()
-    #       methods
-    # _soundpos -- the position in the audio stream
-    #       available through the tell() method, set through the
-    #       setpos() method
-    #
-    # These variables are used internally only:
-    # _version -- the AIFF-C version number
-    # _decomp -- the decompressor from builtin module cl
-    # _comm_chunk_read -- 1 iff the COMM chunk has been read
-    # _aifc -- 1 iff reading an AIFF-C file
-    # _ssnd_seek_needed -- 1 iff positioned correctly in audio
-    #       file for readframes()
-    # _ssnd_chunk -- instantiation of a chunk class for the SSND chunk
-    # _framesize -- size of one frame in the file
-
-    _file = None  # Set here since __del__ checks it
-
-    def initfp(self, file):
-        self._version = 0
-        self._convert = None
-        self._markers = []
-        self._soundpos = 0
-        self._file = file
-        chunk = Chunk(file)
-        if chunk.getname() != b'FORM':
-            raise Error('file does not start with FORM id')
-        formdata = chunk.read(4)
-        if formdata == b'AIFF':
-            self._aifc = 0
-        elif formdata == b'AIFC':
-            self._aifc = 1
-        else:
-            raise Error('not an AIFF or AIFF-C file')
-        self._comm_chunk_read = 0
-        self._ssnd_chunk = None
-        while 1:
-            self._ssnd_seek_needed = 1
-            try:
-                chunk = Chunk(self._file)
-            except EOFError:
-                break
-            chunkname = chunk.getname()
-            if chunkname == b'COMM':
-                self._read_comm_chunk(chunk)
-                self._comm_chunk_read = 1
-            elif chunkname == b'SSND':
-                self._ssnd_chunk = chunk
-                dummy = chunk.read(8)
-                self._ssnd_seek_needed = 0
-            elif chunkname == b'FVER':
-                self._version = _read_ulong(chunk)
-            elif chunkname == b'MARK':
-                self._readmark(chunk)
-            chunk.skip()
-        if not self._comm_chunk_read or not self._ssnd_chunk:
-            raise Error('COMM chunk and/or SSND chunk missing')
-
-    def __init__(self, f):
-        if isinstance(f, str):
-            file_object = builtins.open(f, 'rb')
-            try:
-                self.initfp(file_object)
-            except:
-                file_object.close()
-                raise
-        else:
-            # assume it is an open file object already
-            self.initfp(f)
-
-    def __enter__(self):
-        return self
-
-    def __exit__(self, *args):
-        self.close()
-
-    #
-    # User visible methods.
-    #
-    def getfp(self):
-        return self._file
-
-    def rewind(self):
-        self._ssnd_seek_needed = 1
-        self._soundpos = 0
-
-    def close(self):
-        file = self._file
-        if file is not None:
-            self._file = None
-            file.close()
-
-    def tell(self):
-        return self._soundpos
-
-    def getnchannels(self):
-        return self._nchannels
-
-    def getnframes(self):
-        return self._nframes
-
-    def getsampwidth(self):
-        return self._sampwidth
-
-    def getframerate(self):
-        return self._framerate
-
-    def getcomptype(self):
-        return self._comptype
-
-    def getcompname(self):
-        return self._compname
-
-##  def getversion(self):
-##      return self._version
-
-    def getparams(self):
-        return _aifc_params(self.getnchannels(), self.getsampwidth(),
-                            self.getframerate(), self.getnframes(),
-                            self.getcomptype(), self.getcompname())
-
-    def getmarkers(self):
-        if len(self._markers) == 0:
-            return None
-        return self._markers
-
-    def getmark(self, id):
-        for marker in self._markers:
-            if id == marker[0]:
-                return marker
-        raise Error('marker {0!r} does not exist'.format(id))
-
-    def setpos(self, pos):
-        if pos < 0 or pos > self._nframes:
-            raise Error('position not in range')
-        self._soundpos = pos
-        self._ssnd_seek_needed = 1
-
-    def readframes(self, nframes):
-        if self._ssnd_seek_needed:
-            self._ssnd_chunk.seek(0)
-            dummy = self._ssnd_chunk.read(8)
-            pos = self._soundpos * self._framesize
-            if pos:
-                self._ssnd_chunk.seek(pos + 8)
-            self._ssnd_seek_needed = 0
-        if nframes == 0:
-            return b''
-        data = self._ssnd_chunk.read(nframes * self._framesize)
-        if self._convert and data:
-            data = self._convert(data)
-        self._soundpos = self._soundpos + len(data) // (self._nchannels
-                                                        * self._sampwidth)
-        return data
-
-    #
-    # Internal methods.
-    #
-
-    def _alaw2lin(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        return audioop.alaw2lin(data, 2)
-
-    def _ulaw2lin(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        return audioop.ulaw2lin(data, 2)
-
-    def _adpcm2lin(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        if not hasattr(self, '_adpcmstate'):
-            # first time
-            self._adpcmstate = None
-        data, self._adpcmstate = audioop.adpcm2lin(data, 2, self._adpcmstate)
-        return data
-
-    def _sowt2lin(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        return audioop.byteswap(data, 2)
-
-    def _read_comm_chunk(self, chunk):
-        self._nchannels = _read_short(chunk)
-        self._nframes = _read_long(chunk)
-        self._sampwidth = (_read_short(chunk) + 7) // 8
-        self._framerate = int(_read_float(chunk))
-        if self._sampwidth <= 0:
-            raise Error('bad sample width')
-        if self._nchannels <= 0:
-            raise Error('bad # of channels')
-        self._framesize = self._nchannels * self._sampwidth
-        if self._aifc:
-            #DEBUG: SGI's soundeditor produces a bad size :-(
-            kludge = 0
-            if chunk.chunksize == 18:
-                kludge = 1
-                warnings.warn('Warning: bad COMM chunk size')
-                chunk.chunksize = 23
-            #DEBUG end
-            self._comptype = chunk.read(4)
-            #DEBUG start
-            if kludge:
-                length = ord(chunk.file.read(1))
-                if length & 1 == 0:
-                    length = length + 1
-                chunk.chunksize = chunk.chunksize + length
-                chunk.file.seek(-1, 1)
-            #DEBUG end
-            self._compname = _read_string(chunk)
-            if self._comptype != b'NONE':
-                if self._comptype == b'G722':
-                    self._convert = self._adpcm2lin
-                elif self._comptype in (b'ulaw', b'ULAW'):
-                    self._convert = self._ulaw2lin
-                elif self._comptype in (b'alaw', b'ALAW'):
-                    self._convert = self._alaw2lin
-                elif self._comptype in (b'sowt', b'SOWT'):
-                    self._convert = self._sowt2lin
-                else:
-                    raise Error('unsupported compression type')
-                self._sampwidth = 2
-        else:
-            self._comptype = b'NONE'
-            self._compname = b'not compressed'
-
-    def _readmark(self, chunk):
-        nmarkers = _read_short(chunk)
-        # Some files appear to contain invalid counts.
-        # Cope with this by testing for EOF.
-        try:
-            for i in range(nmarkers):
-                id = _read_short(chunk)
-                pos = _read_long(chunk)
-                name = _read_string(chunk)
-                if pos or name:
-                    # some files appear to have
-                    # dummy markers consisting of
-                    # a position 0 and name ''
-                    self._markers.append((id, pos, name))
-        except EOFError:
-            w = ('Warning: MARK chunk contains only %s marker%s instead of %s' %
-                 (len(self._markers), '' if len(self._markers) == 1 else 's',
-                  nmarkers))
-            warnings.warn(w)
-
-class Aifc_write:
-    # Variables used in this class:
-    #
-    # These variables are user settable through appropriate methods
-    # of this class:
-    # _file -- the open file with methods write(), close(), tell(), seek()
-    #       set through the __init__() method
-    # _comptype -- the AIFF-C compression type ('NONE' in AIFF)
-    #       set through the setcomptype() or setparams() method
-    # _compname -- the human-readable AIFF-C compression type
-    #       set through the setcomptype() or setparams() method
-    # _nchannels -- the number of audio channels
-    #       set through the setnchannels() or setparams() method
-    # _sampwidth -- the number of bytes per audio sample
-    #       set through the setsampwidth() or setparams() method
-    # _framerate -- the sampling frequency
-    #       set through the setframerate() or setparams() method
-    # _nframes -- the number of audio frames written to the header
-    #       set through the setnframes() or setparams() method
-    # _aifc -- whether we're writing an AIFF-C file or an AIFF file
-    #       set through the aifc() method, reset through the
-    #       aiff() method
-    #
-    # These variables are used internally only:
-    # _version -- the AIFF-C version number
-    # _comp -- the compressor from builtin module cl
-    # _nframeswritten -- the number of audio frames actually written
-    # _datalength -- the size of the audio samples written to the header
-    # _datawritten -- the size of the audio samples actually written
-
-    _file = None  # Set here since __del__ checks it
-
-    def __init__(self, f):
-        if isinstance(f, str):
-            file_object = builtins.open(f, 'wb')
-            try:
-                self.initfp(file_object)
-            except:
-                file_object.close()
-                raise
-
-            # treat .aiff file extensions as non-compressed audio
-            if f.endswith('.aiff'):
-                self._aifc = 0
-        else:
-            # assume it is an open file object already
-            self.initfp(f)
-
-    def initfp(self, file):
-        self._file = file
-        self._version = _AIFC_version
-        self._comptype = b'NONE'
-        self._compname = b'not compressed'
-        self._convert = None
-        self._nchannels = 0
-        self._sampwidth = 0
-        self._framerate = 0
-        self._nframes = 0
-        self._nframeswritten = 0
-        self._datawritten = 0
-        self._datalength = 0
-        self._markers = []
-        self._marklength = 0
-        self._aifc = 1      # AIFF-C is default
-
-    def __del__(self):
-        self.close()
-
-    def __enter__(self):
-        return self
-
-    def __exit__(self, *args):
-        self.close()
-
-    #
-    # User visible methods.
-    #
-    def aiff(self):
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        self._aifc = 0
-
-    def aifc(self):
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        self._aifc = 1
-
-    def setnchannels(self, nchannels):
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        if nchannels < 1:
-            raise Error('bad # of channels')
-        self._nchannels = nchannels
-
-    def getnchannels(self):
-        if not self._nchannels:
-            raise Error('number of channels not set')
-        return self._nchannels
-
-    def setsampwidth(self, sampwidth):
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        if sampwidth < 1 or sampwidth > 4:
-            raise Error('bad sample width')
-        self._sampwidth = sampwidth
-
-    def getsampwidth(self):
-        if not self._sampwidth:
-            raise Error('sample width not set')
-        return self._sampwidth
-
-    def setframerate(self, framerate):
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        if framerate <= 0:
-            raise Error('bad frame rate')
-        self._framerate = framerate
-
-    def getframerate(self):
-        if not self._framerate:
-            raise Error('frame rate not set')
-        return self._framerate
-
-    def setnframes(self, nframes):
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        self._nframes = nframes
-
-    def getnframes(self):
-        return self._nframeswritten
-
-    def setcomptype(self, comptype, compname):
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        if comptype not in (b'NONE', b'ulaw', b'ULAW',
-                            b'alaw', b'ALAW', b'G722', b'sowt', b'SOWT'):
-            raise Error('unsupported compression type')
-        self._comptype = comptype
-        self._compname = compname
-
-    def getcomptype(self):
-        return self._comptype
-
-    def getcompname(self):
-        return self._compname
-
-##  def setversion(self, version):
-##      if self._nframeswritten:
-##          raise Error, 'cannot change parameters after starting to write'
-##      self._version = version
-
-    def setparams(self, params):
-        nchannels, sampwidth, framerate, nframes, comptype, compname = params
-        if self._nframeswritten:
-            raise Error('cannot change parameters after starting to write')
-        if comptype not in (b'NONE', b'ulaw', b'ULAW',
-                            b'alaw', b'ALAW', b'G722', b'sowt', b'SOWT'):
-            raise Error('unsupported compression type')
-        self.setnchannels(nchannels)
-        self.setsampwidth(sampwidth)
-        self.setframerate(framerate)
-        self.setnframes(nframes)
-        self.setcomptype(comptype, compname)
-
-    def getparams(self):
-        if not self._nchannels or not self._sampwidth or not self._framerate:
-            raise Error('not all parameters set')
-        return _aifc_params(self._nchannels, self._sampwidth, self._framerate,
-                            self._nframes, self._comptype, self._compname)
-
-    def setmark(self, id, pos, name):
-        if id <= 0:
-            raise Error('marker ID must be > 0')
-        if pos < 0:
-            raise Error('marker position must be >= 0')
-        if not isinstance(name, bytes):
-            raise Error('marker name must be bytes')
-        for i in range(len(self._markers)):
-            if id == self._markers[i][0]:
-                self._markers[i] = id, pos, name
-                return
-        self._markers.append((id, pos, name))
-
-    def getmark(self, id):
-        for marker in self._markers:
-            if id == marker[0]:
-                return marker
-        raise Error('marker {0!r} does not exist'.format(id))
-
-    def getmarkers(self):
-        if len(self._markers) == 0:
-            return None
-        return self._markers
-
-    def tell(self):
-        return self._nframeswritten
-
-    def writeframesraw(self, data):
-        if not isinstance(data, (bytes, bytearray)):
-            data = memoryview(data).cast('B')
-        self._ensure_header_written(len(data))
-        nframes = len(data) // (self._sampwidth * self._nchannels)
-        if self._convert:
-            data = self._convert(data)
-        self._file.write(data)
-        self._nframeswritten = self._nframeswritten + nframes
-        self._datawritten = self._datawritten + len(data)
-
-    def writeframes(self, data):
-        self.writeframesraw(data)
-        if self._nframeswritten != self._nframes or \
-              self._datalength != self._datawritten:
-            self._patchheader()
-
-    def close(self):
-        if self._file is None:
-            return
-        try:
-            self._ensure_header_written(0)
-            if self._datawritten & 1:
-                # quick pad to even size
-                self._file.write(b'\x00')
-                self._datawritten = self._datawritten + 1
-            self._writemarkers()
-            if self._nframeswritten != self._nframes or \
-                  self._datalength != self._datawritten or \
-                  self._marklength:
-                self._patchheader()
-        finally:
-            # Prevent ref cycles
-            self._convert = None
-            f = self._file
-            self._file = None
-            f.close()
-
-    #
-    # Internal methods.
-    #
-
-    def _lin2alaw(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        return audioop.lin2alaw(data, 2)
-
-    def _lin2ulaw(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        return audioop.lin2ulaw(data, 2)
-
-    def _lin2adpcm(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        if not hasattr(self, '_adpcmstate'):
-            self._adpcmstate = None
-        data, self._adpcmstate = audioop.lin2adpcm(data, 2, self._adpcmstate)
-        return data
-
-    def _lin2sowt(self, data):
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', category=DeprecationWarning)
-            import audioop
-        return audioop.byteswap(data, 2)
-
-    def _ensure_header_written(self, datasize):
-        if not self._nframeswritten:
-            if self._comptype in (b'ULAW', b'ulaw',
-                b'ALAW', b'alaw', b'G722',
-                b'sowt', b'SOWT'):
-                if not self._sampwidth:
-                    self._sampwidth = 2
-                if self._sampwidth != 2:
-                    raise Error('sample width must be 2 when compressing '
-                                'with ulaw/ULAW, alaw/ALAW, sowt/SOWT '
-                                'or G7.22 (ADPCM)')
-            if not self._nchannels:
-                raise Error('# channels not specified')
-            if not self._sampwidth:
-                raise Error('sample width not specified')
-            if not self._framerate:
-                raise Error('sampling rate not specified')
-            self._write_header(datasize)
-
-    def _init_compression(self):
-        if self._comptype == b'G722':
-            self._convert = self._lin2adpcm
-        elif self._comptype in (b'ulaw', b'ULAW'):
-            self._convert = self._lin2ulaw
-        elif self._comptype in (b'alaw', b'ALAW'):
-            self._convert = self._lin2alaw
-        elif self._comptype in (b'sowt', b'SOWT'):
-            self._convert = self._lin2sowt
-
-    def _write_header(self, initlength):
-        if self._aifc and self._comptype != b'NONE':
-            self._init_compression()
-        self._file.write(b'FORM')
-        if not self._nframes:
-            self._nframes = initlength // (self._nchannels * self._sampwidth)
-        self._datalength = self._nframes * self._nchannels * self._sampwidth
-        if self._datalength & 1:
-            self._datalength = self._datalength + 1
-        if self._aifc:
-            if self._comptype in (b'ulaw', b'ULAW', b'alaw', b'ALAW'):
-                self._datalength = self._datalength // 2
-                if self._datalength & 1:
-                    self._datalength = self._datalength + 1
-            elif self._comptype == b'G722':
-                self._datalength = (self._datalength + 3) // 4
-                if self._datalength & 1:
-                    self._datalength = self._datalength + 1
-        try:
-            self._form_length_pos = self._file.tell()
-        except (AttributeError, OSError):
-            self._form_length_pos = None
-        commlength = self._write_form_length(self._datalength)
-        if self._aifc:
-            self._file.write(b'AIFC')
-            self._file.write(b'FVER')
-            _write_ulong(self._file, 4)
-            _write_ulong(self._file, self._version)
-        else:
-            self._file.write(b'AIFF')
-        self._file.write(b'COMM')
-        _write_ulong(self._file, commlength)
-        _write_short(self._file, self._nchannels)
-        if self._form_length_pos is not None:
-            self._nframes_pos = self._file.tell()
-        _write_ulong(self._file, self._nframes)
-        if self._comptype in (b'ULAW', b'ulaw', b'ALAW', b'alaw', b'G722'):
-            _write_short(self._file, 8)
-        else:
-            _write_short(self._file, self._sampwidth * 8)
-        _write_float(self._file, self._framerate)
-        if self._aifc:
-            self._file.write(self._comptype)
-            _write_string(self._file, self._compname)
-        self._file.write(b'SSND')
-        if self._form_length_pos is not None:
-            self._ssnd_length_pos = self._file.tell()
-        _write_ulong(self._file, self._datalength + 8)
-        _write_ulong(self._file, 0)
-        _write_ulong(self._file, 0)
-
-    def _write_form_length(self, datalength):
-        if self._aifc:
-            commlength = 18 + 5 + len(self._compname)
-            if commlength & 1:
-                commlength = commlength + 1
-            verslength = 12
-        else:
-            commlength = 18
-            verslength = 0
-        _write_ulong(self._file, 4 + verslength + self._marklength + \
-                     8 + commlength + 16 + datalength)
-        return commlength
-
-    def _patchheader(self):
-        curpos = self._file.tell()
-        if self._datawritten & 1:
-            datalength = self._datawritten + 1
-            self._file.write(b'\x00')
-        else:
-            datalength = self._datawritten
-        if datalength == self._datalength and \
-              self._nframes == self._nframeswritten and \
-              self._marklength == 0:
-            self._file.seek(curpos, 0)
-            return
-        self._file.seek(self._form_length_pos, 0)
-        dummy = self._write_form_length(datalength)
-        self._file.seek(self._nframes_pos, 0)
-        _write_ulong(self._file, self._nframeswritten)
-        self._file.seek(self._ssnd_length_pos, 0)
-        _write_ulong(self._file, datalength + 8)
-        self._file.seek(curpos, 0)
-        self._nframes = self._nframeswritten
-        self._datalength = datalength
-
-    def _writemarkers(self):
-        if len(self._markers) == 0:
-            return
-        self._file.write(b'MARK')
-        length = 2
-        for marker in self._markers:
-            id, pos, name = marker
-            length = length + len(name) + 1 + 6
-            if len(name) & 1 == 0:
-                length = length + 1
-        _write_ulong(self._file, length)
-        self._marklength = length + 8
-        _write_short(self._file, len(self._markers))
-        for marker in self._markers:
-            id, pos, name = marker
-            _write_short(self._file, id)
-            _write_ulong(self._file, pos)
-            _write_string(self._file, name)
-
-def open(f, mode=None):
-    if mode is None:
-        if hasattr(f, 'mode'):
-            mode = f.mode
-        else:
-            mode = 'rb'
-    if mode in ('r', 'rb'):
-        return Aifc_read(f)
-    elif mode in ('w', 'wb'):
-        return Aifc_write(f)
-    else:
-        raise Error("mode must be 'r', 'rb', 'w', or 'wb'")
-
-
-if __name__ == '__main__':
-    import sys
-    if not sys.argv[1:]:
-        sys.argv.append('/usr/demos/data/audio/bach.aiff')
-    fn = sys.argv[1]
-    with open(fn, 'r') as f:
-        print("Reading", fn)
-        print("nchannels =", f.getnchannels())
-        print("nframes   =", f.getnframes())
-        print("sampwidth =", f.getsampwidth())
-        print("framerate =", f.getframerate())
-        print("comptype  =", f.getcomptype())
-        print("compname  =", f.getcompname())
-        if sys.argv[2:]:
-            gn = sys.argv[2]
-            print("Writing", gn)
-            with open(gn, 'w') as g:
-                g.setparams(f.getparams())
-                while 1:
-                    data = f.readframes(1024)
-                    if not data:
-                        break
-                    g.writeframes(data)
-            print("Done.")
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -1,54 +1,54 @@
 """
-    ast
-    ~~~
+The `ast` module helps Python applications to process trees of the Python
+abstract syntax grammar.  The abstract syntax itself might change with
+each Python release; this module helps to find out programmatically what
+the current grammar looks like and allows modifications of it.

-    The `ast` module helps Python applications to process trees of the Python
-    abstract syntax grammar.  The abstract syntax itself might change with
-    each Python release; this module helps to find out programmatically what
-    the current grammar looks like and allows modifications of it.
+An abstract syntax tree can be generated by passing `ast.PyCF_ONLY_AST` as
+a flag to the `compile()` builtin function or by using the `parse()`
+function from this module.  The result will be a tree of objects whose
+classes all inherit from `ast.AST`.

-    An abstract syntax tree can be generated by passing `ast.PyCF_ONLY_AST` as
-    a flag to the `compile()` builtin function or by using the `parse()`
-    function from this module.  The result will be a tree of objects whose
-    classes all inherit from `ast.AST`.
+A modified abstract syntax tree can be compiled into a Python code object
+using the built-in `compile()` function.

-    A modified abstract syntax tree can be compiled into a Python code object
-    using the built-in `compile()` function.
+Additionally various helper functions are provided that make working with
+the trees simpler.  The main intention of the helper functions and this
+module in general is to provide an easy to use interface for libraries
+that work tightly with the python syntax (template engines for example).

-    Additionally various helper functions are provided that make working with
-    the trees simpler.  The main intention of the helper functions and this
-    module in general is to provide an easy to use interface for libraries
-    that work tightly with the python syntax (template engines for example).
-
-
-    :copyright: Copyright 2008 by Armin Ronacher.
-    :license: Python License.
+:copyright: Copyright 2008 by Armin Ronacher.
+:license: Python License.
 """
 import sys
+import re
 from _ast import *
 from contextlib import contextmanager, nullcontext
-from enum import IntEnum, auto
+from enum import IntEnum, auto, _simple_enum


 def parse(source, filename='<unknown>', mode='exec', *,
-          type_comments=False, feature_version=None):
+          type_comments=False, feature_version=None, optimize=-1):
    """
    Parse the source into an AST node.
    Equivalent to compile(source, filename, mode, PyCF_ONLY_AST).
    Pass type_comments=True to get back type comments where the syntax allows.
    """
    flags = PyCF_ONLY_AST
+    if optimize > 0:
+        flags |= PyCF_OPTIMIZED_AST
    if type_comments:
        flags |= PyCF_TYPE_COMMENTS
-    if isinstance(feature_version, tuple):
-        major, minor = feature_version  # Should be a 2-tuple.
-        assert major == 3
-        feature_version = minor
-    elif feature_version is None:
+    if feature_version is None:
        feature_version = -1
+    elif isinstance(feature_version, tuple):
+        major, minor = feature_version  # Should be a 2-tuple.
+        if major != 3:
+            raise ValueError(f"Unsupported major version: {major}")
+        feature_version = minor
    # Else it should be an int giving the minor version for 3.x.
    return compile(source, filename, mode, flags,
-                   _feature_version=feature_version)
+                   _feature_version=feature_version, optimize=optimize)


 def literal_eval(node_or_string):
@@ -110,7 +110,11 @@ def literal_eval(node_or_string):
    return _convert(node_or_string)


-def dump(node, annotate_fields=True, include_attributes=False, *, indent=None):
+def dump(
+    node, annotate_fields=True, include_attributes=False,
+    *,
+    indent=None, show_empty=False,
+):
    """
    Return a formatted dump of the tree in node.  This is mainly useful for
    debugging purposes.  If annotate_fields is true (by default),
@@ -121,6 +125,8 @@ def dump(node, annotate_fields=True, include_attributes=False, *, indent=None):
    include_attributes can be set to true.  If indent is a non-negative
    integer or string, then the tree will be pretty-printed with that indent
    level. None (the default) selects the single line representation.
+    If show_empty is False, then empty lists and fields that are None
+    will be omitted from the output for better readability.
    """
    def _format(node, level=0):
        if indent is not None:
@@ -133,6 +139,7 @@ def dump(node, annotate_fields=True, include_attributes=False, *, indent=None):
        if isinstance(node, AST):
            cls = type(node)
            args = []
+            args_buffer = []
            allsimple = True
            keywords = annotate_fields
            for name in node._fields:
@@ -144,6 +151,16 @@ def dump(node, annotate_fields=True, include_attributes=False, *, indent=None):
                if value is None and getattr(cls, name, ...) is None:
                    keywords = True
                    continue
+                if not show_empty:
+                    if value == []:
+                        field_type = cls._field_types.get(name, object)
+                        if getattr(field_type, '__origin__', ...) is list:
+                            if not keywords:
+                                args_buffer.append(repr(value))
+                            continue
+                    if not keywords:
+                        args.extend(args_buffer)
+                        args_buffer = []
                value, simple = _format(value, level)
                allsimple = allsimple and simple
                if keywords:
@@ -292,9 +309,7 @@ def get_docstring(node, clean=True):
    if not(node.body and isinstance(node.body[0], Expr)):
        return None
    node = node.body[0].value
-    if isinstance(node, Str):
-        text = node.s
-    elif isinstance(node, Constant) and isinstance(node.value, str):
+    if isinstance(node, Constant) and isinstance(node.value, str):
        text = node.value
    else:
        return None
@@ -304,28 +319,17 @@ def get_docstring(node, clean=True):
    return text


-def _splitlines_no_ff(source):
+_line_pattern = re.compile(r"(.*?(?:\r\n|\n|\r|$))")
+def _splitlines_no_ff(source, maxlines=None):
    """Split a string into lines ignoring form feed and other chars.

    This mimics how the Python parser splits source code.
    """
-    idx = 0
    lines = []
-    next_line = ''
-    while idx < len(source):
-        c = source[idx]
-        next_line += c
-        idx += 1
-        # Keep \r\n together
-        if c == '\r' and idx < len(source) and source[idx] == '\n':
-            next_line += '\n'
-            idx += 1
-        if c in '\r\n':
-            lines.append(next_line)
-            next_line = ''
-
-    if next_line:
-        lines.append(next_line)
+    for lineno, match in enumerate(_line_pattern.finditer(source), 1):
+        if maxlines is not None and lineno > maxlines:
+            break
+        lines.append(match[0])
    return lines


@@ -359,7 +363,7 @@ def get_source_segment(source, node, *, padded=False):
    except AttributeError:
        return None

-    lines = _splitlines_no_ff(source)
+    lines = _splitlines_no_ff(source, maxlines=end_lineno+1)
    if end_lineno == lineno:
        return lines[lineno].encode()[col_offset:end_col_offset].decode()

@@ -508,20 +512,52 @@ class NodeTransformer(NodeVisitor):
        return node


+_DEPRECATED_VALUE_ALIAS_MESSAGE = (
+    "{name} is deprecated and will be removed in Python {remove}; use value instead"
+)
+_DEPRECATED_CLASS_MESSAGE = (
+    "{name} is deprecated and will be removed in Python {remove}; "
+    "use ast.Constant instead"
+)
+
+
 # If the ast module is loaded more than once, only add deprecated methods once
 if not hasattr(Constant, 'n'):
    # The following code is for backward compatibility.
    # It will be removed in future.

-    def _getter(self):
+    def _n_getter(self):
        """Deprecated. Use value instead."""
+        import warnings
+        warnings._deprecated(
+            "Attribute n", message=_DEPRECATED_VALUE_ALIAS_MESSAGE, remove=(3, 14)
+        )
        return self.value

-    def _setter(self, value):
+    def _n_setter(self, value):
+        import warnings
+        warnings._deprecated(
+            "Attribute n", message=_DEPRECATED_VALUE_ALIAS_MESSAGE, remove=(3, 14)
+        )
        self.value = value

-    Constant.n = property(_getter, _setter)
-    Constant.s = property(_getter, _setter)
+    def _s_getter(self):
+        """Deprecated. Use value instead."""
+        import warnings
+        warnings._deprecated(
+            "Attribute s", message=_DEPRECATED_VALUE_ALIAS_MESSAGE, remove=(3, 14)
+        )
+        return self.value
+
+    def _s_setter(self, value):
+        import warnings
+        warnings._deprecated(
+            "Attribute s", message=_DEPRECATED_VALUE_ALIAS_MESSAGE, remove=(3, 14)
+        )
+        self.value = value
+
+    Constant.n = property(_n_getter, _n_setter)
+    Constant.s = property(_s_getter, _s_setter)

 class _ABC(type):

@@ -529,6 +565,13 @@ class _ABC(type):
        cls.__doc__ = """Deprecated AST node class. Use ast.Constant instead"""

    def __instancecheck__(cls, inst):
+        if cls in _const_types:
+            import warnings
+            warnings._deprecated(
+                f"ast.{cls.__qualname__}",
+                message=_DEPRECATED_CLASS_MESSAGE,
+                remove=(3, 14)
+            )
        if not isinstance(inst, Constant):
            return False
        if cls in _const_types:
@@ -552,6 +595,10 @@ def _new(cls, *args, **kwargs):
        if pos < len(args):
            raise TypeError(f"{cls.__name__} got multiple values for argument {key!r}")
    if cls in _const_types:
+        import warnings
+        warnings._deprecated(
+            f"ast.{cls.__qualname__}", message=_DEPRECATED_CLASS_MESSAGE, remove=(3, 14)
+        )
        return Constant(*args, **kwargs)
    return Constant.__new__(cls, *args, **kwargs)

@@ -574,10 +621,19 @@ class Ellipsis(Constant, metaclass=_ABC):
    _fields = ()

    def __new__(cls, *args, **kwargs):
-        if cls is Ellipsis:
+        if cls is _ast_Ellipsis:
+            import warnings
+            warnings._deprecated(
+                "ast.Ellipsis", message=_DEPRECATED_CLASS_MESSAGE, remove=(3, 14)
+            )
            return Constant(..., *args, **kwargs)
        return Constant.__new__(cls, *args, **kwargs)

+# Keep another reference to Ellipsis in the global namespace
+# so it can be referenced in Ellipsis.__new__
+# (The original "Ellipsis" name is removed from the global namespace later on)
+_ast_Ellipsis = Ellipsis
+
 _const_types = {
    Num: (int, float, complex),
    Str: (str,),
@@ -644,10 +700,12 @@ class Param(expr_context):
 # We unparse those infinities to INFSTR.
 _INFSTR = "1e" + repr(sys.float_info.max_10_exp + 1)

-class _Precedence(IntEnum):
+@_simple_enum(IntEnum)
+class _Precedence:
    """Precedence table that originated from python grammar."""

-    TUPLE = auto()
+    NAMED_EXPR = auto()      # <target> := <expr1>
+    TUPLE = auto()           # <expr1>, <expr2>
    YIELD = auto()           # 'yield', 'yield from'
    TEST = auto()            # 'if'-'else', 'lambda'
    OR = auto()              # 'or'
@@ -683,13 +741,12 @@ class _Unparser(NodeVisitor):
    output source code for the abstract syntax; original formatting
    is disregarded."""

-    def __init__(self, *, _avoid_backslashes=False):
+    def __init__(self):
        self._source = []
-        self._buffer = []
        self._precedences = {}
        self._type_ignores = {}
        self._indent = 0
-        self._avoid_backslashes = _avoid_backslashes
+        self._in_try_star = False

    def interleave(self, inter, f, seq):
        """Call f on each item in seq, calling inter() in between."""
@@ -724,18 +781,19 @@ class _Unparser(NodeVisitor):
        self.maybe_newline()
        self.write("    " * self._indent + text)

-    def write(self, text):
-        """Append a piece of text"""
-        self._source.append(text)
+    def write(self, *text):
+        """Add new source parts"""
+        self._source.extend(text)

-    def buffer_writer(self, text):
-        self._buffer.append(text)
+    @contextmanager
+    def buffered(self, buffer = None):
+        if buffer is None:
+            buffer = []

-    @property
-    def buffer(self):
-        value = "".join(self._buffer)
-        self._buffer.clear()
-        return value
+        original_source = self._source
+        self._source = buffer
+        yield buffer
+        self._source = original_source

    @contextmanager
    def block(self, *, extra = None):
@@ -845,7 +903,7 @@ class _Unparser(NodeVisitor):
        self.traverse(node.value)

    def visit_NamedExpr(self, node):
-        with self.require_parens(_Precedence.TUPLE, node):
+        with self.require_parens(_Precedence.NAMED_EXPR, node):
            self.set_precedence(_Precedence.ATOM, node.target, node.value)
            self.traverse(node.target)
            self.write(" := ")
@@ -866,6 +924,7 @@ class _Unparser(NodeVisitor):
    def visit_Assign(self, node):
        self.fill()
        for target in node.targets:
+            self.set_precedence(_Precedence.TUPLE, target)
            self.traverse(target)
            self.write(" = ")
        self.traverse(node.value)
@@ -958,7 +1017,7 @@ class _Unparser(NodeVisitor):
            self.write(" from ")
            self.traverse(node.cause)

-    def visit_Try(self, node):
+    def do_visit_try(self, node):
        self.fill("try")
        with self.block():
            self.traverse(node.body)
@@ -973,8 +1032,24 @@ class _Unparser(NodeVisitor):
            with self.block():
                self.traverse(node.finalbody)

+    def visit_Try(self, node):
+        prev_in_try_star = self._in_try_star
+        try:
+            self._in_try_star = False
+            self.do_visit_try(node)
+        finally:
+            self._in_try_star = prev_in_try_star
+
+    def visit_TryStar(self, node):
+        prev_in_try_star = self._in_try_star
+        try:
+            self._in_try_star = True
+            self.do_visit_try(node)
+        finally:
+            self._in_try_star = prev_in_try_star
+
    def visit_ExceptHandler(self, node):
-        self.fill("except")
+        self.fill("except*" if self._in_try_star else "except")
        if node.type:
            self.write(" ")
            self.traverse(node.type)
@@ -990,6 +1065,8 @@ class _Unparser(NodeVisitor):
            self.fill("@")
            self.traverse(deco)
        self.fill("class " + node.name)
+        if hasattr(node, "type_params"):
+            self._type_params_helper(node.type_params)
        with self.delimit_if("(", ")", condition = node.bases or node.keywords):
            comma = False
            for e in node.bases:
@@ -1021,6 +1098,8 @@ class _Unparser(NodeVisitor):
            self.traverse(deco)
        def_str = fill_suffix + " " + node.name
        self.fill(def_str)
+        if hasattr(node, "type_params"):
+            self._type_params_helper(node.type_params)
        with self.delimit("(", ")"):
            self.traverse(node.args)
        if node.returns:
@@ -1029,6 +1108,39 @@ class _Unparser(NodeVisitor):
        with self.block(extra=self.get_type_comment(node)):
            self._write_docstring_and_traverse_body(node)

+    def _type_params_helper(self, type_params):
+        if type_params is not None and len(type_params) > 0:
+            with self.delimit("[", "]"):
+                self.interleave(lambda: self.write(", "), self.traverse, type_params)
+
+    def visit_TypeVar(self, node):
+        self.write(node.name)
+        if node.bound:
+            self.write(": ")
+            self.traverse(node.bound)
+        if node.default_value:
+            self.write(" = ")
+            self.traverse(node.default_value)
+
+    def visit_TypeVarTuple(self, node):
+        self.write("*" + node.name)
+        if node.default_value:
+            self.write(" = ")
+            self.traverse(node.default_value)
+
+    def visit_ParamSpec(self, node):
+        self.write("**" + node.name)
+        if node.default_value:
+            self.write(" = ")
+            self.traverse(node.default_value)
+
+    def visit_TypeAlias(self, node):
+        self.fill("type ")
+        self.traverse(node.name)
+        self._type_params_helper(node.type_params)
+        self.write(" = ")
+        self.traverse(node.value)
+
    def visit_For(self, node):
        self._for_helper("for ", node)

@@ -1037,6 +1149,7 @@ class _Unparser(NodeVisitor):

    def _for_helper(self, fill, node):
        self.fill(fill)
+        self.set_precedence(_Precedence.TUPLE, node.target)
        self.traverse(node.target)
        self.write(" in ")
        self.traverse(node.iter)
@@ -1133,71 +1246,92 @@ class _Unparser(NodeVisitor):

    def visit_JoinedStr(self, node):
        self.write("f")
-        if self._avoid_backslashes:
-            self._fstring_JoinedStr(node, self.buffer_writer)
-            self._write_str_avoiding_backslashes(self.buffer)
-            return

-        # If we don't need to avoid backslashes globally (i.e., we only need
-        # to avoid them inside FormattedValues), it's cosmetically preferred
-        # to use escaped whitespace. That is, it's preferred to use backslashes
-        # for cases like: f"{x}\n". To accomplish this, we keep track of what
-        # in our buffer corresponds to FormattedValues and what corresponds to
-        # Constant parts of the f-string, and allow escapes accordingly.
-        buffer = []
+        fstring_parts = []
        for value in node.values:
-            meth = getattr(self, "_fstring_" + type(value).__name__)
-            meth(value, self.buffer_writer)
-            buffer.append((self.buffer, isinstance(value, Constant)))
-        new_buffer = []
-        quote_types = _ALL_QUOTES
-        for value, is_constant in buffer:
-            # Repeatedly narrow down the list of possible quote_types
-            value, quote_types = self._str_literal_helper(
-                value, quote_types=quote_types,
-                escape_special_whitespace=is_constant
+            with self.buffered() as buffer:
+                self._write_fstring_inner(value)
+            fstring_parts.append(
+                ("".join(buffer), isinstance(value, Constant))
            )
-            new_buffer.append(value)
-        value = "".join(new_buffer)
+
+        new_fstring_parts = []
+        quote_types = list(_ALL_QUOTES)
+        fallback_to_repr = False
+        for value, is_constant in fstring_parts:
+            if is_constant:
+                value, new_quote_types = self._str_literal_helper(
+                    value,
+                    quote_types=quote_types,
+                    escape_special_whitespace=True,
+                )
+                if set(new_quote_types).isdisjoint(quote_types):
+                    fallback_to_repr = True
+                    break
+                quote_types = new_quote_types
+            else:
+                if "\n" in value:
+                    quote_types = [q for q in quote_types if q in _MULTI_QUOTES]
+                    assert quote_types
+
+                new_quote_types = [q for q in quote_types if q not in value]
+                if new_quote_types:
+                    quote_types = new_quote_types
+            new_fstring_parts.append(value)
+
+        if fallback_to_repr:
+            # If we weren't able to find a quote type that works for all parts
+            # of the JoinedStr, fallback to using repr and triple single quotes.
+            quote_types = ["'''"]
+            new_fstring_parts.clear()
+            for value, is_constant in fstring_parts:
+                if is_constant:
+                    value = repr('"' + value)  # force repr to use single quotes
+                    expected_prefix = "'\""
+                    assert value.startswith(expected_prefix), repr(value)
+                    value = value[len(expected_prefix):-1]
+                new_fstring_parts.append(value)
+
+        value = "".join(new_fstring_parts)
        quote_type = quote_types[0]
        self.write(f"{quote_type}{value}{quote_type}")

+    def _write_fstring_inner(self, node, is_format_spec=False):
+        if isinstance(node, JoinedStr):
+            # for both the f-string itself, and format_spec
+            for value in node.values:
+                self._write_fstring_inner(value, is_format_spec=is_format_spec)
+        elif isinstance(node, Constant) and isinstance(node.value, str):
+            value = node.value.replace("{", "{{").replace("}", "}}")
+
+            if is_format_spec:
+                value = value.replace("\\", "\\\\")
+                value = value.replace("'", "\\'")
+                value = value.replace('"', '\\"')
+                value = value.replace("\n", "\\n")
+            self.write(value)
+        elif isinstance(node, FormattedValue):
+            self.visit_FormattedValue(node)
+        else:
+            raise ValueError(f"Unexpected node inside JoinedStr, {node!r}")
+
    def visit_FormattedValue(self, node):
-        self.write("f")
-        self._fstring_FormattedValue(node, self.buffer_writer)
-        self._write_str_avoiding_backslashes(self.buffer)
+        def unparse_inner(inner):
+            unparser = type(self)()
+            unparser.set_precedence(_Precedence.TEST.next(), inner)
+            return unparser.visit(inner)

-    def _fstring_JoinedStr(self, node, write):
-        for value in node.values:
-            meth = getattr(self, "_fstring_" + type(value).__name__)
-            meth(value, write)
-
-    def _fstring_Constant(self, node, write):
-        if not isinstance(node.value, str):
-            raise ValueError("Constants inside JoinedStr should be a string.")
-        value = node.value.replace("{", "{{").replace("}", "}}")
-        write(value)
-
-    def _fstring_FormattedValue(self, node, write):
-        write("{")
-        unparser = type(self)(_avoid_backslashes=True)
-        unparser.set_precedence(_Precedence.TEST.next(), node.value)
-        expr = unparser.visit(node.value)
-        if expr.startswith("{"):
-            write(" ")  # Separate pair of opening brackets as "{ {"
-        if "\\" in expr:
-            raise ValueError("Unable to avoid backslash in f-string expression part")
-        write(expr)
-        if node.conversion != -1:
-            conversion = chr(node.conversion)
-            if conversion not in "sra":
-                raise ValueError("Unknown f-string conversion.")
-            write(f"!{conversion}")
-        if node.format_spec:
-            write(":")
-            meth = getattr(self, "_fstring_" + type(node.format_spec).__name__)
-            meth(node.format_spec, write)
-        write("}")
+        with self.delimit("{", "}"):
+            expr = unparse_inner(node.value)
+            if expr.startswith("{"):
+                # Separate pair of opening brackets as "{ {"
+                self.write(" ")
+            self.write(expr)
+            if node.conversion != -1:
+                self.write(f"!{chr(node.conversion)}")
+            if node.format_spec:
+                self.write(":")
+                self._write_fstring_inner(node.format_spec, is_format_spec=True)

    def visit_Name(self, node):
        self.write(node.id)
@@ -1217,8 +1351,6 @@ class _Unparser(NodeVisitor):
                .replace("inf", _INFSTR)
                .replace("nan", f"({_INFSTR}-{_INFSTR})")
            )
-        elif self._avoid_backslashes and isinstance(value, str):
-            self._write_str_avoiding_backslashes(value)
        else:
            self.write(repr(value))

@@ -1320,7 +1452,11 @@ class _Unparser(NodeVisitor):
            )

    def visit_Tuple(self, node):
-        with self.delimit("(", ")"):
+        with self.delimit_if(
+            "(",
+            ")",
+            len(node.elts) == 0 or self.get_precedence(node) > _Precedence.TUPLE
+        ):
            self.items_view(self.traverse, node.elts)

    unop = {"Invert": "~", "Not": "not", "UAdd": "+", "USub": "-"}
@@ -1336,7 +1472,7 @@ class _Unparser(NodeVisitor):
        operator_precedence = self.unop_precedence[operator]
        with self.require_parens(operator_precedence, node):
            self.write(operator)
-            # factor prefixes (+, -, ~) shouldn't be seperated
+            # factor prefixes (+, -, ~) shouldn't be separated
            # from the value they belong, (e.g: +1 instead of + 1)
            if operator_precedence is not _Precedence.FACTOR:
                self.write(" ")
@@ -1461,20 +1597,17 @@ class _Unparser(NodeVisitor):
                self.traverse(e)

    def visit_Subscript(self, node):
-        def is_simple_tuple(slice_value):
-            # when unparsing a non-empty tuple, the parentheses can be safely
-            # omitted if there aren't any elements that explicitly requires
-            # parentheses (such as starred expressions).
+        def is_non_empty_tuple(slice_value):
            return (
                isinstance(slice_value, Tuple)
                and slice_value.elts
-                and not any(isinstance(elt, Starred) for elt in slice_value.elts)
            )

        self.set_precedence(_Precedence.ATOM, node.value)
        self.traverse(node.value)
        with self.delimit("[", "]"):
-            if is_simple_tuple(node.slice):
+            if is_non_empty_tuple(node.slice):
+                # parentheses can be omitted if the tuple isn't empty
                self.items_view(self.traverse, node.slice.elts)
            else:
                self.traverse(node.slice)
@@ -1571,8 +1704,11 @@ class _Unparser(NodeVisitor):

    def visit_Lambda(self, node):
        with self.require_parens(_Precedence.TEST, node):
-            self.write("lambda ")
-            self.traverse(node.args)
+            self.write("lambda")
+            with self.buffered() as buffer:
+                self.traverse(node.args)
+            if buffer:
+                self.write(" ", *buffer)
            self.write(": ")
            self.set_precedence(_Precedence.TEST, node.body)
            self.traverse(node.body)
@@ -1681,12 +1817,27 @@ def unparse(ast_obj):
    return unparser.visit(ast_obj)


+_deprecated_globals = {
+    name: globals().pop(name)
+    for name in ('Num', 'Str', 'Bytes', 'NameConstant', 'Ellipsis')
+}
+
+def __getattr__(name):
+    if name in _deprecated_globals:
+        globals()[name] = value = _deprecated_globals[name]
+        import warnings
+        warnings._deprecated(
+            f"ast.{name}", message=_DEPRECATED_CLASS_MESSAGE, remove=(3, 14)
+        )
+        return value
+    raise AttributeError(f"module 'ast' has no attribute '{name}'")
+
+
 def main():
    import argparse

    parser = argparse.ArgumentParser(prog='python -m ast')
-    parser.add_argument('infile', type=argparse.FileType(mode='rb'), nargs='?',
-                        default='-',
+    parser.add_argument('infile', nargs='?', default='-',
                        help='the file to parse; defaults to stdin')
    parser.add_argument('-m', '--mode', default='exec',
                        choices=('exec', 'single', 'eval', 'func_type'),
@@ -1700,9 +1851,14 @@ def main():
                        help='indentation of nodes (number of spaces)')
    args = parser.parse_args()

-    with args.infile as infile:
-        source = infile.read()
-    tree = parse(source, args.infile.name, args.mode, type_comments=args.no_type_comments)
+    if args.infile == '-':
+        name = '<stdin>'
+        source = sys.stdin.buffer.read()
+    else:
+        name = args.infile
+        with open(args.infile, 'rb') as infile:
+            source = infile.read()
+    tree = parse(source, name, args.mode, type_comments=args.no_type_comments)
    print(dump(tree, include_attributes=args.include_attributes, indent=args.indent))

 if __name__ == '__main__':
--- a/Lib/asyncio/init.py
+++ b/Lib/asyncio/init.py
@@ -1,22 +1,14 @@
 """The asyncio package, tracking PEP 3156."""

 # flake8: noqa
+
 import sys

-import selectors
-# XXX RustPython TODO: _overlapped
-if sys.platform == 'win32' and False:
-    # Similar thing for _overlapped.
-    try:
-        from . import _overlapped
-    except ImportError:
-        import _overlapped  # Will also be exported.
-
-
 # This relies on each of the submodules having an __all__ variable.
 from .base_events import *
 from .coroutines import *
 from .events import *
+from .exceptions import *
 from .futures import *
 from .locks import *
 from .protocols import *
@@ -25,11 +17,15 @@ from .queues import *
 from .streams import *
 from .subprocess import *
 from .tasks import *
+from .taskgroups import *
+from .timeouts import *
+from .threads import *
 from .transports import *

 __all__ = (base_events.__all__ +
           coroutines.__all__ +
           events.__all__ +
+           exceptions.__all__ +
           futures.__all__ +
           locks.__all__ +
           protocols.__all__ +
@@ -38,6 +34,9 @@ __all__ = (base_events.__all__ +
           streams.__all__ +
           subprocess.__all__ +
           tasks.__all__ +
+           taskgroups.__all__ +
+           threads.__all__ +
+           timeouts.__all__ +
           transports.__all__)

 if sys.platform == 'win32':  # pragma: no cover
--- a/Lib/asyncio/main.py
+++ b/Lib/asyncio/main.py
@@ -0,0 +1,125 @@
+import ast
+import asyncio
+import code
+import concurrent.futures
+import inspect
+import sys
+import threading
+import types
+import warnings
+
+from . import futures
+
+
+class AsyncIOInteractiveConsole(code.InteractiveConsole):
+
+    def __init__(self, locals, loop):
+        super().__init__(locals)
+        self.compile.compiler.flags |= ast.PyCF_ALLOW_TOP_LEVEL_AWAIT
+
+        self.loop = loop
+
+    def runcode(self, code):
+        future = concurrent.futures.Future()
+
+        def callback():
+            global repl_future
+            global repl_future_interrupted
+
+            repl_future = None
+            repl_future_interrupted = False
+
+            func = types.FunctionType(code, self.locals)
+            try:
+                coro = func()
+            except SystemExit:
+                raise
+            except KeyboardInterrupt as ex:
+                repl_future_interrupted = True
+                future.set_exception(ex)
+                return
+            except BaseException as ex:
+                future.set_exception(ex)
+                return
+
+            if not inspect.iscoroutine(coro):
+                future.set_result(coro)
+                return
+
+            try:
+                repl_future = self.loop.create_task(coro)
+                futures._chain_future(repl_future, future)
+            except BaseException as exc:
+                future.set_exception(exc)
+
+        loop.call_soon_threadsafe(callback)
+
+        try:
+            return future.result()
+        except SystemExit:
+            raise
+        except BaseException:
+            if repl_future_interrupted:
+                self.write("\nKeyboardInterrupt\n")
+            else:
+                self.showtraceback()
+
+
+class REPLThread(threading.Thread):
+
+    def run(self):
+        try:
+            banner = (
+                f'asyncio REPL {sys.version} on {sys.platform}\n'
+                f'Use "await" directly instead of "asyncio.run()".\n'
+                f'Type "help", "copyright", "credits" or "license" '
+                f'for more information.\n'
+                f'{getattr(sys, "ps1", ">>> ")}import asyncio'
+            )
+
+            console.interact(
+                banner=banner,
+                exitmsg='exiting asyncio REPL...')
+        finally:
+            warnings.filterwarnings(
+                'ignore',
+                message=r'^coroutine .* was never awaited$',
+                category=RuntimeWarning)
+
+            loop.call_soon_threadsafe(loop.stop)
+
+
+if __name__ == '__main__':
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+
+    repl_locals = {'asyncio': asyncio}
+    for key in {'__name__', '__package__',
+                '__loader__', '__spec__',
+                '__builtins__', '__file__'}:
+        repl_locals[key] = locals()[key]
+
+    console = AsyncIOInteractiveConsole(repl_locals, loop)
+
+    repl_future = None
+    repl_future_interrupted = False
+
+    try:
+        import readline  # NoQA
+    except ImportError:
+        pass
+
+    repl_thread = REPLThread()
+    repl_thread.daemon = True
+    repl_thread.start()
+
+    while True:
+        try:
+            loop.run_forever()
+        except KeyboardInterrupt:
+            if repl_future and not repl_future.done():
+                repl_future.cancel()
+                repl_future_interrupted = True
+            continue
+        else:
+            break
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
--- a/Lib/asyncio/base_futures.py
+++ b/Lib/asyncio/base_futures.py
@@ -1,18 +1,8 @@
-__all__ = []
+__all__ = ()

-import concurrent.futures._base
 import reprlib

-from . import events
-
-Error = concurrent.futures._base.Error
-CancelledError = concurrent.futures.CancelledError
-TimeoutError = concurrent.futures.TimeoutError
-
-
-class InvalidStateError(Error):
-    """The operation is not allowed in this state."""
-
+from . import format_helpers

 # States for Future.
 _PENDING = 'PENDING'
@@ -38,17 +28,17 @@ def _format_callbacks(cb):
        cb = ''

    def format_cb(callback):
-        return events._format_callback_source(callback, ())
+        return format_helpers._format_callback_source(callback, ())

    if size == 1:
-        cb = format_cb(cb[0])
+        cb = format_cb(cb[0][0])
    elif size == 2:
-        cb = '{}, {}'.format(format_cb(cb[0]), format_cb(cb[1]))
+        cb = '{}, {}'.format(format_cb(cb[0][0]), format_cb(cb[1][0]))
    elif size > 2:
-        cb = '{}, <{} more>, {}'.format(format_cb(cb[0]),
+        cb = '{}, <{} more>, {}'.format(format_cb(cb[0][0]),
                                        size - 2,
-                                        format_cb(cb[-1]))
-    return 'cb=[%s]' % cb
+                                        format_cb(cb[-1][0]))
+    return f'cb=[{cb}]'


 def _future_repr_info(future):
@@ -57,15 +47,21 @@ def _future_repr_info(future):
    info = [future._state.lower()]
    if future._state == _FINISHED:
        if future._exception is not None:
-            info.append('exception={!r}'.format(future._exception))
+            info.append(f'exception={future._exception!r}')
        else:
            # use reprlib to limit the length of the output, especially
            # for very long strings
            result = reprlib.repr(future._result)
-            info.append('result={}'.format(result))
+            info.append(f'result={result}')
    if future._callbacks:
        info.append(_format_callbacks(future._callbacks))
    if future._source_traceback:
        frame = future._source_traceback[-1]
-        info.append('created at %s:%s' % (frame[0], frame[1]))
+        info.append(f'created at {frame[0]}:{frame[1]}')
    return info
+
+
+@reprlib.recursive_repr()
+def _future_repr(future):
+    info = ' '.join(_future_repr_info(future))
+    return f'<{future.__class__.__name__} {info}>'
--- a/Lib/asyncio/base_subprocess.py
+++ b/Lib/asyncio/base_subprocess.py
@@ -2,10 +2,8 @@ import collections
 import subprocess
 import warnings

-from . import compat
 from . import protocols
 from . import transports
-from .coroutines import coroutine
 from .log import logger


@@ -59,9 +57,9 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
        if self._closed:
            info.append('closed')
        if self._pid is not None:
-            info.append('pid=%s' % self._pid)
+            info.append(f'pid={self._pid}')
        if self._returncode is not None:
-            info.append('returncode=%s' % self._returncode)
+            info.append(f'returncode={self._returncode}')
        elif self._pid is not None:
            info.append('running')
        else:
@@ -69,19 +67,19 @@ class BaseSubprocessTransport(transports.SubprocessTransport):

        stdin = self._pipes.get(0)
        if stdin is not None:
-            info.append('stdin=%s' % stdin.pipe)
+            info.append(f'stdin={stdin.pipe}')

        stdout = self._pipes.get(1)
        stderr = self._pipes.get(2)
        if stdout is not None and stderr is stdout:
-            info.append('stdout=stderr=%s' % stdout.pipe)
+            info.append(f'stdout=stderr={stdout.pipe}')
        else:
            if stdout is not None:
-                info.append('stdout=%s' % stdout.pipe)
+                info.append(f'stdout={stdout.pipe}')
            if stderr is not None:
-                info.append('stderr=%s' % stderr.pipe)
+                info.append(f'stderr={stderr.pipe}')

-        return '<%s>' % ' '.join(info)
+        return '<{}>'.format(' '.join(info))

    def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs):
        raise NotImplementedError
@@ -105,12 +103,13 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
                continue
            proto.pipe.close()

-        if (self._proc is not None
-        # the child process finished?
-        and self._returncode is None
-        # the child process finished but the transport was not notified yet?
-        and self._proc.poll() is None
-        ):
+        if (self._proc is not None and
+                # has the child process finished?
+                self._returncode is None and
+                # the child process has finished, but the
+                # transport hasn't been notified yet?
+                self._proc.poll() is None):
+
            if self._loop.get_debug():
                logger.warning('Close running child process: kill %r', self)

@@ -121,15 +120,10 @@ class BaseSubprocessTransport(transports.SubprocessTransport):

            # Don't clear the _proc reference yet: _post_init() may still run

-    # On Python 3.3 and older, objects with a destructor part of a reference
-    # cycle are never destroyed. It's not more the case on Python 3.4 thanks
-    # to the PEP 442.
-    if compat.PY34:
-        def __del__(self):
-            if not self._closed:
-                warnings.warn("unclosed transport %r" % self, ResourceWarning,
-                              source=self)
-                self.close()
+    def __del__(self, _warn=warnings.warn):
+        if not self._closed:
+            _warn(f"unclosed transport {self!r}", ResourceWarning, source=self)
+            self.close()

    def get_pid(self):
        return self._pid
@@ -159,26 +153,25 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
        self._check_proc()
        self._proc.kill()

-    @coroutine
-    def _connect_pipes(self, waiter):
+    async def _connect_pipes(self, waiter):
        try:
            proc = self._proc
            loop = self._loop

            if proc.stdin is not None:
-                _, pipe = yield from loop.connect_write_pipe(
+                _, pipe = await loop.connect_write_pipe(
                    lambda: WriteSubprocessPipeProto(self, 0),
                    proc.stdin)
                self._pipes[0] = pipe

            if proc.stdout is not None:
-                _, pipe = yield from loop.connect_read_pipe(
+                _, pipe = await loop.connect_read_pipe(
                    lambda: ReadSubprocessPipeProto(self, 1),
                    proc.stdout)
                self._pipes[1] = pipe

            if proc.stderr is not None:
-                _, pipe = yield from loop.connect_read_pipe(
+                _, pipe = await loop.connect_read_pipe(
                    lambda: ReadSubprocessPipeProto(self, 2),
                    proc.stderr)
                self._pipes[2] = pipe
@@ -189,7 +182,9 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
            for callback, data in self._pending_calls:
                loop.call_soon(callback, *data)
            self._pending_calls = None
-        except Exception as exc:
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
            if waiter is not None and not waiter.cancelled():
                waiter.set_exception(exc)
        else:
@@ -213,24 +208,17 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
        assert returncode is not None, returncode
        assert self._returncode is None, self._returncode
        if self._loop.get_debug():
-            logger.info('%r exited with return code %r',
-                        self, returncode)
+            logger.info('%r exited with return code %r', self, returncode)
        self._returncode = returncode
        if self._proc.returncode is None:
            # asyncio uses a child watcher: copy the status into the Popen
            # object. On Python 3.6, it is required to avoid a ResourceWarning.
            self._proc.returncode = returncode
        self._call(self._protocol.process_exited)
+
        self._try_finish()

-        # wake up futures waiting for wait()
-        for waiter in self._exit_waiters:
-            if not waiter.cancelled():
-                waiter.set_result(returncode)
-        self._exit_waiters = None
-
-    @coroutine
-    def _wait(self):
+    async def _wait(self):
        """Wait until the process exit and return the process return code.

        This method is a coroutine."""
@@ -239,7 +227,7 @@ class BaseSubprocessTransport(transports.SubprocessTransport):

        waiter = self._loop.create_future()
        self._exit_waiters.append(waiter)
-        return (yield from waiter)
+        return await waiter

    def _try_finish(self):
        assert not self._finished
@@ -254,6 +242,11 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
        try:
            self._protocol.connection_lost(exc)
        finally:
+            # wake up futures waiting for wait()
+            for waiter in self._exit_waiters:
+                if not waiter.cancelled():
+                    waiter.set_result(self._returncode)
+            self._exit_waiters = None
            self._loop = None
            self._proc = None
            self._protocol = None
@@ -271,8 +264,7 @@ class WriteSubprocessPipeProto(protocols.BaseProtocol):
        self.pipe = transport

    def __repr__(self):
-        return ('<%s fd=%s pipe=%r>'
-                % (self.__class__.__name__, self.fd, self.pipe))
+        return f'<{self.__class__.__name__} fd={self.fd} pipe={self.pipe!r}>'

    def connection_lost(self, exc):
        self.disconnected = True
--- a/Lib/asyncio/base_tasks.py
+++ b/Lib/asyncio/base_tasks.py
@@ -1,4 +1,5 @@
 import linecache
+import reprlib
 import traceback

 from . import base_futures
@@ -8,25 +9,42 @@ from . import coroutines
 def _task_repr_info(task):
    info = base_futures._future_repr_info(task)

-    if task._must_cancel:
+    if task.cancelling() and not task.done():
        # replace status
        info[0] = 'cancelling'

-    coro = coroutines._format_coroutine(task._coro)
-    info.insert(1, 'coro=<%s>' % coro)
+    info.insert(1, 'name=%r' % task.get_name())

    if task._fut_waiter is not None:
-        info.insert(2, 'wait_for=%r' % task._fut_waiter)
+        info.insert(2, f'wait_for={task._fut_waiter!r}')
+
+    if task._coro:
+        coro = coroutines._format_coroutine(task._coro)
+        info.insert(2, f'coro=<{coro}>')
+
    return info


+@reprlib.recursive_repr()
+def _task_repr(task):
+    info = ' '.join(_task_repr_info(task))
+    return f'<{task.__class__.__name__} {info}>'
+
+
 def _task_get_stack(task, limit):
    frames = []
-    try:
-        # 'async def' coroutines
+    if hasattr(task._coro, 'cr_frame'):
+        # case 1: 'async def' coroutines
        f = task._coro.cr_frame
-    except AttributeError:
+    elif hasattr(task._coro, 'gi_frame'):
+        # case 2: legacy coroutines
        f = task._coro.gi_frame
+    elif hasattr(task._coro, 'ag_frame'):
+        # case 3: async generators
+        f = task._coro.ag_frame
+    else:
+        # case 4: unknown objects
+        f = None
    if f is not None:
        while f is not None:
            if limit is not None:
@@ -61,15 +79,15 @@ def _task_print_stack(task, limit, file):
            linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        extracted_list.append((filename, lineno, name, line))
+
    exc = task._exception
    if not extracted_list:
-        print('No stack for %r' % task, file=file)
+        print(f'No stack for {task!r}', file=file)
    elif exc is not None:
-        print('Traceback for %r (most recent call last):' % task,
-              file=file)
+        print(f'Traceback for {task!r} (most recent call last):', file=file)
    else:
-        print('Stack for %r (most recent call last):' % task,
-              file=file)
+        print(f'Stack for {task!r} (most recent call last):', file=file)
+
    traceback.print_list(extracted_list, file=file)
    if exc is not None:
        for line in traceback.format_exception_only(exc.__class__, exc):
--- a/Lib/asyncio/compat.py
+++ b/Lib/asyncio/compat.py
@@ -1,18 +0,0 @@
-"""Compatibility helpers for the different Python versions."""
-
-import sys
-
-PY34 = sys.version_info >= (3, 4)
-PY35 = sys.version_info >= (3, 5)
-PY352 = sys.version_info >= (3, 5, 2)
-
-
-def flatten_list_bytes(list_of_data):
-    """Concatenate a sequence of bytes-like objects."""
-    if not PY34:
-        # On Python 3.3 and older, bytes.join() doesn't handle
-        # memoryview.
-        list_of_data = (
-            bytes(data) if isinstance(data, memoryview) else data
-            for data in list_of_data)
-    return b''.join(list_of_data)
--- a/Lib/asyncio/constants.py
+++ b/Lib/asyncio/constants.py
@@ -1,7 +1,41 @@
-"""Constants."""
+# Contains code from https://github.com/MagicStack/uvloop/tree/v0.16.0
+# SPDX-License-Identifier: PSF-2.0 AND (MIT OR Apache-2.0)
+# SPDX-FileCopyrightText: Copyright (c) 2015-2021 MagicStack Inc.  http://magic.io
+
+import enum

 # After the connection is lost, log warnings after this many write()s.
 LOG_THRESHOLD_FOR_CONNLOST_WRITES = 5

 # Seconds to wait before retrying accept().
 ACCEPT_RETRY_DELAY = 1
+
+# Number of stack entries to capture in debug mode.
+# The larger the number, the slower the operation in debug mode
+# (see extract_stack() in format_helpers.py).
+DEBUG_STACK_DEPTH = 10
+
+# Number of seconds to wait for SSL handshake to complete
+# The default timeout matches that of Nginx.
+SSL_HANDSHAKE_TIMEOUT = 60.0
+
+# Number of seconds to wait for SSL shutdown to complete
+# The default timeout mimics lingering_time
+SSL_SHUTDOWN_TIMEOUT = 30.0
+
+# Used in sendfile fallback code.  We use fallback for platforms
+# that don't support sendfile, or for TLS connections.
+SENDFILE_FALLBACK_READBUFFER_SIZE = 1024 * 256
+
+FLOW_CONTROL_HIGH_WATER_SSL_READ = 256  # KiB
+FLOW_CONTROL_HIGH_WATER_SSL_WRITE = 512  # KiB
+
+# Default timeout for joining the threads in the threadpool
+THREAD_JOIN_TIMEOUT = 300
+
+# The enum should be here to break circular dependencies between
+# base_events and sslproto
+class _SendfileMode(enum.Enum):
+    UNSUPPORTED = enum.auto()
+    TRY_NATIVE = enum.auto()
+    FALLBACK = enum.auto()
--- a/Lib/asyncio/coroutines.py
+++ b/Lib/asyncio/coroutines.py
@@ -1,249 +1,16 @@
-__all__ = ['coroutine',
-           'iscoroutinefunction', 'iscoroutine']
+__all__ = 'iscoroutinefunction', 'iscoroutine'

-import functools
+import collections.abc
 import inspect
-import opcode
 import os
 import sys
-import traceback
 import types

-from . import compat
-from . import events
-from . import base_futures
-from .log import logger

-
-# Opcode of "yield from" instruction
-_YIELD_FROM = opcode.opmap['YIELD_FROM']
-
-# If you set _DEBUG to true, @coroutine will wrap the resulting
-# generator objects in a CoroWrapper instance (defined below).  That
-# instance will log a message when the generator is never iterated
-# over, which may happen when you forget to use "yield from" with a
-# coroutine call.  Note that the value of the _DEBUG flag is taken
-# when the decorator is used, so to be of any use it must be set
-# before you define your coroutines.  A downside of using this feature
-# is that tracebacks show entries for the CoroWrapper.__next__ method
-# when _DEBUG is true.
-_DEBUG = (not sys.flags.ignore_environment and
-          bool(os.environ.get('PYTHONASYNCIODEBUG')))
-
-
-try:
-    _types_coroutine = types.coroutine
-    _types_CoroutineType = types.CoroutineType
-except AttributeError:
-    # Python 3.4
-    _types_coroutine = None
-    _types_CoroutineType = None
-
-try:
-    _inspect_iscoroutinefunction = inspect.iscoroutinefunction
-except AttributeError:
-    # Python 3.4
-    _inspect_iscoroutinefunction = lambda func: False
-
-try:
-    from collections.abc import Coroutine as _CoroutineABC, \
-                                Awaitable as _AwaitableABC
-except ImportError:
-    _CoroutineABC = _AwaitableABC = None
-
-
-# Check for CPython issue #21209
-def has_yield_from_bug():
-    class MyGen:
-        def __init__(self):
-            self.send_args = None
-        def __iter__(self):
-            return self
-        def __next__(self):
-            return 42
-        def send(self, *what):
-            self.send_args = what
-            return None
-    def yield_from_gen(gen):
-        yield from gen
-    value = (1, 2, 3)
-    gen = MyGen()
-    coro = yield_from_gen(gen)
-    next(coro)
-    coro.send(value)
-    return gen.send_args != (value,)
-_YIELD_FROM_BUG = has_yield_from_bug()
-del has_yield_from_bug
-
-
-def debug_wrapper(gen):
-    # This function is called from 'sys.set_coroutine_wrapper'.
-    # We only wrap here coroutines defined via 'async def' syntax.
-    # Generator-based coroutines are wrapped in @coroutine
-    # decorator.
-    return CoroWrapper(gen, None)
-
-
-class CoroWrapper:
-    # Wrapper for coroutine object in _DEBUG mode.
-
-    def __init__(self, gen, func=None):
-        assert inspect.isgenerator(gen) or inspect.iscoroutine(gen), gen
-        self.gen = gen
-        self.func = func  # Used to unwrap @coroutine decorator
-        self._source_traceback = traceback.extract_stack(sys._getframe(1))
-        self.__name__ = getattr(gen, '__name__', None)
-        self.__qualname__ = getattr(gen, '__qualname__', None)
-
-    def __repr__(self):
-        coro_repr = _format_coroutine(self)
-        if self._source_traceback:
-            frame = self._source_traceback[-1]
-            coro_repr += ', created at %s:%s' % (frame[0], frame[1])
-        return '<%s %s>' % (self.__class__.__name__, coro_repr)
-
-    def __iter__(self):
-        return self
-
-    def __next__(self):
-        return self.gen.send(None)
-
-    if _YIELD_FROM_BUG:
-        # For for CPython issue #21209: using "yield from" and a custom
-        # generator, generator.send(tuple) unpacks the tuple instead of passing
-        # the tuple unchanged. Check if the caller is a generator using "yield
-        # from" to decide if the parameter should be unpacked or not.
-        def send(self, *value):
-            frame = sys._getframe()
-            caller = frame.f_back
-            assert caller.f_lasti >= 0
-            if caller.f_code.co_code[caller.f_lasti] != _YIELD_FROM:
-                value = value[0]
-            return self.gen.send(value)
-    else:
-        def send(self, value):
-            return self.gen.send(value)
-
-    def throw(self, type, value=None, traceback=None):
-        return self.gen.throw(type, value, traceback)
-
-    def close(self):
-        return self.gen.close()
-
-    @property
-    def gi_frame(self):
-        return self.gen.gi_frame
-
-    @property
-    def gi_running(self):
-        return self.gen.gi_running
-
-    @property
-    def gi_code(self):
-        return self.gen.gi_code
-
-    if compat.PY35:
-
-        def __await__(self):
-            cr_await = getattr(self.gen, 'cr_await', None)
-            if cr_await is not None:
-                raise RuntimeError(
-                    "Cannot await on coroutine {!r} while it's "
-                    "awaiting for {!r}".format(self.gen, cr_await))
-            return self
-
-        @property
-        def gi_yieldfrom(self):
-            return self.gen.gi_yieldfrom
-
-        @property
-        def cr_await(self):
-            return self.gen.cr_await
-
-        @property
-        def cr_running(self):
-            return self.gen.cr_running
-
-        @property
-        def cr_code(self):
-            return self.gen.cr_code
-
-        @property
-        def cr_frame(self):
-            return self.gen.cr_frame
-
-    def __del__(self):
-        # Be careful accessing self.gen.frame -- self.gen might not exist.
-        gen = getattr(self, 'gen', None)
-        frame = getattr(gen, 'gi_frame', None)
-        if frame is None:
-            frame = getattr(gen, 'cr_frame', None)
-        if frame is not None and frame.f_lasti == -1:
-            msg = '%r was never yielded from' % self
-            tb = getattr(self, '_source_traceback', ())
-            if tb:
-                tb = ''.join(traceback.format_list(tb))
-                msg += ('\nCoroutine object created at '
-                        '(most recent call last):\n')
-                msg += tb.rstrip()
-            logger.error(msg)
-
-
-def coroutine(func):
-    """Decorator to mark coroutines.
-
-    If the coroutine is not yielded from before it is destroyed,
-    an error message is logged.
-    """
-    if _inspect_iscoroutinefunction(func):
-        # In Python 3.5 that's all we need to do for coroutines
-        # defiend with "async def".
-        # Wrapping in CoroWrapper will happen via
-        # 'sys.set_coroutine_wrapper' function.
-        return func
-
-    if inspect.isgeneratorfunction(func):
-        coro = func
-    else:
-        @functools.wraps(func)
-        def coro(*args, **kw):
-            res = func(*args, **kw)
-            if (base_futures.isfuture(res) or inspect.isgenerator(res) or
-                isinstance(res, CoroWrapper)):
-                res = yield from res
-            elif _AwaitableABC is not None:
-                # If 'func' returns an Awaitable (new in 3.5) we
-                # want to run it.
-                try:
-                    await_meth = res.__await__
-                except AttributeError:
-                    pass
-                else:
-                    if isinstance(res, _AwaitableABC):
-                        res = yield from await_meth()
-            return res
-
-    if not _DEBUG:
-        if _types_coroutine is None:
-            wrapper = coro
-        else:
-            wrapper = _types_coroutine(coro)
-    else:
-        @functools.wraps(func)
-        def wrapper(*args, **kwds):
-            w = CoroWrapper(coro(*args, **kwds), func=func)
-            if w._source_traceback:
-                del w._source_traceback[-1]
-            # Python < 3.5 does not implement __qualname__
-            # on generator objects, so we set it manually.
-            # We use getattr as some callables (such as
-            # functools.partial may lack __qualname__).
-            w.__name__ = getattr(func, '__name__', None)
-            w.__qualname__ = getattr(func, '__qualname__', None)
-            return w
-
-    wrapper._is_coroutine = _is_coroutine  # For iscoroutinefunction().
-    return wrapper
+def _is_debug_mode():
+    # See: https://docs.python.org/3/library/asyncio-dev.html#asyncio-debug-mode.
+    return sys.flags.dev_mode or (not sys.flags.ignore_environment and
+                                  bool(os.environ.get('PYTHONASYNCIODEBUG')))


 # A marker for iscoroutinefunction.
@@ -252,93 +19,91 @@ _is_coroutine = object()

 def iscoroutinefunction(func):
    """Return True if func is a decorated coroutine function."""
-    return (getattr(func, '_is_coroutine', None) is _is_coroutine or
-            _inspect_iscoroutinefunction(func))
+    return (inspect.iscoroutinefunction(func) or
+            getattr(func, '_is_coroutine', None) is _is_coroutine)


-_COROUTINE_TYPES = (types.GeneratorType, CoroWrapper)
-if _CoroutineABC is not None:
-    _COROUTINE_TYPES += (_CoroutineABC,)
-if _types_CoroutineType is not None:
-    # Prioritize native coroutine check to speed-up
-    # asyncio.iscoroutine.
-    _COROUTINE_TYPES = (_types_CoroutineType,) + _COROUTINE_TYPES
+# Prioritize native coroutine check to speed-up
+# asyncio.iscoroutine.
+_COROUTINE_TYPES = (types.CoroutineType, collections.abc.Coroutine)
+_iscoroutine_typecache = set()


 def iscoroutine(obj):
    """Return True if obj is a coroutine object."""
-    return isinstance(obj, _COROUTINE_TYPES)
+    if type(obj) in _iscoroutine_typecache:
+        return True
+
+    if isinstance(obj, _COROUTINE_TYPES):
+        # Just in case we don't want to cache more than 100
+        # positive types.  That shouldn't ever happen, unless
+        # someone stressing the system on purpose.
+        if len(_iscoroutine_typecache) < 100:
+            _iscoroutine_typecache.add(type(obj))
+        return True
+    else:
+        return False


 def _format_coroutine(coro):
    assert iscoroutine(coro)

-    if not hasattr(coro, 'cr_code') and not hasattr(coro, 'gi_code'):
-        # Most likely a built-in type or a Cython coroutine.
+    def get_name(coro):
+        # Coroutines compiled with Cython sometimes don't have
+        # proper __qualname__ or __name__.  While that is a bug
+        # in Cython, asyncio shouldn't crash with an AttributeError
+        # in its __repr__ functions.
+        if hasattr(coro, '__qualname__') and coro.__qualname__:
+            coro_name = coro.__qualname__
+        elif hasattr(coro, '__name__') and coro.__name__:
+            coro_name = coro.__name__
+        else:
+            # Stop masking Cython bugs, expose them in a friendly way.
+            coro_name = f'<{type(coro).__name__} without __name__>'
+        return f'{coro_name}()'

-        # Built-in types might not have __qualname__ or __name__.
-        coro_name = getattr(
-            coro, '__qualname__',
-            getattr(coro, '__name__', type(coro).__name__))
-        coro_name = '{}()'.format(coro_name)
-
-        running = False
+    def is_running(coro):
        try:
-            running = coro.cr_running
+            return coro.cr_running
        except AttributeError:
            try:
-                running = coro.gi_running
+                return coro.gi_running
            except AttributeError:
-                pass
+                return False

-        if running:
-            return '{} running'.format(coro_name)
+    coro_code = None
+    if hasattr(coro, 'cr_code') and coro.cr_code:
+        coro_code = coro.cr_code
+    elif hasattr(coro, 'gi_code') and coro.gi_code:
+        coro_code = coro.gi_code
+
+    coro_name = get_name(coro)
+
+    if not coro_code:
+        # Built-in types might not have __qualname__ or __name__.
+        if is_running(coro):
+            return f'{coro_name} running'
        else:
            return coro_name

-    coro_name = None
-    if isinstance(coro, CoroWrapper):
-        func = coro.func
-        coro_name = coro.__qualname__
-        if coro_name is not None:
-            coro_name = '{}()'.format(coro_name)
-    else:
-        func = coro
-
-    if coro_name is None:
-        coro_name = events._format_callback(func, (), {})
-
-    try:
-        coro_code = coro.gi_code
-    except AttributeError:
-        coro_code = coro.cr_code
-
-    try:
+    coro_frame = None
+    if hasattr(coro, 'gi_frame') and coro.gi_frame:
        coro_frame = coro.gi_frame
-    except AttributeError:
+    elif hasattr(coro, 'cr_frame') and coro.cr_frame:
        coro_frame = coro.cr_frame

-    filename = coro_code.co_filename
+    # If Cython's coroutine has a fake code object without proper
+    # co_filename -- expose that.
+    filename = coro_code.co_filename or '<empty co_filename>'
+
    lineno = 0
-    if (isinstance(coro, CoroWrapper) and
-            not inspect.isgeneratorfunction(coro.func) and
-            coro.func is not None):
-        source = events._get_function_source(coro.func)
-        if source is not None:
-            filename, lineno = source
-        if coro_frame is None:
-            coro_repr = ('%s done, defined at %s:%s'
-                         % (coro_name, filename, lineno))
-        else:
-            coro_repr = ('%s running, defined at %s:%s'
-                         % (coro_name, filename, lineno))
-    elif coro_frame is not None:
+
+    if coro_frame is not None:
        lineno = coro_frame.f_lineno
-        coro_repr = ('%s running at %s:%s'
-                     % (coro_name, filename, lineno))
+        coro_repr = f'{coro_name} running at {filename}:{lineno}'
+
    else:
        lineno = coro_code.co_firstlineno
-        coro_repr = ('%s done, defined at %s:%s'
-                     % (coro_name, filename, lineno))
+        coro_repr = f'{coro_name} done, defined at {filename}:{lineno}'

    return coro_repr
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -1,96 +1,50 @@
 """Event loop and event loop policy."""

-__all__ = ['AbstractEventLoopPolicy',
-           'AbstractEventLoop', 'AbstractServer',
-           'Handle', 'TimerHandle',
-           'get_event_loop_policy', 'set_event_loop_policy',
-           'get_event_loop', 'set_event_loop', 'new_event_loop',
-           'get_child_watcher', 'set_child_watcher',
-           '_set_running_loop', 'get_running_loop',
-           '_get_running_loop',
-           ]
+# Contains code from https://github.com/MagicStack/uvloop/tree/v0.16.0
+# SPDX-License-Identifier: PSF-2.0 AND (MIT OR Apache-2.0)
+# SPDX-FileCopyrightText: Copyright (c) 2015-2021 MagicStack Inc.  http://magic.io

-import functools
-import inspect
-import reprlib
+__all__ = (
+    'AbstractEventLoopPolicy',
+    'AbstractEventLoop', 'AbstractServer',
+    'Handle', 'TimerHandle',
+    'get_event_loop_policy', 'set_event_loop_policy',
+    'get_event_loop', 'set_event_loop', 'new_event_loop',
+    'get_child_watcher', 'set_child_watcher',
+    '_set_running_loop', 'get_running_loop',
+    '_get_running_loop',
+)
+
+import contextvars
+import os
+import signal
 import socket
 import subprocess
 import sys
 import threading
-import traceback

-from asyncio import compat
-
-
-def _get_function_source(func):
-    if compat.PY34:
-        func = inspect.unwrap(func)
-    elif hasattr(func, '__wrapped__'):
-        func = func.__wrapped__
-    if inspect.isfunction(func):
-        code = func.__code__
-        return (code.co_filename, code.co_firstlineno)
-    if isinstance(func, functools.partial):
-        return _get_function_source(func.func)
-    if compat.PY34 and isinstance(func, functools.partialmethod):
-        return _get_function_source(func.func)
-    return None
-
-
-def _format_args_and_kwargs(args, kwargs):
-    """Format function arguments and keyword arguments.
-
-    Special case for a single parameter: ('hello',) is formatted as ('hello').
-    """
-    # use reprlib to limit the length of the output
-    items = []
-    if args:
-        items.extend(reprlib.repr(arg) for arg in args)
-    if kwargs:
-        items.extend('{}={}'.format(k, reprlib.repr(v))
-                     for k, v in kwargs.items())
-    return '(' + ', '.join(items) + ')'
-
-
-def _format_callback(func, args, kwargs, suffix=''):
-    if isinstance(func, functools.partial):
-        suffix = _format_args_and_kwargs(args, kwargs) + suffix
-        return _format_callback(func.func, func.args, func.keywords, suffix)
-
-    if hasattr(func, '__qualname__'):
-        func_repr = getattr(func, '__qualname__')
-    elif hasattr(func, '__name__'):
-        func_repr = getattr(func, '__name__')
-    else:
-        func_repr = repr(func)
-
-    func_repr += _format_args_and_kwargs(args, kwargs)
-    if suffix:
-        func_repr += suffix
-    return func_repr
-
-def _format_callback_source(func, args):
-    func_repr = _format_callback(func, args, None)
-    source = _get_function_source(func)
-    if source:
-        func_repr += ' at %s:%s' % source
-    return func_repr
+from . import format_helpers


 class Handle:
    """Object returned by callback registration methods."""

    __slots__ = ('_callback', '_args', '_cancelled', '_loop',
-                 '_source_traceback', '_repr', '__weakref__')
+                 '_source_traceback', '_repr', '__weakref__',
+                 '_context')

-    def __init__(self, callback, args, loop):
+    def __init__(self, callback, args, loop, context=None):
+        if context is None:
+            context = contextvars.copy_context()
+        self._context = context
        self._loop = loop
        self._callback = callback
        self._args = args
        self._cancelled = False
        self._repr = None
        if self._loop.get_debug():
-            self._source_traceback = traceback.extract_stack(sys._getframe(1))
+            self._source_traceback = format_helpers.extract_stack(
+                sys._getframe(1))
        else:
            self._source_traceback = None

@@ -99,17 +53,21 @@ class Handle:
        if self._cancelled:
            info.append('cancelled')
        if self._callback is not None:
-            info.append(_format_callback_source(self._callback, self._args))
+            info.append(format_helpers._format_callback_source(
+                self._callback, self._args))
        if self._source_traceback:
            frame = self._source_traceback[-1]
-            info.append('created at %s:%s' % (frame[0], frame[1]))
+            info.append(f'created at {frame[0]}:{frame[1]}')
        return info

    def __repr__(self):
        if self._repr is not None:
            return self._repr
        info = self._repr_info()
-        return '<%s>' % ' '.join(info)
+        return '<{}>'.format(' '.join(info))
+
+    def get_context(self):
+        return self._context

    def cancel(self):
        if not self._cancelled:
@@ -122,12 +80,18 @@ class Handle:
            self._callback = None
            self._args = None

+    def cancelled(self):
+        return self._cancelled
+
    def _run(self):
        try:
-            self._callback(*self._args)
-        except Exception as exc:
-            cb = _format_callback_source(self._callback, self._args)
-            msg = 'Exception in callback {}'.format(cb)
+            self._context.run(self._callback, *self._args)
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
+            cb = format_helpers._format_callback_source(
+                self._callback, self._args)
+            msg = f'Exception in callback {cb}'
            context = {
                'message': msg,
                'exception': exc,
@@ -144,9 +108,8 @@ class TimerHandle(Handle):

    __slots__ = ['_scheduled', '_when']

-    def __init__(self, when, callback, args, loop):
-        assert when is not None
-        super().__init__(callback, args, loop)
+    def __init__(self, when, callback, args, loop, context=None):
+        super().__init__(callback, args, loop, context)
        if self._source_traceback:
            del self._source_traceback[-1]
        self._when = when
@@ -155,27 +118,31 @@ class TimerHandle(Handle):
    def _repr_info(self):
        info = super()._repr_info()
        pos = 2 if self._cancelled else 1
-        info.insert(pos, 'when=%s' % self._when)
+        info.insert(pos, f'when={self._when}')
        return info

    def __hash__(self):
        return hash(self._when)

    def __lt__(self, other):
-        return self._when < other._when
+        if isinstance(other, TimerHandle):
+            return self._when < other._when
+        return NotImplemented

    def __le__(self, other):
-        if self._when < other._when:
-            return True
-        return self.__eq__(other)
+        if isinstance(other, TimerHandle):
+            return self._when < other._when or self.__eq__(other)
+        return NotImplemented

    def __gt__(self, other):
-        return self._when > other._when
+        if isinstance(other, TimerHandle):
+            return self._when > other._when
+        return NotImplemented

    def __ge__(self, other):
-        if self._when > other._when:
-            return True
-        return self.__eq__(other)
+        if isinstance(other, TimerHandle):
+            return self._when > other._when or self.__eq__(other)
+        return NotImplemented

    def __eq__(self, other):
        if isinstance(other, TimerHandle):
@@ -185,26 +152,60 @@ class TimerHandle(Handle):
                    self._cancelled == other._cancelled)
        return NotImplemented

-    def __ne__(self, other):
-        equal = self.__eq__(other)
-        return NotImplemented if equal is NotImplemented else not equal
-
    def cancel(self):
        if not self._cancelled:
            self._loop._timer_handle_cancelled(self)
        super().cancel()

+    def when(self):
+        """Return a scheduled callback time.
+
+        The time is an absolute timestamp, using the same time
+        reference as loop.time().
+        """
+        return self._when
+

 class AbstractServer:
    """Abstract server returned by create_server()."""

    def close(self):
        """Stop serving.  This leaves existing connections open."""
-        return NotImplemented
+        raise NotImplementedError

-    def wait_closed(self):
+    def get_loop(self):
+        """Get the event loop the Server object is attached to."""
+        raise NotImplementedError
+
+    def is_serving(self):
+        """Return True if the server is accepting connections."""
+        raise NotImplementedError
+
+    async def start_serving(self):
+        """Start accepting connections.
+
+        This method is idempotent, so it can be called when
+        the server is already being serving.
+        """
+        raise NotImplementedError
+
+    async def serve_forever(self):
+        """Start accepting connections until the coroutine is cancelled.
+
+        The server is closed when the coroutine is cancelled.
+        """
+        raise NotImplementedError
+
+    async def wait_closed(self):
        """Coroutine to wait until service is closed."""
-        return NotImplemented
+        raise NotImplementedError
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, *exc):
+        self.close()
+        await self.wait_closed()


 class AbstractEventLoop:
@@ -250,23 +251,27 @@ class AbstractEventLoop:
        """
        raise NotImplementedError

-    def shutdown_asyncgens(self):
+    async def shutdown_asyncgens(self):
        """Shutdown all active asynchronous generators."""
        raise NotImplementedError

+    async def shutdown_default_executor(self):
+        """Schedule the shutdown of the default executor."""
+        raise NotImplementedError
+
    # Methods scheduling callbacks.  All these return Handles.

    def _timer_handle_cancelled(self, handle):
        """Notification that a TimerHandle has been cancelled."""
        raise NotImplementedError

-    def call_soon(self, callback, *args):
-        return self.call_later(0, callback, *args)
+    def call_soon(self, callback, *args, context=None):
+        return self.call_later(0, callback, *args, context=context)

-    def call_later(self, delay, callback, *args):
+    def call_later(self, delay, callback, *args, context=None):
        raise NotImplementedError

-    def call_at(self, when, callback, *args):
+    def call_at(self, when, callback, *args, context=None):
        raise NotImplementedError

    def time(self):
@@ -277,12 +282,12 @@ class AbstractEventLoop:

    # Method scheduling a coroutine object: create a task.

-    def create_task(self, coro):
+    def create_task(self, coro, *, name=None, context=None):
        raise NotImplementedError

    # Methods for interacting with threads.

-    def call_soon_threadsafe(self, callback, *args):
+    def call_soon_threadsafe(self, callback, *args, context=None):
        raise NotImplementedError

    def run_in_executor(self, executor, func, *args):
@@ -293,21 +298,31 @@ class AbstractEventLoop:

    # Network I/O methods returning Futures.

-    def getaddrinfo(self, host, port, *, family=0, type=0, proto=0, flags=0):
+    async def getaddrinfo(self, host, port, *,
+                          family=0, type=0, proto=0, flags=0):
        raise NotImplementedError

-    def getnameinfo(self, sockaddr, flags=0):
+    async def getnameinfo(self, sockaddr, flags=0):
        raise NotImplementedError

-    def create_connection(self, protocol_factory, host=None, port=None, *,
-                          ssl=None, family=0, proto=0, flags=0, sock=None,
-                          local_addr=None, server_hostname=None):
+    async def create_connection(
+            self, protocol_factory, host=None, port=None,
+            *, ssl=None, family=0, proto=0,
+            flags=0, sock=None, local_addr=None,
+            server_hostname=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
+            happy_eyeballs_delay=None, interleave=None):
        raise NotImplementedError

-    def create_server(self, protocol_factory, host=None, port=None, *,
-                      family=socket.AF_UNSPEC, flags=socket.AI_PASSIVE,
-                      sock=None, backlog=100, ssl=None, reuse_address=None,
-                      reuse_port=None):
+    async def create_server(
+            self, protocol_factory, host=None, port=None,
+            *, family=socket.AF_UNSPEC,
+            flags=socket.AI_PASSIVE, sock=None, backlog=100,
+            ssl=None, reuse_address=None, reuse_port=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
+            start_serving=True):
        """A coroutine which creates a TCP server bound to host and port.

        The return value is a Server object which can be used to stop
@@ -315,8 +330,8 @@ class AbstractEventLoop:

        If host is an empty string or None all interfaces are assumed
        and a list of multiple sockets will be returned (most likely
-        one for IPv4 and another one for IPv6). The host parameter can also be a
-        sequence (e.g. list) of hosts to bind to.
+        one for IPv4 and another one for IPv6). The host parameter can also be
+        a sequence (e.g. list) of hosts to bind to.

        family can be set to either AF_INET or AF_INET6 to force the
        socket to use IPv4 or IPv6. If not set it will be determined
@@ -342,22 +357,62 @@ class AbstractEventLoop:
        the same port as other existing endpoints are bound to, so long as
        they all set this flag when being created. This option is not
        supported on Windows.
+
+        ssl_handshake_timeout is the time in seconds that an SSL server
+        will wait for completion of the SSL handshake before aborting the
+        connection. Default is 60s.
+
+        ssl_shutdown_timeout is the time in seconds that an SSL server
+        will wait for completion of the SSL shutdown procedure
+        before aborting the connection. Default is 30s.
+
+        start_serving set to True (default) causes the created server
+        to start accepting connections immediately.  When set to False,
+        the user should await Server.start_serving() or Server.serve_forever()
+        to make the server to start accepting connections.
        """
        raise NotImplementedError

-    def create_unix_connection(self, protocol_factory, path, *,
-                               ssl=None, sock=None,
-                               server_hostname=None):
+    async def sendfile(self, transport, file, offset=0, count=None,
+                       *, fallback=True):
+        """Send a file through a transport.
+
+        Return an amount of sent bytes.
+        """
        raise NotImplementedError

-    def create_unix_server(self, protocol_factory, path, *,
-                           sock=None, backlog=100, ssl=None):
+    async def start_tls(self, transport, protocol, sslcontext, *,
+                        server_side=False,
+                        server_hostname=None,
+                        ssl_handshake_timeout=None,
+                        ssl_shutdown_timeout=None):
+        """Upgrade a transport to TLS.
+
+        Return a new transport that *protocol* should start using
+        immediately.
+        """
+        raise NotImplementedError
+
+    async def create_unix_connection(
+            self, protocol_factory, path=None, *,
+            ssl=None, sock=None,
+            server_hostname=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
+        raise NotImplementedError
+
+    async def create_unix_server(
+            self, protocol_factory, path=None, *,
+            sock=None, backlog=100, ssl=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None,
+            start_serving=True):
        """A coroutine which creates a UNIX Domain Socket server.

        The return value is a Server object, which can be used to stop
        the service.

-        path is a str, representing a file systsem path to bind the
+        path is a str, representing a file system path to bind the
        server socket to.

        sock can optionally be specified in order to use a preexisting
@@ -368,14 +423,40 @@ class AbstractEventLoop:

        ssl can be set to an SSLContext to enable SSL over the
        accepted connections.
+
+        ssl_handshake_timeout is the time in seconds that an SSL server
+        will wait for the SSL handshake to complete (defaults to 60s).
+
+        ssl_shutdown_timeout is the time in seconds that an SSL server
+        will wait for the SSL shutdown to finish (defaults to 30s).
+
+        start_serving set to True (default) causes the created server
+        to start accepting connections immediately.  When set to False,
+        the user should await Server.start_serving() or Server.serve_forever()
+        to make the server to start accepting connections.
        """
        raise NotImplementedError

-    def create_datagram_endpoint(self, protocol_factory,
-                                 local_addr=None, remote_addr=None, *,
-                                 family=0, proto=0, flags=0,
-                                 reuse_address=None, reuse_port=None,
-                                 allow_broadcast=None, sock=None):
+    async def connect_accepted_socket(
+            self, protocol_factory, sock,
+            *, ssl=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
+        """Handle an accepted connection.
+
+        This is used by servers that accept connections outside of
+        asyncio, but use asyncio to handle connections.
+
+        This method is a coroutine.  When completed, the coroutine
+        returns a (transport, protocol) pair.
+        """
+        raise NotImplementedError
+
+    async def create_datagram_endpoint(self, protocol_factory,
+                                       local_addr=None, remote_addr=None, *,
+                                       family=0, proto=0, flags=0,
+                                       reuse_address=None, reuse_port=None,
+                                       allow_broadcast=None, sock=None):
        """A coroutine which creates a datagram endpoint.

        This method will try to establish the endpoint in the background.
@@ -383,8 +464,8 @@ class AbstractEventLoop:

        protocol_factory must be a callable returning a protocol instance.

-        socket family AF_INET or socket.AF_INET6 depending on host (or
-        family if specified), socket type SOCK_DGRAM.
+        socket family AF_INET, socket.AF_INET6 or socket.AF_UNIX depending on
+        host (or family if specified), socket type SOCK_DGRAM.

        reuse_address tells the kernel to reuse a local socket in
        TIME_WAIT state, without waiting for its natural timeout to
@@ -408,7 +489,7 @@ class AbstractEventLoop:

    # Pipes and subprocesses.

-    def connect_read_pipe(self, protocol_factory, pipe):
+    async def connect_read_pipe(self, protocol_factory, pipe):
        """Register read pipe in event loop. Set the pipe to non-blocking mode.

        protocol_factory should instantiate object with Protocol interface.
@@ -418,10 +499,10 @@ class AbstractEventLoop:
        # The reason to accept file-like object instead of just file descriptor
        # is: we need to own pipe and close it at transport finishing
        # Can got complicated errors if pass f.fileno(),
-        # close fd in pipe transport then close f and vise versa.
+        # close fd in pipe transport then close f and vice versa.
        raise NotImplementedError

-    def connect_write_pipe(self, protocol_factory, pipe):
+    async def connect_write_pipe(self, protocol_factory, pipe):
        """Register write pipe in event loop.

        protocol_factory should instantiate object with BaseProtocol interface.
@@ -431,17 +512,21 @@ class AbstractEventLoop:
        # The reason to accept file-like object instead of just file descriptor
        # is: we need to own pipe and close it at transport finishing
        # Can got complicated errors if pass f.fileno(),
-        # close fd in pipe transport then close f and vise versa.
+        # close fd in pipe transport then close f and vice versa.
        raise NotImplementedError

-    def subprocess_shell(self, protocol_factory, cmd, *, stdin=subprocess.PIPE,
-                         stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                         **kwargs):
+    async def subprocess_shell(self, protocol_factory, cmd, *,
+                               stdin=subprocess.PIPE,
+                               stdout=subprocess.PIPE,
+                               stderr=subprocess.PIPE,
+                               **kwargs):
        raise NotImplementedError

-    def subprocess_exec(self, protocol_factory, *args, stdin=subprocess.PIPE,
-                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                        **kwargs):
+    async def subprocess_exec(self, protocol_factory, *args,
+                              stdin=subprocess.PIPE,
+                              stdout=subprocess.PIPE,
+                              stderr=subprocess.PIPE,
+                              **kwargs):
        raise NotImplementedError

    # Ready-based callback registration methods.
@@ -463,16 +548,32 @@ class AbstractEventLoop:

    # Completion based I/O methods returning Futures.

-    def sock_recv(self, sock, nbytes):
+    async def sock_recv(self, sock, nbytes):
        raise NotImplementedError

-    def sock_sendall(self, sock, data):
+    async def sock_recv_into(self, sock, buf):
        raise NotImplementedError

-    def sock_connect(self, sock, address):
+    async def sock_recvfrom(self, sock, bufsize):
        raise NotImplementedError

-    def sock_accept(self, sock):
+    async def sock_recvfrom_into(self, sock, buf, nbytes=0):
+        raise NotImplementedError
+
+    async def sock_sendall(self, sock, data):
+        raise NotImplementedError
+
+    async def sock_sendto(self, sock, data, address):
+        raise NotImplementedError
+
+    async def sock_connect(self, sock, address):
+        raise NotImplementedError
+
+    async def sock_accept(self, sock):
+        raise NotImplementedError
+
+    async def sock_sendfile(self, sock, file, offset=0, count=None,
+                            *, fallback=None):
        raise NotImplementedError

    # Signal handling.
@@ -520,7 +621,7 @@ class AbstractEventLoopPolicy:
    def get_event_loop(self):
        """Get the event loop for the current context.

-        Returns an event loop object implementing the BaseEventLoop interface,
+        Returns an event loop object implementing the AbstractEventLoop interface,
        or raises an exception in case no event loop has been set for the
        current context and the current policy does not specify to create one.

@@ -571,23 +672,43 @@ class BaseDefaultEventLoopPolicy(AbstractEventLoopPolicy):
        self._local = self._Local()

    def get_event_loop(self):
-        """Get the event loop.
+        """Get the event loop for the current context.

-        This may be None or an instance of EventLoop.
+        Returns an instance of EventLoop or raises an exception.
        """
        if (self._local._loop is None and
-            not self._local._set_called and
-            isinstance(threading.current_thread(), threading._MainThread)):
+                not self._local._set_called and
+                threading.current_thread() is threading.main_thread()):
+            stacklevel = 2
+            try:
+                f = sys._getframe(1)
+            except AttributeError:
+                pass
+            else:
+                # Move up the call stack so that the warning is attached
+                # to the line outside asyncio itself.
+                while f:
+                    module = f.f_globals.get('__name__')
+                    if not (module == 'asyncio' or module.startswith('asyncio.')):
+                        break
+                    f = f.f_back
+                    stacklevel += 1
+            import warnings
+            warnings.warn('There is no current event loop',
+                          DeprecationWarning, stacklevel=stacklevel)
            self.set_event_loop(self.new_event_loop())
+
        if self._local._loop is None:
            raise RuntimeError('There is no current event loop in thread %r.'
                               % threading.current_thread().name)
+
        return self._local._loop

    def set_event_loop(self, loop):
        """Set the event loop."""
        self._local._set_called = True
-        assert loop is None or isinstance(loop, AbstractEventLoop)
+        if loop is not None and not isinstance(loop, AbstractEventLoop):
+            raise TypeError(f"loop must be an instance of AbstractEventLoop or None, not '{type(loop).__name__}'")
        self._local._loop = loop

    def new_event_loop(self):
@@ -611,7 +732,9 @@ _lock = threading.Lock()

 # A TLS for the running event loop, used by _get_running_loop.
 class _RunningLoop(threading.local):
-    _loop = None
+    loop_pid = (None, None)
+
+
 _running_loop = _RunningLoop()


@@ -633,7 +756,10 @@ def _get_running_loop():
    This is a low-level function intended to be used by event loops.
    This function is thread-specific.
    """
-    return _running_loop._loop
+    # NOTE: this function is implemented in C (see _asynciomodule.c)
+    running_loop, pid = _running_loop.loop_pid
+    if running_loop is not None and pid == os.getpid():
+        return running_loop


 def _set_running_loop(loop):
@@ -642,7 +768,8 @@ def _set_running_loop(loop):
    This is a low-level function intended to be used by event loops.
    This function is thread-specific.
    """
-    _running_loop._loop = loop
+    # NOTE: this function is implemented in C (see _asynciomodule.c)
+    _running_loop.loop_pid = (loop, os.getpid())


 def _init_event_loop_policy():
@@ -665,7 +792,8 @@ def set_event_loop_policy(policy):

    If policy is None, the default policy is restored."""
    global _event_loop_policy
-    assert policy is None or isinstance(policy, AbstractEventLoopPolicy)
+    if policy is not None and not isinstance(policy, AbstractEventLoopPolicy):
+        raise TypeError(f"policy must be an instance of AbstractEventLoopPolicy or None, not '{type(policy).__name__}'")
    _event_loop_policy = policy


@@ -678,6 +806,7 @@ def get_event_loop():
    If there is no running event loop set, the function will return
    the result of `get_event_loop_policy().get_event_loop()` call.
    """
+    # NOTE: this function is implemented in C (see _asynciomodule.c)
    current_loop = _get_running_loop()
    if current_loop is not None:
        return current_loop
@@ -703,3 +832,37 @@ def set_child_watcher(watcher):
    """Equivalent to calling
    get_event_loop_policy().set_child_watcher(watcher)."""
    return get_event_loop_policy().set_child_watcher(watcher)
+
+
+# Alias pure-Python implementations for testing purposes.
+_py__get_running_loop = _get_running_loop
+_py__set_running_loop = _set_running_loop
+_py_get_running_loop = get_running_loop
+_py_get_event_loop = get_event_loop
+
+
+try:
+    # get_event_loop() is one of the most frequently called
+    # functions in asyncio.  Pure Python implementation is
+    # about 4 times slower than C-accelerated.
+    from _asyncio import (_get_running_loop, _set_running_loop,
+                          get_running_loop, get_event_loop)
+except ImportError:
+    pass
+else:
+    # Alias C implementations for testing purposes.
+    _c__get_running_loop = _get_running_loop
+    _c__set_running_loop = _set_running_loop
+    _c_get_running_loop = get_running_loop
+    _c_get_event_loop = get_event_loop
+
+
+if hasattr(os, 'fork'):
+    def on_fork():
+        # Reset the loop and wakeupfd in the forked child process.
+        if _event_loop_policy is not None:
+            _event_loop_policy._local = BaseDefaultEventLoopPolicy._Local()
+        _set_running_loop(None)
+        signal.set_wakeup_fd(-1)
+
+    os.register_at_fork(after_in_child=on_fork)
--- a/Lib/asyncio/exceptions.py
+++ b/Lib/asyncio/exceptions.py
@@ -0,0 +1,62 @@
+"""asyncio exceptions."""
+
+
+__all__ = ('BrokenBarrierError',
+           'CancelledError', 'InvalidStateError', 'TimeoutError',
+           'IncompleteReadError', 'LimitOverrunError',
+           'SendfileNotAvailableError')
+
+
+class CancelledError(BaseException):
+    """The Future or Task was cancelled."""
+
+
+TimeoutError = TimeoutError  # make local alias for the standard exception
+
+
+class InvalidStateError(Exception):
+    """The operation is not allowed in this state."""
+
+
+class SendfileNotAvailableError(RuntimeError):
+    """Sendfile syscall is not available.
+
+    Raised if OS does not support sendfile syscall for given socket or
+    file type.
+    """
+
+
+class IncompleteReadError(EOFError):
+    """
+    Incomplete read error. Attributes:
+
+    - partial: read bytes string before the end of stream was reached
+    - expected: total number of expected bytes (or None if unknown)
+    """
+    def __init__(self, partial, expected):
+        r_expected = 'undefined' if expected is None else repr(expected)
+        super().__init__(f'{len(partial)} bytes read on a total of '
+                         f'{r_expected} expected bytes')
+        self.partial = partial
+        self.expected = expected
+
+    def __reduce__(self):
+        return type(self), (self.partial, self.expected)
+
+
+class LimitOverrunError(Exception):
+    """Reached the buffer limit while looking for a separator.
+
+    Attributes:
+    - consumed: total number of to be consumed bytes.
+    """
+    def __init__(self, message, consumed):
+        super().__init__(message)
+        self.consumed = consumed
+
+    def __reduce__(self):
+        return type(self), (self.args[0], self.consumed)
+
+
+class BrokenBarrierError(RuntimeError):
+    """Barrier is broken by barrier.abort() call."""
--- a/Lib/asyncio/format_helpers.py
+++ b/Lib/asyncio/format_helpers.py
@@ -0,0 +1,76 @@
+import functools
+import inspect
+import reprlib
+import sys
+import traceback
+
+from . import constants
+
+
+def _get_function_source(func):
+    func = inspect.unwrap(func)
+    if inspect.isfunction(func):
+        code = func.__code__
+        return (code.co_filename, code.co_firstlineno)
+    if isinstance(func, functools.partial):
+        return _get_function_source(func.func)
+    if isinstance(func, functools.partialmethod):
+        return _get_function_source(func.func)
+    return None
+
+
+def _format_callback_source(func, args):
+    func_repr = _format_callback(func, args, None)
+    source = _get_function_source(func)
+    if source:
+        func_repr += f' at {source[0]}:{source[1]}'
+    return func_repr
+
+
+def _format_args_and_kwargs(args, kwargs):
+    """Format function arguments and keyword arguments.
+
+    Special case for a single parameter: ('hello',) is formatted as ('hello').
+    """
+    # use reprlib to limit the length of the output
+    items = []
+    if args:
+        items.extend(reprlib.repr(arg) for arg in args)
+    if kwargs:
+        items.extend(f'{k}={reprlib.repr(v)}' for k, v in kwargs.items())
+    return '({})'.format(', '.join(items))
+
+
+def _format_callback(func, args, kwargs, suffix=''):
+    if isinstance(func, functools.partial):
+        suffix = _format_args_and_kwargs(args, kwargs) + suffix
+        return _format_callback(func.func, func.args, func.keywords, suffix)
+
+    if hasattr(func, '__qualname__') and func.__qualname__:
+        func_repr = func.__qualname__
+    elif hasattr(func, '__name__') and func.__name__:
+        func_repr = func.__name__
+    else:
+        func_repr = repr(func)
+
+    func_repr += _format_args_and_kwargs(args, kwargs)
+    if suffix:
+        func_repr += suffix
+    return func_repr
+
+
+def extract_stack(f=None, limit=None):
+    """Replacement for traceback.extract_stack() that only does the
+    necessary work for asyncio debug mode.
+    """
+    if f is None:
+        f = sys._getframe().f_back
+    if limit is None:
+        # Limit the amount of work to a reasonable amount, as extract_stack()
+        # can be called for each coroutine and future in debug mode.
+        limit = constants.DEBUG_STACK_DEPTH
+    stack = traceback.StackSummary.extract(traceback.walk_stack(f),
+                                           limit=limit,
+                                           lookup_lines=False)
+    stack.reverse()
+    return stack
--- a/Lib/asyncio/futures.py
+++ b/Lib/asyncio/futures.py
@@ -1,21 +1,21 @@
 """A Future class similar to the one in PEP 3148."""

-__all__ = ['CancelledError', 'TimeoutError', 'InvalidStateError',
-           'Future', 'wrap_future', 'isfuture']
+__all__ = (
+    'Future', 'wrap_future', 'isfuture',
+)

 import concurrent.futures
+import contextvars
 import logging
 import sys
-import traceback
+from types import GenericAlias

 from . import base_futures
-from . import compat
 from . import events
+from . import exceptions
+from . import format_helpers


-CancelledError = base_futures.CancelledError
-InvalidStateError = base_futures.InvalidStateError
-TimeoutError = base_futures.TimeoutError
 isfuture = base_futures.isfuture


@@ -27,96 +27,18 @@ _FINISHED = base_futures._FINISHED
 STACK_DEBUG = logging.DEBUG - 1  # heavy-duty debugging


-class _TracebackLogger:
-    """Helper to log a traceback upon destruction if not cleared.
-
-    This solves a nasty problem with Futures and Tasks that have an
-    exception set: if nobody asks for the exception, the exception is
-    never logged.  This violates the Zen of Python: 'Errors should
-    never pass silently.  Unless explicitly silenced.'
-
-    However, we don't want to log the exception as soon as
-    set_exception() is called: if the calling code is written
-    properly, it will get the exception and handle it properly.  But
-    we *do* want to log it if result() or exception() was never called
-    -- otherwise developers waste a lot of time wondering why their
-    buggy code fails silently.
-
-    An earlier attempt added a __del__() method to the Future class
-    itself, but this backfired because the presence of __del__()
-    prevents garbage collection from breaking cycles.  A way out of
-    this catch-22 is to avoid having a __del__() method on the Future
-    class itself, but instead to have a reference to a helper object
-    with a __del__() method that logs the traceback, where we ensure
-    that the helper object doesn't participate in cycles, and only the
-    Future has a reference to it.
-
-    The helper object is added when set_exception() is called.  When
-    the Future is collected, and the helper is present, the helper
-    object is also collected, and its __del__() method will log the
-    traceback.  When the Future's result() or exception() method is
-    called (and a helper object is present), it removes the helper
-    object, after calling its clear() method to prevent it from
-    logging.
-
-    One downside is that we do a fair amount of work to extract the
-    traceback from the exception, even when it is never logged.  It
-    would seem cheaper to just store the exception object, but that
-    references the traceback, which references stack frames, which may
-    reference the Future, which references the _TracebackLogger, and
-    then the _TracebackLogger would be included in a cycle, which is
-    what we're trying to avoid!  As an optimization, we don't
-    immediately format the exception; we only do the work when
-    activate() is called, which call is delayed until after all the
-    Future's callbacks have run.  Since usually a Future has at least
-    one callback (typically set by 'yield from') and usually that
-    callback extracts the callback, thereby removing the need to
-    format the exception.
-
-    PS. I don't claim credit for this solution.  I first heard of it
-    in a discussion about closing files when they are collected.
-    """
-
-    __slots__ = ('loop', 'source_traceback', 'exc', 'tb')
-
-    def __init__(self, future, exc):
-        self.loop = future._loop
-        self.source_traceback = future._source_traceback
-        self.exc = exc
-        self.tb = None
-
-    def activate(self):
-        exc = self.exc
-        if exc is not None:
-            self.exc = None
-            self.tb = traceback.format_exception(exc.__class__, exc,
-                                                 exc.__traceback__)
-
-    def clear(self):
-        self.exc = None
-        self.tb = None
-
-    def __del__(self):
-        if self.tb:
-            msg = 'Future/Task exception was never retrieved\n'
-            if self.source_traceback:
-                src = ''.join(traceback.format_list(self.source_traceback))
-                msg += 'Future/Task created at (most recent call last):\n'
-                msg += '%s\n' % src.rstrip()
-            msg += ''.join(self.tb).rstrip()
-            self.loop.call_exception_handler({'message': msg})
-
-
 class Future:
    """This class is *almost* compatible with concurrent.futures.Future.

    Differences:

+    - This class is not thread-safe.
+
    - result() and exception() do not take a timeout argument and
      raise an exception when the future isn't done yet.

    - Callbacks registered with add_done_callback() are always called
-      via the event loop's call_soon_threadsafe().
+      via the event loop's call_soon().

    - This class is not compatible with the wait() and as_completed()
      methods in the concurrent.futures package.
@@ -130,6 +52,9 @@ class Future:
    _exception = None
    _loop = None
    _source_traceback = None
+    _cancel_message = None
+    # A saved CancelledError for later chaining as an exception context.
+    _cancelled_exc = None

    # This field is used for a dual purpose:
    # - Its presence is a marker to declare that a class implements
@@ -137,12 +62,12 @@ class Future:
    #   The value must also be not-None, to enable a subclass to declare
    #   that it is not compatible by setting this to None.
    # - It is set by __iter__() below so that Task._step() can tell
-    #   the difference between `yield from Future()` (correct) vs.
+    #   the difference between
+    #   `await Future()` or`yield from Future()` (correct) vs.
    #   `yield Future()` (incorrect).
    _asyncio_future_blocking = False

-    _log_traceback = False   # Used for Python 3.4 and later
-    _tb_logger = None        # Used for Python 3.3 only
+    __log_traceback = False

    def __init__(self, *, loop=None):
        """Initialize the future.
@@ -157,50 +82,83 @@ class Future:
            self._loop = loop
        self._callbacks = []
        if self._loop.get_debug():
-            self._source_traceback = traceback.extract_stack(sys._getframe(1))
-
-    _repr_info = base_futures._future_repr_info
+            self._source_traceback = format_helpers.extract_stack(
+                sys._getframe(1))

    def __repr__(self):
-        return '<%s %s>' % (self.__class__.__name__, ' '.join(self._repr_info()))
+        return base_futures._future_repr(self)

-    # On Python 3.3 and older, objects with a destructor part of a reference
-    # cycle are never destroyed. It's not more the case on Python 3.4 thanks
-    # to the PEP 442.
-    if compat.PY34:
-        def __del__(self):
-            if not self._log_traceback:
-                # set_exception() was not called, or result() or exception()
-                # has consumed the exception
-                return
-            exc = self._exception
-            context = {
-                'message': ('%s exception was never retrieved'
-                            % self.__class__.__name__),
-                'exception': exc,
-                'future': self,
-            }
-            if self._source_traceback:
-                context['source_traceback'] = self._source_traceback
-            self._loop.call_exception_handler(context)
+    def __del__(self):
+        if not self.__log_traceback:
+            # set_exception() was not called, or result() or exception()
+            # has consumed the exception
+            return
+        exc = self._exception
+        context = {
+            'message':
+                f'{self.__class__.__name__} exception was never retrieved',
+            'exception': exc,
+            'future': self,
+        }
+        if self._source_traceback:
+            context['source_traceback'] = self._source_traceback
+        self._loop.call_exception_handler(context)

-    def __class_getitem__(cls, type):
-        return cls
+    __class_getitem__ = classmethod(GenericAlias)

-    def cancel(self):
+    @property
+    def _log_traceback(self):
+        return self.__log_traceback
+
+    @_log_traceback.setter
+    def _log_traceback(self, val):
+        if val:
+            raise ValueError('_log_traceback can only be set to False')
+        self.__log_traceback = False
+
+    def get_loop(self):
+        """Return the event loop the Future is bound to."""
+        loop = self._loop
+        if loop is None:
+            raise RuntimeError("Future object is not initialized.")
+        return loop
+
+    def _make_cancelled_error(self):
+        """Create the CancelledError to raise if the Future is cancelled.
+
+        This should only be called once when handling a cancellation since
+        it erases the saved context exception value.
+        """
+        if self._cancelled_exc is not None:
+            exc = self._cancelled_exc
+            self._cancelled_exc = None
+            return exc
+
+        if self._cancel_message is None:
+            exc = exceptions.CancelledError()
+        else:
+            exc = exceptions.CancelledError(self._cancel_message)
+        exc.__context__ = self._cancelled_exc
+        # Remove the reference since we don't need this anymore.
+        self._cancelled_exc = None
+        return exc
+
+    def cancel(self, msg=None):
        """Cancel the future and schedule callbacks.

        If the future is already done or cancelled, return False.  Otherwise,
        change the future's state to cancelled, schedule the callbacks and
        return True.
        """
+        self.__log_traceback = False
        if self._state != _PENDING:
            return False
        self._state = _CANCELLED
-        self._schedule_callbacks()
+        self._cancel_message = msg
+        self.__schedule_callbacks()
        return True

-    def _schedule_callbacks(self):
+    def __schedule_callbacks(self):
        """Internal: Ask the event loop to call all callbacks.

        The callbacks are scheduled to be called as soon as possible. Also
@@ -211,8 +169,8 @@ class Future:
            return

        self._callbacks[:] = []
-        for callback in callbacks:
-            self._loop.call_soon(callback, self)
+        for callback, ctx in callbacks:
+            self._loop.call_soon(callback, self, context=ctx)

    def cancelled(self):
        """Return True if the future was cancelled."""
@@ -236,15 +194,13 @@ class Future:
        the future is done and has an exception set, this exception is raised.
        """
        if self._state == _CANCELLED:
-            raise CancelledError
+            exc = self._make_cancelled_error()
+            raise exc
        if self._state != _FINISHED:
-            raise InvalidStateError('Result is not ready.')
-        self._log_traceback = False
-        if self._tb_logger is not None:
-            self._tb_logger.clear()
-            self._tb_logger = None
+            raise exceptions.InvalidStateError('Result is not ready.')
+        self.__log_traceback = False
        if self._exception is not None:
-            raise self._exception
+            raise self._exception.with_traceback(self._exception_tb)
        return self._result

    def exception(self):
@@ -256,16 +212,14 @@ class Future:
        InvalidStateError.
        """
        if self._state == _CANCELLED:
-            raise CancelledError
+            exc = self._make_cancelled_error()
+            raise exc
        if self._state != _FINISHED:
-            raise InvalidStateError('Exception is not set.')
-        self._log_traceback = False
-        if self._tb_logger is not None:
-            self._tb_logger.clear()
-            self._tb_logger = None
+            raise exceptions.InvalidStateError('Exception is not set.')
+        self.__log_traceback = False
        return self._exception

-    def add_done_callback(self, fn):
+    def add_done_callback(self, fn, *, context=None):
        """Add a callback to be run when the future becomes done.

        The callback is called with a single argument - the future object. If
@@ -273,9 +227,11 @@ class Future:
        scheduled with call_soon.
        """
        if self._state != _PENDING:
-            self._loop.call_soon(fn, self)
+            self._loop.call_soon(fn, self, context=context)
        else:
-            self._callbacks.append(fn)
+            if context is None:
+                context = contextvars.copy_context()
+            self._callbacks.append((fn, context))

    # New method not in PEP 3148.

@@ -284,7 +240,9 @@ class Future:

        Returns the number of callbacks removed.
        """
-        filtered_callbacks = [f for f in self._callbacks if f != fn]
+        filtered_callbacks = [(f, ctx)
+                              for (f, ctx) in self._callbacks
+                              if f != fn]
        removed_count = len(self._callbacks) - len(filtered_callbacks)
        if removed_count:
            self._callbacks[:] = filtered_callbacks
@@ -299,10 +257,10 @@ class Future:
        InvalidStateError.
        """
        if self._state != _PENDING:
-            raise InvalidStateError('{}: {!r}'.format(self._state, self))
+            raise exceptions.InvalidStateError(f'{self._state}: {self!r}')
        self._result = result
        self._state = _FINISHED
-        self._schedule_callbacks()
+        self.__schedule_callbacks()

    def set_exception(self, exception):
        """Mark the future done and set an exception.
@@ -311,38 +269,45 @@ class Future:
        InvalidStateError.
        """
        if self._state != _PENDING:
-            raise InvalidStateError('{}: {!r}'.format(self._state, self))
+            raise exceptions.InvalidStateError(f'{self._state}: {self!r}')
        if isinstance(exception, type):
            exception = exception()
        if type(exception) is StopIteration:
            raise TypeError("StopIteration interacts badly with generators "
                            "and cannot be raised into a Future")
        self._exception = exception
+        self._exception_tb = exception.__traceback__
        self._state = _FINISHED
-        self._schedule_callbacks()
-        if compat.PY34:
-            self._log_traceback = True
-        else:
-            self._tb_logger = _TracebackLogger(self, exception)
-            # Arrange for the logger to be activated after all callbacks
-            # have had a chance to call result() or exception().
-            self._loop.call_soon(self._tb_logger.activate)
+        self.__schedule_callbacks()
+        self.__log_traceback = True

-    def __iter__(self):
+    def __await__(self):
        if not self.done():
            self._asyncio_future_blocking = True
            yield self  # This tells Task to wait for completion.
-        assert self.done(), "yield from wasn't used with future"
+        if not self.done():
+            raise RuntimeError("await wasn't used with future")
        return self.result()  # May raise too.

-    if compat.PY35:
-        __await__ = __iter__ # make compatible with 'await' expression
+    __iter__ = __await__  # make compatible with 'yield from'.


 # Needed for testing purposes.
 _PyFuture = Future


+def _get_loop(fut):
+    # Tries to call Future.get_loop() if it's available.
+    # Otherwise fallbacks to using the old '_loop' property.
+    try:
+        get_loop = fut.get_loop
+    except AttributeError:
+        pass
+    else:
+        return get_loop()
+    return fut._loop
+
+
 def _set_result_unless_cancelled(fut, result):
    """Helper setting the result only if the future was not cancelled."""
    if fut.cancelled():
@@ -350,6 +315,18 @@ def _set_result_unless_cancelled(fut, result):
    fut.set_result(result)


+def _convert_future_exc(exc):
+    exc_class = type(exc)
+    if exc_class is concurrent.futures.CancelledError:
+        return exceptions.CancelledError(*exc.args)
+    elif exc_class is concurrent.futures.TimeoutError:
+        return exceptions.TimeoutError(*exc.args)
+    elif exc_class is concurrent.futures.InvalidStateError:
+        return exceptions.InvalidStateError(*exc.args)
+    else:
+        return exc
+
+
 def _set_concurrent_future_state(concurrent, source):
    """Copy state from a future to a concurrent.futures.Future."""
    assert source.done()
@@ -359,7 +336,7 @@ def _set_concurrent_future_state(concurrent, source):
        return
    exception = source.exception()
    if exception is not None:
-        concurrent.set_exception(exception)
+        concurrent.set_exception(_convert_future_exc(exception))
    else:
        result = source.result()
        concurrent.set_result(result)
@@ -379,7 +356,7 @@ def _copy_future_state(source, dest):
    else:
        exception = source.exception()
        if exception is not None:
-            dest.set_exception(exception)
+            dest.set_exception(_convert_future_exc(exception))
        else:
            result = source.result()
            dest.set_result(result)
@@ -398,8 +375,8 @@ def _chain_future(source, destination):
    if not isfuture(destination) and not isinstance(destination,
                                                    concurrent.futures.Future):
        raise TypeError('A future is required for destination argument')
-    source_loop = source._loop if isfuture(source) else None
-    dest_loop = destination._loop if isfuture(destination) else None
+    source_loop = _get_loop(source) if isfuture(source) else None
+    dest_loop = _get_loop(destination) if isfuture(destination) else None

    def _set_state(future, other):
        if isfuture(future):
@@ -415,9 +392,14 @@ def _chain_future(source, destination):
                source_loop.call_soon_threadsafe(source.cancel)

    def _call_set_state(source):
+        if (destination.cancelled() and
+                dest_loop is not None and dest_loop.is_closed()):
+            return
        if dest_loop is None or dest_loop is source_loop:
            _set_state(destination, source)
        else:
+            if dest_loop.is_closed():
+                return
            dest_loop.call_soon_threadsafe(_set_state, destination, source)

    destination.add_done_callback(_call_check_cancel)
@@ -429,7 +411,7 @@ def wrap_future(future, *, loop=None):
    if isfuture(future):
        return future
    assert isinstance(future, concurrent.futures.Future), \
-        'concurrent.futures.Future is expected, got {!r}'.format(future)
+        f'concurrent.futures.Future is expected, got {future!r}'
    if loop is None:
        loop = events.get_event_loop()
    new_future = loop.create_future()
--- a/Lib/asyncio/locks.py
+++ b/Lib/asyncio/locks.py
@@ -1,92 +1,26 @@
 """Synchronization primitives."""

-__all__ = ['Lock', 'Event', 'Condition', 'Semaphore', 'BoundedSemaphore']
+__all__ = ('Lock', 'Event', 'Condition', 'Semaphore',
+           'BoundedSemaphore', 'Barrier')

 import collections
+import enum

-from . import compat
-from . import events
-from . import futures
-from .coroutines import coroutine
+from . import exceptions
+from . import mixins

-
-class _ContextManager:
-    """Context manager.
-
-    This enables the following idiom for acquiring and releasing a
-    lock around a block:
-
-        with (yield from lock):
-            <block>
-
-    while failing loudly when accidentally using:
-
-        with lock:
-            <block>
-    """
-
-    def __init__(self, lock):
-        self._lock = lock
-
-    def __enter__(self):
+class _ContextManagerMixin:
+    async def __aenter__(self):
+        await self.acquire()
        # We have no use for the "as ..."  clause in the with
        # statement for locks.
        return None

-    def __exit__(self, *args):
-        try:
-            self._lock.release()
-        finally:
-            self._lock = None  # Crudely prevent reuse.
+    async def __aexit__(self, exc_type, exc, tb):
+        self.release()


-class _ContextManagerMixin:
-    def __enter__(self):
-        raise RuntimeError(
-            '"yield from" should be used as context manager expression')
-
-    def __exit__(self, *args):
-        # This must exist because __enter__ exists, even though that
-        # always raises; that's how the with-statement works.
-        pass
-
-    @coroutine
-    def __iter__(self):
-        # This is not a coroutine.  It is meant to enable the idiom:
-        #
-        #     with (yield from lock):
-        #         <block>
-        #
-        # as an alternative to:
-        #
-        #     yield from lock.acquire()
-        #     try:
-        #         <block>
-        #     finally:
-        #         lock.release()
-        yield from self.acquire()
-        return _ContextManager(self)
-
-    if compat.PY35:
-
-        def __await__(self):
-            # To make "with await lock" work.
-            yield from self.acquire()
-            return _ContextManager(self)
-
-        @coroutine
-        def __aenter__(self):
-            yield from self.acquire()
-            # We have no use for the "as ..."  clause in the with
-            # statement for locks.
-            return None
-
-        @coroutine
-        def __aexit__(self, exc_type, exc, tb):
-            self.release()
-
-
-class Lock(_ContextManagerMixin):
+class Lock(_ContextManagerMixin, mixins._LoopBoundMixin):
    """Primitive lock objects.

    A primitive lock is a synchronization primitive that is not owned
@@ -108,16 +42,16 @@ class Lock(_ContextManagerMixin):
    release() call resets the state to unlocked; first coroutine which
    is blocked in acquire() is being processed.

-    acquire() is a coroutine and should be called with 'yield from'.
+    acquire() is a coroutine and should be called with 'await'.

-    Locks also support the context management protocol.  '(yield from lock)'
-    should be used as the context manager expression.
+    Locks also support the asynchronous context management protocol.
+    'async with lock' statement should be used.

    Usage:

        lock = Lock()
        ...
-        yield from lock
+        await lock.acquire()
        try:
            ...
        finally:
@@ -127,57 +61,65 @@ class Lock(_ContextManagerMixin):

        lock = Lock()
        ...
-        with (yield from lock):
+        async with lock:
             ...

    Lock objects can be tested for locking state:

        if not lock.locked():
-           yield from lock
+           await lock.acquire()
        else:
           # lock is acquired
           ...

    """

-    def __init__(self, *, loop=None):
-        self._waiters = collections.deque()
+    def __init__(self):
+        self._waiters = None
        self._locked = False
-        if loop is not None:
-            self._loop = loop
-        else:
-            self._loop = events.get_event_loop()

    def __repr__(self):
        res = super().__repr__()
        extra = 'locked' if self._locked else 'unlocked'
        if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'

    def locked(self):
        """Return True if lock is acquired."""
        return self._locked

-    @coroutine
-    def acquire(self):
+    async def acquire(self):
        """Acquire a lock.

        This method blocks until the lock is unlocked, then sets it to
        locked and returns True.
        """
-        if not self._locked and all(w.cancelled() for w in self._waiters):
+        if (not self._locked and (self._waiters is None or
+                all(w.cancelled() for w in self._waiters))):
            self._locked = True
            return True

-        fut = self._loop.create_future()
+        if self._waiters is None:
+            self._waiters = collections.deque()
+        fut = self._get_loop().create_future()
        self._waiters.append(fut)
+
+        # Finally block should be called before the CancelledError
+        # handling as we don't want CancelledError to call
+        # _wake_up_first() and attempt to wake up itself.
        try:
-            yield from fut
-            self._locked = True
-            return True
-        finally:
-            self._waiters.remove(fut)
+            try:
+                await fut
+            finally:
+                self._waiters.remove(fut)
+        except exceptions.CancelledError:
+            if not self._locked:
+                self._wake_up_first()
+            raise
+
+        self._locked = True
+        return True

    def release(self):
        """Release a lock.
@@ -192,16 +134,27 @@ class Lock(_ContextManagerMixin):
        """
        if self._locked:
            self._locked = False
-            # Wake up the first waiter who isn't cancelled.
-            for fut in self._waiters:
-                if not fut.done():
-                    fut.set_result(True)
-                    break
+            self._wake_up_first()
        else:
            raise RuntimeError('Lock is not acquired.')

+    def _wake_up_first(self):
+        """Wake up the first waiter if it isn't done."""
+        if not self._waiters:
+            return
+        try:
+            fut = next(iter(self._waiters))
+        except StopIteration:
+            return

-class Event:
+        # .done() necessarily means that a waiter will wake up later on and
+        # either take the lock, or, if it was cancelled and lock wasn't
+        # taken already, will hit this again and wake up a new waiter.
+        if not fut.done():
+            fut.set_result(True)
+
+
+class Event(mixins._LoopBoundMixin):
    """Asynchronous equivalent to threading.Event.

    Class implementing event objects. An event manages a flag that can be set
@@ -210,20 +163,16 @@ class Event:
    false.
    """

-    def __init__(self, *, loop=None):
+    def __init__(self):
        self._waiters = collections.deque()
        self._value = False
-        if loop is not None:
-            self._loop = loop
-        else:
-            self._loop = events.get_event_loop()

    def __repr__(self):
        res = super().__repr__()
        extra = 'set' if self._value else 'unset'
        if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'

    def is_set(self):
        """Return True if and only if the internal flag is true."""
@@ -247,8 +196,7 @@ class Event:
        to true again."""
        self._value = False

-    @coroutine
-    def wait(self):
+    async def wait(self):
        """Block until the internal flag is true.

        If the internal flag is true on entry, return True
@@ -258,16 +206,16 @@ class Event:
        if self._value:
            return True

-        fut = self._loop.create_future()
+        fut = self._get_loop().create_future()
        self._waiters.append(fut)
        try:
-            yield from fut
+            await fut
            return True
        finally:
            self._waiters.remove(fut)


-class Condition(_ContextManagerMixin):
+class Condition(_ContextManagerMixin, mixins._LoopBoundMixin):
    """Asynchronous equivalent to threading.Condition.

    This class implements condition variable objects. A condition variable
@@ -277,16 +225,9 @@ class Condition(_ContextManagerMixin):
    A new Lock object is created and used as the underlying lock.
    """

-    def __init__(self, lock=None, *, loop=None):
-        if loop is not None:
-            self._loop = loop
-        else:
-            self._loop = events.get_event_loop()
-
+    def __init__(self, lock=None):
        if lock is None:
-            lock = Lock(loop=self._loop)
-        elif lock._loop is not self._loop:
-            raise ValueError("loop argument must agree with lock")
+            lock = Lock()

        self._lock = lock
        # Export the lock's locked(), acquire() and release() methods.
@@ -300,11 +241,10 @@ class Condition(_ContextManagerMixin):
        res = super().__repr__()
        extra = 'locked' if self.locked() else 'unlocked'
        if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'

-    @coroutine
-    def wait(self):
+    async def wait(self):
        """Wait until notified.

        If the calling coroutine has not acquired the lock when this
@@ -320,25 +260,28 @@ class Condition(_ContextManagerMixin):

        self.release()
        try:
-            fut = self._loop.create_future()
+            fut = self._get_loop().create_future()
            self._waiters.append(fut)
            try:
-                yield from fut
+                await fut
                return True
            finally:
                self._waiters.remove(fut)

        finally:
            # Must reacquire lock even if wait is cancelled
+            cancelled = False
            while True:
                try:
-                    yield from self.acquire()
+                    await self.acquire()
                    break
-                except futures.CancelledError:
-                    pass
+                except exceptions.CancelledError:
+                    cancelled = True

-    @coroutine
-    def wait_for(self, predicate):
+            if cancelled:
+                raise exceptions.CancelledError
+
+    async def wait_for(self, predicate):
        """Wait until a predicate becomes true.

        The predicate should be a callable which result will be
@@ -347,7 +290,7 @@ class Condition(_ContextManagerMixin):
        """
        result = predicate()
        while not result:
-            yield from self.wait()
+            await self.wait()
            result = predicate()
        return result

@@ -384,7 +327,7 @@ class Condition(_ContextManagerMixin):
        self.notify(len(self._waiters))


-class Semaphore(_ContextManagerMixin):
+class Semaphore(_ContextManagerMixin, mixins._LoopBoundMixin):
    """A Semaphore implementation.

    A semaphore manages an internal counter which is decremented by each
@@ -399,37 +342,25 @@ class Semaphore(_ContextManagerMixin):
    ValueError is raised.
    """

-    def __init__(self, value=1, *, loop=None):
+    def __init__(self, value=1):
        if value < 0:
            raise ValueError("Semaphore initial value must be >= 0")
+        self._waiters = None
        self._value = value
-        self._waiters = collections.deque()
-        if loop is not None:
-            self._loop = loop
-        else:
-            self._loop = events.get_event_loop()

    def __repr__(self):
        res = super().__repr__()
-        extra = 'locked' if self.locked() else 'unlocked,value:{}'.format(
-            self._value)
+        extra = 'locked' if self.locked() else f'unlocked, value:{self._value}'
        if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
-
-    def _wake_up_next(self):
-        while self._waiters:
-            waiter = self._waiters.popleft()
-            if not waiter.done():
-                waiter.set_result(None)
-                return
+            extra = f'{extra}, waiters:{len(self._waiters)}'
+        return f'<{res[1:-1]} [{extra}]>'

    def locked(self):
-        """Returns True if semaphore can not be acquired immediately."""
-        return self._value == 0
+        """Returns True if semaphore cannot be acquired immediately."""
+        return self._value == 0 or (
+            any(not w.cancelled() for w in (self._waiters or ())))

-    @coroutine
-    def acquire(self):
+    async def acquire(self):
        """Acquire a semaphore.

        If the internal counter is larger than zero on entry,
@@ -438,28 +369,53 @@ class Semaphore(_ContextManagerMixin):
        called release() to make it larger than 0, and then return
        True.
        """
-        while self._value <= 0:
-            fut = self._loop.create_future()
-            self._waiters.append(fut)
+        if not self.locked():
+            self._value -= 1
+            return True
+
+        if self._waiters is None:
+            self._waiters = collections.deque()
+        fut = self._get_loop().create_future()
+        self._waiters.append(fut)
+
+        # Finally block should be called before the CancelledError
+        # handling as we don't want CancelledError to call
+        # _wake_up_first() and attempt to wake up itself.
+        try:
            try:
-                yield from fut
-            except:
-                # See the similar code in Queue.get.
-                fut.cancel()
-                if self._value > 0 and not fut.cancelled():
-                    self._wake_up_next()
-                raise
-        self._value -= 1
+                await fut
+            finally:
+                self._waiters.remove(fut)
+        except exceptions.CancelledError:
+            if not fut.cancelled():
+                self._value += 1
+                self._wake_up_next()
+            raise
+
+        if self._value > 0:
+            self._wake_up_next()
        return True

    def release(self):
        """Release a semaphore, incrementing the internal counter by one.
+
        When it was zero on entry and another coroutine is waiting for it to
        become larger than zero again, wake up that coroutine.
        """
        self._value += 1
        self._wake_up_next()

+    def _wake_up_next(self):
+        """Wake up the first waiter that isn't done."""
+        if not self._waiters:
+            return
+
+        for fut in self._waiters:
+            if not fut.done():
+                self._value -= 1
+                fut.set_result(True)
+                return
+

 class BoundedSemaphore(Semaphore):
    """A bounded semaphore implementation.
@@ -468,11 +424,163 @@ class BoundedSemaphore(Semaphore):
    above the initial value.
    """

-    def __init__(self, value=1, *, loop=None):
+    def __init__(self, value=1):
        self._bound_value = value
-        super().__init__(value, loop=loop)
+        super().__init__(value)

    def release(self):
        if self._value >= self._bound_value:
            raise ValueError('BoundedSemaphore released too many times')
        super().release()
+
+
+
+class _BarrierState(enum.Enum):
+    FILLING = 'filling'
+    DRAINING = 'draining'
+    RESETTING = 'resetting'
+    BROKEN = 'broken'
+
+
+class Barrier(mixins._LoopBoundMixin):
+    """Asyncio equivalent to threading.Barrier
+
+    Implements a Barrier primitive.
+    Useful for synchronizing a fixed number of tasks at known synchronization
+    points. Tasks block on 'wait()' and are simultaneously awoken once they
+    have all made their call.
+    """
+
+    def __init__(self, parties):
+        """Create a barrier, initialised to 'parties' tasks."""
+        if parties < 1:
+            raise ValueError('parties must be > 0')
+
+        self._cond = Condition() # notify all tasks when state changes
+
+        self._parties = parties
+        self._state = _BarrierState.FILLING
+        self._count = 0       # count tasks in Barrier
+
+    def __repr__(self):
+        res = super().__repr__()
+        extra = f'{self._state.value}'
+        if not self.broken:
+            extra += f', waiters:{self.n_waiting}/{self.parties}'
+        return f'<{res[1:-1]} [{extra}]>'
+
+    async def __aenter__(self):
+        # wait for the barrier reaches the parties number
+        # when start draining release and return index of waited task
+        return await self.wait()
+
+    async def __aexit__(self, *args):
+        pass
+
+    async def wait(self):
+        """Wait for the barrier.
+
+        When the specified number of tasks have started waiting, they are all
+        simultaneously awoken.
+        Returns an unique and individual index number from 0 to 'parties-1'.
+        """
+        async with self._cond:
+            await self._block() # Block while the barrier drains or resets.
+            try:
+                index = self._count
+                self._count += 1
+                if index + 1 == self._parties:
+                    # We release the barrier
+                    await self._release()
+                else:
+                    await self._wait()
+                return index
+            finally:
+                self._count -= 1
+                # Wake up any tasks waiting for barrier to drain.
+                self._exit()
+
+    async def _block(self):
+        # Block until the barrier is ready for us,
+        # or raise an exception if it is broken.
+        #
+        # It is draining or resetting, wait until done
+        # unless a CancelledError occurs
+        await self._cond.wait_for(
+            lambda: self._state not in (
+                _BarrierState.DRAINING, _BarrierState.RESETTING
+            )
+        )
+
+        # see if the barrier is in a broken state
+        if self._state is _BarrierState.BROKEN:
+            raise exceptions.BrokenBarrierError("Barrier aborted")
+
+    async def _release(self):
+        # Release the tasks waiting in the barrier.
+
+        # Enter draining state.
+        # Next waiting tasks will be blocked until the end of draining.
+        self._state = _BarrierState.DRAINING
+        self._cond.notify_all()
+
+    async def _wait(self):
+        # Wait in the barrier until we are released. Raise an exception
+        # if the barrier is reset or broken.
+
+        # wait for end of filling
+        # unless a CancelledError occurs
+        await self._cond.wait_for(lambda: self._state is not _BarrierState.FILLING)
+
+        if self._state in (_BarrierState.BROKEN, _BarrierState.RESETTING):
+            raise exceptions.BrokenBarrierError("Abort or reset of barrier")
+
+    def _exit(self):
+        # If we are the last tasks to exit the barrier, signal any tasks
+        # waiting for the barrier to drain.
+        if self._count == 0:
+            if self._state in (_BarrierState.RESETTING, _BarrierState.DRAINING):
+                self._state = _BarrierState.FILLING
+            self._cond.notify_all()
+
+    async def reset(self):
+        """Reset the barrier to the initial state.
+
+        Any tasks currently waiting will get the BrokenBarrier exception
+        raised.
+        """
+        async with self._cond:
+            if self._count > 0:
+                if self._state is not _BarrierState.RESETTING:
+                    #reset the barrier, waking up tasks
+                    self._state = _BarrierState.RESETTING
+            else:
+                self._state = _BarrierState.FILLING
+            self._cond.notify_all()
+
+    async def abort(self):
+        """Place the barrier into a 'broken' state.
+
+        Useful in case of error.  Any currently waiting tasks and tasks
+        attempting to 'wait()' will have BrokenBarrierError raised.
+        """
+        async with self._cond:
+            self._state = _BarrierState.BROKEN
+            self._cond.notify_all()
+
+    @property
+    def parties(self):
+        """Return the number of tasks required to trip the barrier."""
+        return self._parties
+
+    @property
+    def n_waiting(self):
+        """Return the number of tasks currently waiting at the barrier."""
+        if self._state is _BarrierState.FILLING:
+            return self._count
+        return 0
+
+    @property
+    def broken(self):
+        """Return True if the barrier is in a broken state."""
+        return self._state is _BarrierState.BROKEN
--- a/Lib/asyncio/mixins.py
+++ b/Lib/asyncio/mixins.py
@@ -0,0 +1,21 @@
+"""Event loop mixins."""
+
+import threading
+from . import events
+
+_global_lock = threading.Lock()
+
+
+class _LoopBoundMixin:
+    _loop = None
+
+    def _get_loop(self):
+        loop = events._get_running_loop()
+
+        if self._loop is None:
+            with _global_lock:
+                if self._loop is None:
+                    self._loop = loop
+        if loop is not self._loop:
+            raise RuntimeError(f'{self!r} is bound to a different event loop')
+        return loop
--- a/Lib/asyncio/proactor_events.py
+++ b/Lib/asyncio/proactor_events.py
@@ -4,20 +4,45 @@ A proactor is a "notify-on-completion" multiplexer.  Currently a
 proactor is only implemented on Windows with IOCP.
 """

-__all__ = ['BaseProactorEventLoop']
+__all__ = 'BaseProactorEventLoop',

+import io
+import os
 import socket
 import warnings
+import signal
+import threading
+import collections

 from . import base_events
-from . import compat
 from . import constants
 from . import futures
+from . import exceptions
+from . import protocols
 from . import sslproto
 from . import transports
+from . import trsock
 from .log import logger


+def _set_socket_extra(transport, sock):
+    transport._extra['socket'] = trsock.TransportSocket(sock)
+
+    try:
+        transport._extra['sockname'] = sock.getsockname()
+    except socket.error:
+        if transport._loop.get_debug():
+            logger.warning(
+                "getsockname() failed on %r", sock, exc_info=True)
+
+    if 'peername' not in transport._extra:
+        try:
+            transport._extra['peername'] = sock.getpeername()
+        except socket.error:
+            # UDP sockets may not have a peer name
+            transport._extra['peername'] = None
+
+
 class _ProactorBasePipeTransport(transports._FlowControlMixin,
                                 transports.BaseTransport):
    """Base class for pipe and socket transports."""
@@ -27,7 +52,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
        super().__init__(extra, loop)
        self._set_extra(sock)
        self._sock = sock
-        self._protocol = protocol
+        self.set_protocol(protocol)
        self._server = server
        self._buffer = None  # None or bytearray.
        self._read_fut = None
@@ -35,6 +60,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
        self._pending_write = 0
        self._conn_lost = 0
        self._closing = False  # Set when close() called.
+        self._called_connection_lost = False
        self._eof_written = False
        if self._server is not None:
            self._server._attach()
@@ -51,17 +77,16 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
        elif self._closing:
            info.append('closing')
        if self._sock is not None:
-            info.append('fd=%s' % self._sock.fileno())
+            info.append(f'fd={self._sock.fileno()}')
        if self._read_fut is not None:
-            info.append('read=%s' % self._read_fut)
+            info.append(f'read={self._read_fut!r}')
        if self._write_fut is not None:
-            info.append("write=%r" % self._write_fut)
+            info.append(f'write={self._write_fut!r}')
        if self._buffer:
-            bufsize = len(self._buffer)
-            info.append('write_bufsize=%s' % bufsize)
+            info.append(f'write_bufsize={len(self._buffer)}')
        if self._eof_written:
            info.append('EOF written')
-        return '<%s>' % ' '.join(info)
+        return '<{}>'.format(' '.join(info))

    def _set_extra(self, sock):
        self._extra['pipe'] = sock
@@ -86,31 +111,33 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
            self._read_fut.cancel()
            self._read_fut = None

-    # On Python 3.3 and older, objects with a destructor part of a reference
-    # cycle are never destroyed. It's not more the case on Python 3.4 thanks
-    # to the PEP 442.
-    if compat.PY34:
-        def __del__(self):
-            if self._sock is not None:
-                warnings.warn("unclosed transport %r" % self, ResourceWarning,
-                              source=self)
-                self.close()
+    def __del__(self, _warn=warnings.warn):
+        if self._sock is not None:
+            _warn(f"unclosed transport {self!r}", ResourceWarning, source=self)
+            self._sock.close()

    def _fatal_error(self, exc, message='Fatal error on pipe transport'):
-        if isinstance(exc, base_events._FATAL_ERROR_IGNORE):
-            if self._loop.get_debug():
-                logger.debug("%r: %s", self, message, exc_info=True)
-        else:
-            self._loop.call_exception_handler({
-                'message': message,
-                'exception': exc,
-                'transport': self,
-                'protocol': self._protocol,
-            })
-        self._force_close(exc)
+        try:
+            if isinstance(exc, OSError):
+                if self._loop.get_debug():
+                    logger.debug("%r: %s", self, message, exc_info=True)
+            else:
+                self._loop.call_exception_handler({
+                    'message': message,
+                    'exception': exc,
+                    'transport': self,
+                    'protocol': self._protocol,
+                })
+        finally:
+            self._force_close(exc)

    def _force_close(self, exc):
-        if self._closing:
+        if self._empty_waiter is not None and not self._empty_waiter.done():
+            if exc is None:
+                self._empty_waiter.set_result(None)
+            else:
+                self._empty_waiter.set_exception(exc)
+        if self._closing and self._called_connection_lost:
            return
        self._closing = True
        self._conn_lost += 1
@@ -125,6 +152,8 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
        self._loop.call_soon(self._call_connection_lost, exc)

    def _call_connection_lost(self, exc):
+        if self._called_connection_lost:
+            return
        try:
            self._protocol.connection_lost(exc)
        finally:
@@ -132,7 +161,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
            # end then it may fail with ERROR_NETNAME_DELETED if we
            # just close our end.  First calling shutdown() seems to
            # cure it, but maybe using DisconnectEx() would be better.
-            if hasattr(self._sock, 'shutdown'):
+            if hasattr(self._sock, 'shutdown') and self._sock.fileno() != -1:
                self._sock.shutdown(socket.SHUT_RDWR)
            self._sock.close()
            self._sock = None
@@ -140,6 +169,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
            if server is not None:
                server._detach()
                self._server = None
+            self._called_connection_lost = True

    def get_write_buffer_size(self):
        size = self._pending_write
@@ -153,53 +183,127 @@ class _ProactorReadPipeTransport(_ProactorBasePipeTransport,
    """Transport for read pipes."""

    def __init__(self, loop, sock, protocol, waiter=None,
-                 extra=None, server=None):
+                 extra=None, server=None, buffer_size=65536):
+        self._pending_data_length = -1
+        self._paused = True
        super().__init__(loop, sock, protocol, waiter, extra, server)
-        self._paused = False
+
+        self._data = bytearray(buffer_size)
        self._loop.call_soon(self._loop_reading)
+        self._paused = False
+
+    def is_reading(self):
+        return not self._paused and not self._closing

    def pause_reading(self):
-        if self._closing:
-            raise RuntimeError('Cannot pause_reading() when closing')
-        if self._paused:
-            raise RuntimeError('Already paused')
+        if self._closing or self._paused:
+            return
        self._paused = True
+
+        # bpo-33694: Don't cancel self._read_fut because cancelling an
+        # overlapped WSASend() loss silently data with the current proactor
+        # implementation.
+        #
+        # If CancelIoEx() fails with ERROR_NOT_FOUND, it means that WSASend()
+        # completed (even if HasOverlappedIoCompleted() returns 0), but
+        # Overlapped.cancel() currently silently ignores the ERROR_NOT_FOUND
+        # error. Once the overlapped is ignored, the IOCP loop will ignores the
+        # completion I/O event and so not read the result of the overlapped
+        # WSARecv().
+
        if self._loop.get_debug():
            logger.debug("%r pauses reading", self)

    def resume_reading(self):
-        if not self._paused:
-            raise RuntimeError('Not paused')
-        self._paused = False
-        if self._closing:
+        if self._closing or not self._paused:
            return
-        self._loop.call_soon(self._loop_reading, self._read_fut)
+
+        self._paused = False
+        if self._read_fut is None:
+            self._loop.call_soon(self._loop_reading, None)
+
+        length = self._pending_data_length
+        self._pending_data_length = -1
+        if length > -1:
+            # Call the protocol method after calling _loop_reading(),
+            # since the protocol can decide to pause reading again.
+            self._loop.call_soon(self._data_received, self._data[:length], length)
+
        if self._loop.get_debug():
            logger.debug("%r resumes reading", self)

-    def _loop_reading(self, fut=None):
-        if self._paused:
-            return
-        data = None
+    def _eof_received(self):
+        if self._loop.get_debug():
+            logger.debug("%r received EOF", self)

+        try:
+            keep_open = self._protocol.eof_received()
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
+            self._fatal_error(
+                exc, 'Fatal error: protocol.eof_received() call failed.')
+            return
+
+        if not keep_open:
+            self.close()
+
+    def _data_received(self, data, length):
+        if self._paused:
+            # Don't call any protocol method while reading is paused.
+            # The protocol will be called on resume_reading().
+            assert self._pending_data_length == -1
+            self._pending_data_length = length
+            return
+
+        if length == 0:
+            self._eof_received()
+            return
+
+        if isinstance(self._protocol, protocols.BufferedProtocol):
+            try:
+                protocols._feed_data_to_buffered_proto(self._protocol, data)
+            except (SystemExit, KeyboardInterrupt):
+                raise
+            except BaseException as exc:
+                self._fatal_error(exc,
+                                  'Fatal error: protocol.buffer_updated() '
+                                  'call failed.')
+                return
+        else:
+            self._protocol.data_received(data)
+
+    def _loop_reading(self, fut=None):
+        length = -1
+        data = None
        try:
            if fut is not None:
                assert self._read_fut is fut or (self._read_fut is None and
                                                 self._closing)
                self._read_fut = None
-                data = fut.result()  # deliver data later in "finally" clause
+                if fut.done():
+                    # deliver data later in "finally" clause
+                    length = fut.result()
+                    if length == 0:
+                        # we got end-of-file so no need to reschedule a new read
+                        return
+
+                    # It's a new slice so make it immutable so protocols upstream don't have problems
+                    data = bytes(memoryview(self._data)[:length])
+                else:
+                    # the future will be replaced by next proactor.recv call
+                    fut.cancel()

            if self._closing:
                # since close() has been called we ignore any read data
-                data = None
                return

-            if data == b'':
-                # we got end-of-file so no need to reschedule a new read
-                return
+            # bpo-33694: buffer_updated() has currently no fast path because of
+            # a data loss issue caused by overlapped WSASend() cancellation.

-            # reschedule a new read
-            self._read_fut = self._loop._proactor.recv(self._sock, 4096)
+            if not self._paused:
+                # reschedule a new read
+                self._read_fut = self._loop._proactor.recv_into(self._sock, self._data)
        except ConnectionAbortedError as exc:
            if not self._closing:
                self._fatal_error(exc, 'Fatal read error on pipe transport')
@@ -210,32 +314,36 @@ class _ProactorReadPipeTransport(_ProactorBasePipeTransport,
            self._force_close(exc)
        except OSError as exc:
            self._fatal_error(exc, 'Fatal read error on pipe transport')
-        except futures.CancelledError:
+        except exceptions.CancelledError:
            if not self._closing:
                raise
        else:
-            self._read_fut.add_done_callback(self._loop_reading)
+            if not self._paused:
+                self._read_fut.add_done_callback(self._loop_reading)
        finally:
-            if data:
-                self._protocol.data_received(data)
-            elif data is not None:
-                if self._loop.get_debug():
-                    logger.debug("%r received EOF", self)
-                keep_open = self._protocol.eof_received()
-                if not keep_open:
-                    self.close()
+            if length > -1:
+                self._data_received(data, length)


 class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,
                                      transports.WriteTransport):
    """Transport for write pipes."""

+    _start_tls_compatible = True
+
+    def __init__(self, *args, **kw):
+        super().__init__(*args, **kw)
+        self._empty_waiter = None
+
    def write(self, data):
        if not isinstance(data, (bytes, bytearray, memoryview)):
-            raise TypeError('data argument must be byte-ish (%r)',
-                            type(data))
+            raise TypeError(
+                f"data argument must be a bytes-like object, "
+                f"not {type(data).__name__}")
        if self._eof_written:
            raise RuntimeError('write_eof() already called')
+        if self._empty_waiter is not None:
+            raise RuntimeError('unable to write; sendfile is in progress')

        if not data:
            return
@@ -267,6 +375,10 @@ class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,

    def _loop_writing(self, f=None, data=None):
        try:
+            if f is not None and self._write_fut is None and self._closing:
+                # XXX most likely self._force_close() has been called, and
+                # it has set self._write_fut to None.
+                return
            assert f is self._write_fut
            self._write_fut = None
            self._pending_write = 0
@@ -295,6 +407,8 @@ class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,
                    self._maybe_pause_protocol()
                else:
                    self._write_fut.add_done_callback(self._loop_writing)
+            if self._empty_waiter is not None and self._write_fut is None:
+                self._empty_waiter.set_result(None)
        except ConnectionResetError as exc:
            self._force_close(exc)
        except OSError as exc:
@@ -309,6 +423,17 @@ class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,
    def abort(self):
        self._force_close(None)

+    def _make_empty_waiter(self):
+        if self._empty_waiter is not None:
+            raise RuntimeError("Empty waiter is already set")
+        self._empty_waiter = self._loop.create_future()
+        if self._write_fut is None:
+            self._empty_waiter.set_result(None)
+        return self._empty_waiter
+
+    def _reset_empty_waiter(self):
+        self._empty_waiter = None
+

 class _ProactorWritePipeTransport(_ProactorBaseWritePipeTransport):
    def __init__(self, *args, **kw):
@@ -332,6 +457,138 @@ class _ProactorWritePipeTransport(_ProactorBaseWritePipeTransport):
            self.close()


+class _ProactorDatagramTransport(_ProactorBasePipeTransport,
+                                 transports.DatagramTransport):
+    max_size = 256 * 1024
+    def __init__(self, loop, sock, protocol, address=None,
+                 waiter=None, extra=None):
+        self._address = address
+        self._empty_waiter = None
+        self._buffer_size = 0
+        # We don't need to call _protocol.connection_made() since our base
+        # constructor does it for us.
+        super().__init__(loop, sock, protocol, waiter=waiter, extra=extra)
+
+        # The base constructor sets _buffer = None, so we set it here
+        self._buffer = collections.deque()
+        self._loop.call_soon(self._loop_reading)
+
+    def _set_extra(self, sock):
+        _set_socket_extra(self, sock)
+
+    def get_write_buffer_size(self):
+        return self._buffer_size
+
+    def abort(self):
+        self._force_close(None)
+
+    def sendto(self, data, addr=None):
+        if not isinstance(data, (bytes, bytearray, memoryview)):
+            raise TypeError('data argument must be bytes-like object (%r)',
+                            type(data))
+
+        if not data:
+            return
+
+        if self._address is not None and addr not in (None, self._address):
+            raise ValueError(
+                f'Invalid address: must be None or {self._address}')
+
+        if self._conn_lost and self._address:
+            if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
+                logger.warning('socket.sendto() raised exception.')
+            self._conn_lost += 1
+            return
+
+        # Ensure that what we buffer is immutable.
+        self._buffer.append((bytes(data), addr))
+        self._buffer_size += len(data)
+
+        if self._write_fut is None:
+            # No current write operations are active, kick one off
+            self._loop_writing()
+        # else: A write operation is already kicked off
+
+        self._maybe_pause_protocol()
+
+    def _loop_writing(self, fut=None):
+        try:
+            if self._conn_lost:
+                return
+
+            assert fut is self._write_fut
+            self._write_fut = None
+            if fut:
+                # We are in a _loop_writing() done callback, get the result
+                fut.result()
+
+            if not self._buffer or (self._conn_lost and self._address):
+                # The connection has been closed
+                if self._closing:
+                    self._loop.call_soon(self._call_connection_lost, None)
+                return
+
+            data, addr = self._buffer.popleft()
+            self._buffer_size -= len(data)
+            if self._address is not None:
+                self._write_fut = self._loop._proactor.send(self._sock,
+                                                            data)
+            else:
+                self._write_fut = self._loop._proactor.sendto(self._sock,
+                                                              data,
+                                                              addr=addr)
+        except OSError as exc:
+            self._protocol.error_received(exc)
+        except Exception as exc:
+            self._fatal_error(exc, 'Fatal write error on datagram transport')
+        else:
+            self._write_fut.add_done_callback(self._loop_writing)
+            self._maybe_resume_protocol()
+
+    def _loop_reading(self, fut=None):
+        data = None
+        try:
+            if self._conn_lost:
+                return
+
+            assert self._read_fut is fut or (self._read_fut is None and
+                                             self._closing)
+
+            self._read_fut = None
+            if fut is not None:
+                res = fut.result()
+
+                if self._closing:
+                    # since close() has been called we ignore any read data
+                    data = None
+                    return
+
+                if self._address is not None:
+                    data, addr = res, self._address
+                else:
+                    data, addr = res
+
+            if self._conn_lost:
+                return
+            if self._address is not None:
+                self._read_fut = self._loop._proactor.recv(self._sock,
+                                                           self.max_size)
+            else:
+                self._read_fut = self._loop._proactor.recvfrom(self._sock,
+                                                               self.max_size)
+        except OSError as exc:
+            self._protocol.error_received(exc)
+        except exceptions.CancelledError:
+            if not self._closing:
+                raise
+        else:
+            if self._read_fut is not None:
+                self._read_fut.add_done_callback(self._loop_reading)
+        finally:
+            if data:
+                self._protocol.datagram_received(data, addr)
+
+
 class _ProactorDuplexPipeTransport(_ProactorReadPipeTransport,
                                   _ProactorBaseWritePipeTransport,
                                   transports.Transport):
@@ -349,21 +606,15 @@ class _ProactorSocketTransport(_ProactorReadPipeTransport,
                               transports.Transport):
    """Transport for connected sockets."""

+    _sendfile_compatible = constants._SendfileMode.TRY_NATIVE
+
+    def __init__(self, loop, sock, protocol, waiter=None,
+                 extra=None, server=None):
+        super().__init__(loop, sock, protocol, waiter, extra, server)
+        base_events._set_nodelay(sock)
+
    def _set_extra(self, sock):
-        self._extra['socket'] = sock
-        try:
-            self._extra['sockname'] = sock.getsockname()
-        except (socket.error, AttributeError):
-            if self._loop.get_debug():
-                logger.warning("getsockname() failed on %r",
-                             sock, exc_info=True)
-        if 'peername' not in self._extra:
-            try:
-                self._extra['peername'] = sock.getpeername()
-            except (socket.error, AttributeError):
-                if self._loop.get_debug():
-                    logger.warning("getpeername() failed on %r",
-                                   sock, exc_info=True)
+        _set_socket_extra(self, sock)

    def can_write_eof(self):
        return True
@@ -387,26 +638,35 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
        self._accept_futures = {}   # socket file descriptor => Future
        proactor.set_loop(self)
        self._make_self_pipe()
+        if threading.current_thread() is threading.main_thread():
+            # wakeup fd can only be installed to a file descriptor from the main thread
+            signal.set_wakeup_fd(self._csock.fileno())

    def _make_socket_transport(self, sock, protocol, waiter=None,
                               extra=None, server=None):
        return _ProactorSocketTransport(self, sock, protocol, waiter,
                                        extra, server)

-    def _make_ssl_transport(self, rawsock, protocol, sslcontext, waiter=None,
-                            *, server_side=False, server_hostname=None,
-                            extra=None, server=None):
-        if not sslproto._is_sslproto_available():
-            raise NotImplementedError("Proactor event loop requires Python 3.5"
-                                      " or newer (ssl.MemoryBIO) to support "
-                                      "SSL")
-
-        ssl_protocol = sslproto.SSLProtocol(self, protocol, sslcontext, waiter,
-                                            server_side, server_hostname)
+    def _make_ssl_transport(
+            self, rawsock, protocol, sslcontext, waiter=None,
+            *, server_side=False, server_hostname=None,
+            extra=None, server=None,
+            ssl_handshake_timeout=None,
+            ssl_shutdown_timeout=None):
+        ssl_protocol = sslproto.SSLProtocol(
+                self, protocol, sslcontext, waiter,
+                server_side, server_hostname,
+                ssl_handshake_timeout=ssl_handshake_timeout,
+                ssl_shutdown_timeout=ssl_shutdown_timeout)
        _ProactorSocketTransport(self, rawsock, ssl_protocol,
                                 extra=extra, server=server)
        return ssl_protocol._app_transport

+    def _make_datagram_transport(self, sock, protocol,
+                                 address=None, waiter=None, extra=None):
+        return _ProactorDatagramTransport(self, sock, protocol, address,
+                                          waiter, extra)
+
    def _make_duplex_pipe_transport(self, sock, protocol, waiter=None,
                                    extra=None):
        return _ProactorDuplexPipeTransport(self,
@@ -428,6 +688,8 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
        if self.is_closed():
            return

+        if threading.current_thread() is threading.main_thread():
+            signal.set_wakeup_fd(-1)
        # Call these methods before closing the event loop (before calling
        # BaseEventLoop.close), because they can schedule callbacks with
        # call_soon(), which is forbidden when the event loop is closed.
@@ -440,20 +702,73 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
        # Close the event loop
        super().close()

-    def sock_recv(self, sock, n):
-        return self._proactor.recv(sock, n)
+    async def sock_recv(self, sock, n):
+        return await self._proactor.recv(sock, n)

-    def sock_sendall(self, sock, data):
-        return self._proactor.send(sock, data)
+    async def sock_recv_into(self, sock, buf):
+        return await self._proactor.recv_into(sock, buf)

-    def sock_connect(self, sock, address):
-        return self._proactor.connect(sock, address)
+    async def sock_recvfrom(self, sock, bufsize):
+        return await self._proactor.recvfrom(sock, bufsize)

-    def sock_accept(self, sock):
-        return self._proactor.accept(sock)
+    async def sock_recvfrom_into(self, sock, buf, nbytes=0):
+        if not nbytes:
+            nbytes = len(buf)

-    def _socketpair(self):
-        raise NotImplementedError
+        return await self._proactor.recvfrom_into(sock, buf, nbytes)
+
+    async def sock_sendall(self, sock, data):
+        return await self._proactor.send(sock, data)
+
+    async def sock_sendto(self, sock, data, address):
+        return await self._proactor.sendto(sock, data, 0, address)
+
+    async def sock_connect(self, sock, address):
+        return await self._proactor.connect(sock, address)
+
+    async def sock_accept(self, sock):
+        return await self._proactor.accept(sock)
+
+    async def _sock_sendfile_native(self, sock, file, offset, count):
+        try:
+            fileno = file.fileno()
+        except (AttributeError, io.UnsupportedOperation) as err:
+            raise exceptions.SendfileNotAvailableError("not a regular file")
+        try:
+            fsize = os.fstat(fileno).st_size
+        except OSError:
+            raise exceptions.SendfileNotAvailableError("not a regular file")
+        blocksize = count if count else fsize
+        if not blocksize:
+            return 0  # empty file
+
+        blocksize = min(blocksize, 0xffff_ffff)
+        end_pos = min(offset + count, fsize) if count else fsize
+        offset = min(offset, fsize)
+        total_sent = 0
+        try:
+            while True:
+                blocksize = min(end_pos - offset, blocksize)
+                if blocksize <= 0:
+                    return total_sent
+                await self._proactor.sendfile(sock, file, offset, blocksize)
+                offset += blocksize
+                total_sent += blocksize
+        finally:
+            if total_sent > 0:
+                file.seek(offset)
+
+    async def _sendfile_native(self, transp, file, offset, count):
+        resume_reading = transp.is_reading()
+        transp.pause_reading()
+        await transp._make_empty_waiter()
+        try:
+            return await self.sock_sendfile(transp._sock, file, offset, count,
+                                            fallback=False)
+        finally:
+            transp._reset_empty_waiter()
+            if resume_reading:
+                transp.resume_reading()

    def _close_self_pipe(self):
        if self._self_reading_future is not None:
@@ -467,21 +782,30 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):

    def _make_self_pipe(self):
        # A self-socket, really. :-)
-        self._ssock, self._csock = self._socketpair()
+        self._ssock, self._csock = socket.socketpair()
        self._ssock.setblocking(False)
        self._csock.setblocking(False)
        self._internal_fds += 1
-        self.call_soon(self._loop_self_reading)

    def _loop_self_reading(self, f=None):
        try:
            if f is not None:
                f.result()  # may raise
+            if self._self_reading_future is not f:
+                # When we scheduled this Future, we assigned it to
+                # _self_reading_future. If it's not there now, something has
+                # tried to cancel the loop while this callback was still in the
+                # queue (see windows_events.ProactorEventLoop.run_forever). In
+                # that case stop here instead of continuing to schedule a new
+                # iteration.
+                return
            f = self._proactor.recv(self._ssock, 4096)
-        except futures.CancelledError:
+        except exceptions.CancelledError:
            # _close_self_pipe() has been called, stop waiting for data
            return
-        except Exception as exc:
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as exc:
            self.call_exception_handler({
                'message': 'Error on reading from the event loop self pipe',
                'exception': exc,
@@ -492,10 +816,27 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
            f.add_done_callback(self._loop_self_reading)

    def _write_to_self(self):
-        self._csock.send(b'\0')
+        # This may be called from a different thread, possibly after
+        # _close_self_pipe() has been called or even while it is
+        # running.  Guard for self._csock being None or closed.  When
+        # a socket is closed, send() raises OSError (with errno set to
+        # EBADF, but let's not rely on the exact error code).
+        csock = self._csock
+        if csock is None:
+            return
+
+        try:
+            csock.send(b'\0')
+        except OSError:
+            if self._debug:
+                logger.debug("Fail to write a null byte into the "
+                             "self-pipe socket",
+                             exc_info=True)

    def _start_serving(self, protocol_factory, sock,
-                       sslcontext=None, server=None, backlog=100):
+                       sslcontext=None, server=None, backlog=100,
+                       ssl_handshake_timeout=None,
+                       ssl_shutdown_timeout=None):

        def loop(f=None):
            try:
@@ -508,7 +849,9 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
                    if sslcontext is not None:
                        self._make_ssl_transport(
                            conn, protocol, sslcontext, server_side=True,
-                            extra={'peername': addr}, server=server)
+                            extra={'peername': addr}, server=server,
+                            ssl_handshake_timeout=ssl_handshake_timeout,
+                            ssl_shutdown_timeout=ssl_shutdown_timeout)
                    else:
                        self._make_socket_transport(
                            conn, protocol,
@@ -521,13 +864,13 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
                    self.call_exception_handler({
                        'message': 'Accept failed on a socket',
                        'exception': exc,
-                        'socket': sock,
+                        'socket': trsock.TransportSocket(sock),
                    })
                    sock.close()
                elif self._debug:
                    logger.debug("Accept failed on socket %r",
                                 sock, exc_info=True)
-            except futures.CancelledError:
+            except exceptions.CancelledError:
                sock.close()
            else:
                self._accept_futures[sock.fileno()] = f
@@ -545,6 +888,8 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
        self._accept_futures.clear()

    def _stop_serving(self, sock):
-        self._stop_accept_futures()
+        future = self._accept_futures.pop(sock.fileno(), None)
+        if future:
+            future.cancel()
        self._proactor._stop_serving(sock)
        sock.close()
--- a/Lib/asyncio/protocols.py
+++ b/Lib/asyncio/protocols.py
@@ -1,7 +1,9 @@
-"""Abstract Protocol class."""
+"""Abstract Protocol base classes."""

-__all__ = ['BaseProtocol', 'Protocol', 'DatagramProtocol',
-           'SubprocessProtocol']
+__all__ = (
+    'BaseProtocol', 'Protocol', 'DatagramProtocol',
+    'SubprocessProtocol', 'BufferedProtocol',
+)


 class BaseProtocol:
@@ -14,6 +16,8 @@ class BaseProtocol:
    write-only transport like write pipe
    """

+    __slots__ = ()
+
    def connection_made(self, transport):
        """Called when a connection is made.

@@ -85,6 +89,8 @@ class Protocol(BaseProtocol):
    * CL: connection_lost()
    """

+    __slots__ = ()
+
    def data_received(self, data):
        """Called when some data is received.

@@ -100,9 +106,64 @@ class Protocol(BaseProtocol):
        """


+class BufferedProtocol(BaseProtocol):
+    """Interface for stream protocol with manual buffer control.
+
+    Event methods, such as `create_server` and `create_connection`,
+    accept factories that return protocols that implement this interface.
+
+    The idea of BufferedProtocol is that it allows to manually allocate
+    and control the receive buffer.  Event loops can then use the buffer
+    provided by the protocol to avoid unnecessary data copies.  This
+    can result in noticeable performance improvement for protocols that
+    receive big amounts of data.  Sophisticated protocols can allocate
+    the buffer only once at creation time.
+
+    State machine of calls:
+
+      start -> CM [-> GB [-> BU?]]* [-> ER?] -> CL -> end
+
+    * CM: connection_made()
+    * GB: get_buffer()
+    * BU: buffer_updated()
+    * ER: eof_received()
+    * CL: connection_lost()
+    """
+
+    __slots__ = ()
+
+    def get_buffer(self, sizehint):
+        """Called to allocate a new receive buffer.
+
+        *sizehint* is a recommended minimal size for the returned
+        buffer.  When set to -1, the buffer size can be arbitrary.
+
+        Must return an object that implements the
+        :ref:`buffer protocol <bufferobjects>`.
+        It is an error to return a zero-sized buffer.
+        """
+
+    def buffer_updated(self, nbytes):
+        """Called when the buffer was updated with the received data.
+
+        *nbytes* is the total number of bytes that were written to
+        the buffer.
+        """
+
+    def eof_received(self):
+        """Called when the other end calls write_eof() or equivalent.
+
+        If this returns a false value (including None), the transport
+        will close itself.  If it returns a true value, closing the
+        transport is up to the protocol.
+        """
+
+
 class DatagramProtocol(BaseProtocol):
    """Interface for datagram protocol."""

+    __slots__ = ()
+
    def datagram_received(self, data, addr):
        """Called when some datagram is received."""

@@ -116,6 +177,8 @@ class DatagramProtocol(BaseProtocol):
 class SubprocessProtocol(BaseProtocol):
    """Interface for protocol for subprocess calls."""

+    __slots__ = ()
+
    def pipe_data_received(self, fd, data):
        """Called when the subprocess writes data into stdout/stderr pipe.

@@ -132,3 +195,22 @@ class SubprocessProtocol(BaseProtocol):

    def process_exited(self):
        """Called when subprocess has exited."""
+
+
+def _feed_data_to_buffered_proto(proto, data):
+    data_len = len(data)
+    while data_len:
+        buf = proto.get_buffer(data_len)
+        buf_len = len(buf)
+        if not buf_len:
+            raise RuntimeError('get_buffer() returned an empty buffer')
+
+        if buf_len >= data_len:
+            buf[:data_len] = data
+            proto.buffer_updated(data_len)
+            return
+        else:
+            buf[:buf_len] = data[:buf_len]
+            proto.buffer_updated(buf_len)
+            data = data[buf_len:]
+            data_len = len(data)
--- a/Lib/asyncio/queues.py
+++ b/Lib/asyncio/queues.py
@@ -1,35 +1,28 @@
-"""Queues"""
-
-__all__ = ['Queue', 'PriorityQueue', 'LifoQueue', 'QueueFull', 'QueueEmpty']
+__all__ = ('Queue', 'PriorityQueue', 'LifoQueue', 'QueueFull', 'QueueEmpty')

 import collections
 import heapq
+from types import GenericAlias

-from . import compat
-from . import events
 from . import locks
-from .coroutines import coroutine
+from . import mixins


 class QueueEmpty(Exception):
-    """Exception raised when Queue.get_nowait() is called on a Queue object
-    which is empty.
-    """
+    """Raised when Queue.get_nowait() is called on an empty Queue."""
    pass


 class QueueFull(Exception):
-    """Exception raised when the Queue.put_nowait() method is called on a Queue
-    object which is full.
-    """
+    """Raised when the Queue.put_nowait() method is called on a full Queue."""
    pass


-class Queue:
+class Queue(mixins._LoopBoundMixin):
    """A queue, useful for coordinating producer and consumer coroutines.

    If maxsize is less than or equal to zero, the queue size is infinite. If it
-    is an integer greater than 0, then "yield from put()" will block when the
+    is an integer greater than 0, then "await put()" will block when the
    queue reaches maxsize, until an item is removed by get().

    Unlike the standard library Queue, you can reliably know this Queue's size
@@ -37,11 +30,7 @@ class Queue:
    interrupted between calling qsize() and doing an operation on the Queue.
    """

-    def __init__(self, maxsize=0, *, loop=None):
-        if loop is None:
-            self._loop = events.get_event_loop()
-        else:
-            self._loop = loop
+    def __init__(self, maxsize=0):
        self._maxsize = maxsize

        # Futures.
@@ -49,7 +38,7 @@ class Queue:
        # Futures.
        self._putters = collections.deque()
        self._unfinished_tasks = 0
-        self._finished = locks.Event(loop=self._loop)
+        self._finished = locks.Event()
        self._finished.set()
        self._init(maxsize)

@@ -75,25 +64,23 @@ class Queue:
                break

    def __repr__(self):
-        return '<{} at {:#x} {}>'.format(
-            type(self).__name__, id(self), self._format())
+        return f'<{type(self).__name__} at {id(self):#x} {self._format()}>'

    def __str__(self):
-        return '<{} {}>'.format(type(self).__name__, self._format())
+        return f'<{type(self).__name__} {self._format()}>'

-    def __class_getitem__(cls, type):
-        return cls
+    __class_getitem__ = classmethod(GenericAlias)

    def _format(self):
-        result = 'maxsize={!r}'.format(self._maxsize)
+        result = f'maxsize={self._maxsize!r}'
        if getattr(self, '_queue', None):
-            result += ' _queue={!r}'.format(list(self._queue))
+            result += f' _queue={list(self._queue)!r}'
        if self._getters:
-            result += ' _getters[{}]'.format(len(self._getters))
+            result += f' _getters[{len(self._getters)}]'
        if self._putters:
-            result += ' _putters[{}]'.format(len(self._putters))
+            result += f' _putters[{len(self._putters)}]'
        if self._unfinished_tasks:
-            result += ' tasks={}'.format(self._unfinished_tasks)
+            result += f' tasks={self._unfinished_tasks}'
        return result

    def qsize(self):
@@ -120,22 +107,26 @@ class Queue:
        else:
            return self.qsize() >= self._maxsize

-    @coroutine
-    def put(self, item):
+    async def put(self, item):
        """Put an item into the queue.

        Put an item into the queue. If the queue is full, wait until a free
        slot is available before adding item.
-
-        This method is a coroutine.
        """
        while self.full():
-            putter = self._loop.create_future()
+            putter = self._get_loop().create_future()
            self._putters.append(putter)
            try:
-                yield from putter
+                await putter
            except:
                putter.cancel()  # Just in case putter is not done yet.
+                try:
+                    # Clean self._putters from canceled putters.
+                    self._putters.remove(putter)
+                except ValueError:
+                    # The putter could be removed from self._putters by a
+                    # previous get_nowait call.
+                    pass
                if not self.full() and not putter.cancelled():
                    # We were woken up by get_nowait(), but can't take
                    # the call.  Wake up the next in line.
@@ -155,21 +146,25 @@ class Queue:
        self._finished.clear()
        self._wakeup_next(self._getters)

-    @coroutine
-    def get(self):
+    async def get(self):
        """Remove and return an item from the queue.

        If queue is empty, wait until an item is available.
-
-        This method is a coroutine.
        """
        while self.empty():
-            getter = self._loop.create_future()
+            getter = self._get_loop().create_future()
            self._getters.append(getter)
            try:
-                yield from getter
+                await getter
            except:
                getter.cancel()  # Just in case getter is not done yet.
+                try:
+                    # Clean self._getters from canceled getters.
+                    self._getters.remove(getter)
+                except ValueError:
+                    # The getter could be removed from self._getters by a
+                    # previous put_nowait call.
+                    pass
                if not self.empty() and not getter.cancelled():
                    # We were woken up by put_nowait(), but can't take
                    # the call.  Wake up the next in line.
@@ -208,8 +203,7 @@ class Queue:
        if self._unfinished_tasks == 0:
            self._finished.set()

-    @coroutine
-    def join(self):
+    async def join(self):
        """Block until all items in the queue have been gotten and processed.

        The count of unfinished tasks goes up whenever an item is added to the
@@ -218,7 +212,7 @@ class Queue:
        When the count of unfinished tasks drops to zero, join() unblocks.
        """
        if self._unfinished_tasks > 0:
-            yield from self._finished.wait()
+            await self._finished.wait()


 class PriorityQueue(Queue):
@@ -248,9 +242,3 @@ class LifoQueue(Queue):

    def _get(self):
        return self._queue.pop()
-
-
-if not compat.PY35:
-    JoinableQueue = Queue
-    """Deprecated alias for Queue."""
-    __all__.append('JoinableQueue')
--- a/Lib/asyncio/runners.py
+++ b/Lib/asyncio/runners.py
@@ -1,16 +1,168 @@
-__all__ = ['run']
+__all__ = ('Runner', 'run')

+import contextvars
+import enum
+import functools
+import threading
+import signal
 from . import coroutines
 from . import events
+from . import exceptions
 from . import tasks
+from . import constants
+
+class _State(enum.Enum):
+    CREATED = "created"
+    INITIALIZED = "initialized"
+    CLOSED = "closed"


-def run(main, *, debug=False):
-    """Run a coroutine.
+class Runner:
+    """A context manager that controls event loop life cycle.
+
+    The context manager always creates a new event loop,
+    allows to run async functions inside it,
+    and properly finalizes the loop at the context manager exit.
+
+    If debug is True, the event loop will be run in debug mode.
+    If loop_factory is passed, it is used for new event loop creation.
+
+    asyncio.run(main(), debug=True)
+
+    is a shortcut for
+
+    with asyncio.Runner(debug=True) as runner:
+        runner.run(main())
+
+    The run() method can be called multiple times within the runner's context.
+
+    This can be useful for interactive console (e.g. IPython),
+    unittest runners, console tools, -- everywhere when async code
+    is called from existing sync framework and where the preferred single
+    asyncio.run() call doesn't work.
+
+    """
+
+    # Note: the class is final, it is not intended for inheritance.
+
+    def __init__(self, *, debug=None, loop_factory=None):
+        self._state = _State.CREATED
+        self._debug = debug
+        self._loop_factory = loop_factory
+        self._loop = None
+        self._context = None
+        self._interrupt_count = 0
+        self._set_event_loop = False
+
+    def __enter__(self):
+        self._lazy_init()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+
+    def close(self):
+        """Shutdown and close event loop."""
+        if self._state is not _State.INITIALIZED:
+            return
+        try:
+            loop = self._loop
+            _cancel_all_tasks(loop)
+            loop.run_until_complete(loop.shutdown_asyncgens())
+            loop.run_until_complete(
+                loop.shutdown_default_executor(constants.THREAD_JOIN_TIMEOUT))
+        finally:
+            if self._set_event_loop:
+                events.set_event_loop(None)
+            loop.close()
+            self._loop = None
+            self._state = _State.CLOSED
+
+    def get_loop(self):
+        """Return embedded event loop."""
+        self._lazy_init()
+        return self._loop
+
+    def run(self, coro, *, context=None):
+        """Run a coroutine inside the embedded event loop."""
+        if not coroutines.iscoroutine(coro):
+            raise ValueError("a coroutine was expected, got {!r}".format(coro))
+
+        if events._get_running_loop() is not None:
+            # fail fast with short traceback
+            raise RuntimeError(
+                "Runner.run() cannot be called from a running event loop")
+
+        self._lazy_init()
+
+        if context is None:
+            context = self._context
+        task = self._loop.create_task(coro, context=context)
+
+        if (threading.current_thread() is threading.main_thread()
+            and signal.getsignal(signal.SIGINT) is signal.default_int_handler
+        ):
+            sigint_handler = functools.partial(self._on_sigint, main_task=task)
+            try:
+                signal.signal(signal.SIGINT, sigint_handler)
+            except ValueError:
+                # `signal.signal` may throw if `threading.main_thread` does
+                # not support signals (e.g. embedded interpreter with signals
+                # not registered - see gh-91880)
+                sigint_handler = None
+        else:
+            sigint_handler = None
+
+        self._interrupt_count = 0
+        try:
+            return self._loop.run_until_complete(task)
+        except exceptions.CancelledError:
+            if self._interrupt_count > 0:
+                uncancel = getattr(task, "uncancel", None)
+                if uncancel is not None and uncancel() == 0:
+                    raise KeyboardInterrupt()
+            raise  # CancelledError
+        finally:
+            if (sigint_handler is not None
+                and signal.getsignal(signal.SIGINT) is sigint_handler
+            ):
+                signal.signal(signal.SIGINT, signal.default_int_handler)
+
+    def _lazy_init(self):
+        if self._state is _State.CLOSED:
+            raise RuntimeError("Runner is closed")
+        if self._state is _State.INITIALIZED:
+            return
+        if self._loop_factory is None:
+            self._loop = events.new_event_loop()
+            if not self._set_event_loop:
+                # Call set_event_loop only once to avoid calling
+                # attach_loop multiple times on child watchers
+                events.set_event_loop(self._loop)
+                self._set_event_loop = True
+        else:
+            self._loop = self._loop_factory()
+        if self._debug is not None:
+            self._loop.set_debug(self._debug)
+        self._context = contextvars.copy_context()
+        self._state = _State.INITIALIZED
+
+    def _on_sigint(self, signum, frame, main_task):
+        self._interrupt_count += 1
+        if self._interrupt_count == 1 and not main_task.done():
+            main_task.cancel()
+            # wakeup loop if it is blocked by select() with long timeout
+            self._loop.call_soon_threadsafe(lambda: None)
+            return
+        raise KeyboardInterrupt()
+
+
+def run(main, *, debug=None, loop_factory=None):
+    """Execute the coroutine and return the result.

    This function runs the passed coroutine, taking care of
-    managing the asyncio event loop and finalizing asynchronous
-    generators.
+    managing the asyncio event loop, finalizing asynchronous
+    generators and closing the default executor.

    This function cannot be called when another asyncio event loop is
    running in the same thread.
@@ -21,6 +173,10 @@ def run(main, *, debug=False):
    It should be used as a main entry point for asyncio programs, and should
    ideally only be called once.

+    The executor is given a timeout duration of 5 minutes to shutdown.
+    If the executor hasn't finished within that duration, a warning is
+    emitted and the executor is closed.
+
    Example:

        async def main():
@@ -30,24 +186,12 @@ def run(main, *, debug=False):
        asyncio.run(main())
    """
    if events._get_running_loop() is not None:
+        # fail fast with short traceback
        raise RuntimeError(
            "asyncio.run() cannot be called from a running event loop")

-    if not coroutines.iscoroutine(main):
-        raise ValueError("a coroutine was expected, got {!r}".format(main))
-
-    loop = events.new_event_loop()
-    try:
-        events.set_event_loop(loop)
-        loop.set_debug(debug)
-        return loop.run_until_complete(main)
-    finally:
-        try:
-            _cancel_all_tasks(loop)
-            loop.run_until_complete(loop.shutdown_asyncgens())
-        finally:
-            events.set_event_loop(None)
-            loop.close()
+    with Runner(debug=debug, loop_factory=loop_factory) as runner:
+        return runner.run(main)


 def _cancel_all_tasks(loop):
@@ -58,8 +202,7 @@ def _cancel_all_tasks(loop):
    for task in to_cancel:
        task.cancel()

-    loop.run_until_complete(
-        tasks.gather(*to_cancel, loop=loop, return_exceptions=True))
+    loop.run_until_complete(tasks.gather(*to_cancel, return_exceptions=True))

    for task in to_cancel:
        if task.cancelled():
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
--- a/Lib/asyncio/sslproto.py
+++ b/Lib/asyncio/sslproto.py
--- a/Lib/asyncio/staggered.py
+++ b/Lib/asyncio/staggered.py
@@ -0,0 +1,149 @@
+"""Support for running coroutines in parallel with staggered start times."""
+
+__all__ = 'staggered_race',
+
+import contextlib
+import typing
+
+from . import events
+from . import exceptions as exceptions_mod
+from . import locks
+from . import tasks
+
+
+async def staggered_race(
+        coro_fns: typing.Iterable[typing.Callable[[], typing.Awaitable]],
+        delay: typing.Optional[float],
+        *,
+        loop: events.AbstractEventLoop = None,
+) -> typing.Tuple[
+    typing.Any,
+    typing.Optional[int],
+    typing.List[typing.Optional[Exception]]
+]:
+    """Run coroutines with staggered start times and take the first to finish.
+
+    This method takes an iterable of coroutine functions. The first one is
+    started immediately. From then on, whenever the immediately preceding one
+    fails (raises an exception), or when *delay* seconds has passed, the next
+    coroutine is started. This continues until one of the coroutines complete
+    successfully, in which case all others are cancelled, or until all
+    coroutines fail.
+
+    The coroutines provided should be well-behaved in the following way:
+
+    * They should only ``return`` if completed successfully.
+
+    * They should always raise an exception if they did not complete
+      successfully. In particular, if they handle cancellation, they should
+      probably reraise, like this::
+
+        try:
+            # do work
+        except asyncio.CancelledError:
+            # undo partially completed work
+            raise
+
+    Args:
+        coro_fns: an iterable of coroutine functions, i.e. callables that
+            return a coroutine object when called. Use ``functools.partial`` or
+            lambdas to pass arguments.
+
+        delay: amount of time, in seconds, between starting coroutines. If
+            ``None``, the coroutines will run sequentially.
+
+        loop: the event loop to use.
+
+    Returns:
+        tuple *(winner_result, winner_index, exceptions)* where
+
+        - *winner_result*: the result of the winning coroutine, or ``None``
+          if no coroutines won.
+
+        - *winner_index*: the index of the winning coroutine in
+          ``coro_fns``, or ``None`` if no coroutines won. If the winning
+          coroutine may return None on success, *winner_index* can be used
+          to definitively determine whether any coroutine won.
+
+        - *exceptions*: list of exceptions returned by the coroutines.
+          ``len(exceptions)`` is equal to the number of coroutines actually
+          started, and the order is the same as in ``coro_fns``. The winning
+          coroutine's entry is ``None``.
+
+    """
+    # TODO: when we have aiter() and anext(), allow async iterables in coro_fns.
+    loop = loop or events.get_running_loop()
+    enum_coro_fns = enumerate(coro_fns)
+    winner_result = None
+    winner_index = None
+    exceptions = []
+    running_tasks = []
+
+    async def run_one_coro(
+            previous_failed: typing.Optional[locks.Event]) -> None:
+        # Wait for the previous task to finish, or for delay seconds
+        if previous_failed is not None:
+            with contextlib.suppress(exceptions_mod.TimeoutError):
+                # Use asyncio.wait_for() instead of asyncio.wait() here, so
+                # that if we get cancelled at this point, Event.wait() is also
+                # cancelled, otherwise there will be a "Task destroyed but it is
+                # pending" later.
+                await tasks.wait_for(previous_failed.wait(), delay)
+        # Get the next coroutine to run
+        try:
+            this_index, coro_fn = next(enum_coro_fns)
+        except StopIteration:
+            return
+        # Start task that will run the next coroutine
+        this_failed = locks.Event()
+        next_task = loop.create_task(run_one_coro(this_failed))
+        running_tasks.append(next_task)
+        assert len(running_tasks) == this_index + 2
+        # Prepare place to put this coroutine's exceptions if not won
+        exceptions.append(None)
+        assert len(exceptions) == this_index + 1
+
+        try:
+            result = await coro_fn()
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except BaseException as e:
+            exceptions[this_index] = e
+            this_failed.set()  # Kickstart the next coroutine
+        else:
+            # Store winner's results
+            nonlocal winner_index, winner_result
+            assert winner_index is None
+            winner_index = this_index
+            winner_result = result
+            # Cancel all other tasks. We take care to not cancel the current
+            # task as well. If we do so, then since there is no `await` after
+            # here and CancelledError are usually thrown at one, we will
+            # encounter a curious corner case where the current task will end
+            # up as done() == True, cancelled() == False, exception() ==
+            # asyncio.CancelledError. This behavior is specified in
+            # https://bugs.python.org/issue30048
+            for i, t in enumerate(running_tasks):
+                if i != this_index:
+                    t.cancel()
+
+    first_task = loop.create_task(run_one_coro(None))
+    running_tasks.append(first_task)
+    try:
+        # Wait for a growing list of tasks to all finish: poor man's version of
+        # curio's TaskGroup or trio's nursery
+        done_count = 0
+        while done_count != len(running_tasks):
+            done, _ = await tasks.wait(running_tasks)
+            done_count = len(done)
+            # If run_one_coro raises an unhandled exception, it's probably a
+            # programming error, and I want to see it.
+            if __debug__:
+                for d in done:
+                    if d.done() and not d.cancelled() and d.exception():
+                        raise d.exception()
+        return winner_result, winner_index, exceptions
+    finally:
+        # Make sure no tasks are left running if we leave this function
+        for t in running_tasks:
+            t.cancel()
--- a/Lib/asyncio/streams.py
+++ b/Lib/asyncio/streams.py
@@ -1,55 +1,30 @@
-"""Stream-related things."""
-
-__all__ = ['StreamReader', 'StreamWriter', 'StreamReaderProtocol',
-           'open_connection', 'start_server',
-           'IncompleteReadError',
-           'LimitOverrunError',
-           ]
+__all__ = (
+    'StreamReader', 'StreamWriter', 'StreamReaderProtocol',
+    'open_connection', 'start_server')

+import collections
 import socket
+import sys
+import warnings
+import weakref

 if hasattr(socket, 'AF_UNIX'):
-    __all__.extend(['open_unix_connection', 'start_unix_server'])
+    __all__ += ('open_unix_connection', 'start_unix_server')

 from . import coroutines
-from . import compat
 from . import events
+from . import exceptions
+from . import format_helpers
 from . import protocols
-from .coroutines import coroutine
 from .log import logger
+from .tasks import sleep


-_DEFAULT_LIMIT = 2 ** 16
+_DEFAULT_LIMIT = 2 ** 16  # 64 KiB


-class IncompleteReadError(EOFError):
-    """
-    Incomplete read error. Attributes:
-
-    - partial: read bytes string before the end of stream was reached
-    - expected: total number of expected bytes (or None if unknown)
-    """
-    def __init__(self, partial, expected):
-        super().__init__("%d bytes read on a total of %r expected bytes"
-                         % (len(partial), expected))
-        self.partial = partial
-        self.expected = expected
-
-
-class LimitOverrunError(Exception):
-    """Reached the buffer limit while looking for a separator.
-
-    Attributes:
-    - consumed: total number of to be consumed bytes.
-    """
-    def __init__(self, message, consumed):
-        super().__init__(message)
-        self.consumed = consumed
-
-
-@coroutine
-def open_connection(host=None, port=None, *,
-                    loop=None, limit=_DEFAULT_LIMIT, **kwds):
+async def open_connection(host=None, port=None, *,
+                          limit=_DEFAULT_LIMIT, **kwds):
    """A wrapper for create_connection() returning a (reader, writer) pair.

    The reader returned is a StreamReader instance; the writer is a
@@ -67,19 +42,17 @@ def open_connection(host=None, port=None, *,
    StreamReaderProtocol classes, just copy the code -- there's
    really nothing special here except some convenience.)
    """
-    if loop is None:
-        loop = events.get_event_loop()
+    loop = events.get_running_loop()
    reader = StreamReader(limit=limit, loop=loop)
    protocol = StreamReaderProtocol(reader, loop=loop)
-    transport, _ = yield from loop.create_connection(
+    transport, _ = await loop.create_connection(
        lambda: protocol, host, port, **kwds)
    writer = StreamWriter(transport, protocol, reader, loop)
    return reader, writer


-@coroutine
-def start_server(client_connected_cb, host=None, port=None, *,
-                 loop=None, limit=_DEFAULT_LIMIT, **kwds):
+async def start_server(client_connected_cb, host=None, port=None, *,
+                       limit=_DEFAULT_LIMIT, **kwds):
    """Start a socket server, call back for each client connected.

    The first parameter, `client_connected_cb`, takes two parameters:
@@ -94,15 +67,13 @@ def start_server(client_connected_cb, host=None, port=None, *,
    positional host and port, with various optional keyword arguments
    following.  The return value is the same as loop.create_server().

-    Additional optional keyword arguments are loop (to set the event loop
-    instance to use) and limit (to set the buffer limit passed to the
-    StreamReader).
+    Additional optional keyword argument is limit (to set the buffer
+    limit passed to the StreamReader).

    The return value is the same as loop.create_server(), i.e. a
    Server object which can be used to stop the service.
    """
-    if loop is None:
-        loop = events.get_event_loop()
+    loop = events.get_running_loop()

    def factory():
        reader = StreamReader(limit=limit, loop=loop)
@@ -110,31 +81,28 @@ def start_server(client_connected_cb, host=None, port=None, *,
                                        loop=loop)
        return protocol

-    return (yield from loop.create_server(factory, host, port, **kwds))
+    return await loop.create_server(factory, host, port, **kwds)


 if hasattr(socket, 'AF_UNIX'):
    # UNIX Domain Sockets are supported on this platform

-    @coroutine
-    def open_unix_connection(path=None, *,
-                             loop=None, limit=_DEFAULT_LIMIT, **kwds):
+    async def open_unix_connection(path=None, *,
+                                   limit=_DEFAULT_LIMIT, **kwds):
        """Similar to `open_connection` but works with UNIX Domain Sockets."""
-        if loop is None:
-            loop = events.get_event_loop()
+        loop = events.get_running_loop()
+
        reader = StreamReader(limit=limit, loop=loop)
        protocol = StreamReaderProtocol(reader, loop=loop)
-        transport, _ = yield from loop.create_unix_connection(
+        transport, _ = await loop.create_unix_connection(
            lambda: protocol, path, **kwds)
        writer = StreamWriter(transport, protocol, reader, loop)
        return reader, writer

-    @coroutine
-    def start_unix_server(client_connected_cb, path=None, *,
-                          loop=None, limit=_DEFAULT_LIMIT, **kwds):
+    async def start_unix_server(client_connected_cb, path=None, *,
+                                limit=_DEFAULT_LIMIT, **kwds):
        """Similar to `start_server` but works with UNIX Domain Sockets."""
-        if loop is None:
-            loop = events.get_event_loop()
+        loop = events.get_running_loop()

        def factory():
            reader = StreamReader(limit=limit, loop=loop)
@@ -142,14 +110,14 @@ if hasattr(socket, 'AF_UNIX'):
                                            loop=loop)
            return protocol

-        return (yield from loop.create_unix_server(factory, path, **kwds))
+        return await loop.create_unix_server(factory, path, **kwds)


 class FlowControlMixin(protocols.Protocol):
    """Reusable flow control logic for StreamWriter.drain().

    This implements the protocol methods pause_writing(),
-    resume_reading() and connection_lost().  If the subclass overrides
+    resume_writing() and connection_lost().  If the subclass overrides
    these it must call the super methods.

    StreamWriter.drain() must wait for _drain_helper() coroutine.
@@ -161,7 +129,7 @@ class FlowControlMixin(protocols.Protocol):
        else:
            self._loop = loop
        self._paused = False
-        self._drain_waiter = None
+        self._drain_waiters = collections.deque()
        self._connection_lost = False

    def pause_writing(self):
@@ -176,39 +144,37 @@ class FlowControlMixin(protocols.Protocol):
        if self._loop.get_debug():
            logger.debug("%r resumes writing", self)

-        waiter = self._drain_waiter
-        if waiter is not None:
-            self._drain_waiter = None
+        for waiter in self._drain_waiters:
            if not waiter.done():
                waiter.set_result(None)

    def connection_lost(self, exc):
        self._connection_lost = True
-        # Wake up the writer if currently paused.
+        # Wake up the writer(s) if currently paused.
        if not self._paused:
            return
-        waiter = self._drain_waiter
-        if waiter is None:
-            return
-        self._drain_waiter = None
-        if waiter.done():
-            return
-        if exc is None:
-            waiter.set_result(None)
-        else:
-            waiter.set_exception(exc)

-    @coroutine
-    def _drain_helper(self):
+        for waiter in self._drain_waiters:
+            if not waiter.done():
+                if exc is None:
+                    waiter.set_result(None)
+                else:
+                    waiter.set_exception(exc)
+
+    async def _drain_helper(self):
        if self._connection_lost:
            raise ConnectionResetError('Connection lost')
        if not self._paused:
            return
-        waiter = self._drain_waiter
-        assert waiter is None or waiter.cancelled()
        waiter = self._loop.create_future()
-        self._drain_waiter = waiter
-        yield from waiter
+        self._drain_waiters.append(waiter)
+        try:
+            await waiter
+        finally:
+            self._drain_waiters.remove(waiter)
+
+    def _get_close_waiter(self, stream):
+        raise NotImplementedError


 class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
@@ -220,40 +186,110 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
    call inappropriate methods of the protocol.)
    """

+    _source_traceback = None
+
    def __init__(self, stream_reader, client_connected_cb=None, loop=None):
        super().__init__(loop=loop)
-        self._stream_reader = stream_reader
+        if stream_reader is not None:
+            self._stream_reader_wr = weakref.ref(stream_reader)
+            self._source_traceback = stream_reader._source_traceback
+        else:
+            self._stream_reader_wr = None
+        if client_connected_cb is not None:
+            # This is a stream created by the `create_server()` function.
+            # Keep a strong reference to the reader until a connection
+            # is established.
+            self._strong_reader = stream_reader
+        self._reject_connection = False
        self._stream_writer = None
+        self._task = None
+        self._transport = None
        self._client_connected_cb = client_connected_cb
        self._over_ssl = False
+        self._closed = self._loop.create_future()
+
+    @property
+    def _stream_reader(self):
+        if self._stream_reader_wr is None:
+            return None
+        return self._stream_reader_wr()
+
+    def _replace_writer(self, writer):
+        loop = self._loop
+        transport = writer.transport
+        self._stream_writer = writer
+        self._transport = transport
+        self._over_ssl = transport.get_extra_info('sslcontext') is not None

    def connection_made(self, transport):
-        self._stream_reader.set_transport(transport)
+        if self._reject_connection:
+            context = {
+                'message': ('An open stream was garbage collected prior to '
+                            'establishing network connection; '
+                            'call "stream.close()" explicitly.')
+            }
+            if self._source_traceback:
+                context['source_traceback'] = self._source_traceback
+            self._loop.call_exception_handler(context)
+            transport.abort()
+            return
+        self._transport = transport
+        reader = self._stream_reader
+        if reader is not None:
+            reader.set_transport(transport)
        self._over_ssl = transport.get_extra_info('sslcontext') is not None
        if self._client_connected_cb is not None:
            self._stream_writer = StreamWriter(transport, self,
-                                               self._stream_reader,
+                                               reader,
                                               self._loop)
-            res = self._client_connected_cb(self._stream_reader,
+            res = self._client_connected_cb(reader,
                                            self._stream_writer)
            if coroutines.iscoroutine(res):
-                self._loop.create_task(res)
+                def callback(task):
+                    if task.cancelled():
+                        transport.close()
+                        return
+                    exc = task.exception()
+                    if exc is not None:
+                        self._loop.call_exception_handler({
+                            'message': 'Unhandled exception in client_connected_cb',
+                            'exception': exc,
+                            'transport': transport,
+                        })
+                        transport.close()
+
+                self._task = self._loop.create_task(res)
+                self._task.add_done_callback(callback)
+
+            self._strong_reader = None

    def connection_lost(self, exc):
-        if self._stream_reader is not None:
+        reader = self._stream_reader
+        if reader is not None:
            if exc is None:
-                self._stream_reader.feed_eof()
+                reader.feed_eof()
            else:
-                self._stream_reader.set_exception(exc)
+                reader.set_exception(exc)
+        if not self._closed.done():
+            if exc is None:
+                self._closed.set_result(None)
+            else:
+                self._closed.set_exception(exc)
        super().connection_lost(exc)
-        self._stream_reader = None
+        self._stream_reader_wr = None
        self._stream_writer = None
+        self._task = None
+        self._transport = None

    def data_received(self, data):
-        self._stream_reader.feed_data(data)
+        reader = self._stream_reader
+        if reader is not None:
+            reader.feed_data(data)

    def eof_received(self):
-        self._stream_reader.feed_eof()
+        reader = self._stream_reader
+        if reader is not None:
+            reader.feed_eof()
        if self._over_ssl:
            # Prevent a warning in SSLProtocol.eof_received:
            # "returning true from eof_received()
@@ -261,6 +297,20 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
            return False
        return True

+    def _get_close_waiter(self, stream):
+        return self._closed
+
+    def __del__(self):
+        # Prevent reports about unhandled exceptions.
+        # Better than self._closed._log_traceback = False hack
+        try:
+            closed = self._closed
+        except AttributeError:
+            pass  # failed constructor
+        else:
+            if closed.done() and not closed.cancelled():
+                closed.exception()
+

 class StreamWriter:
    """Wraps a Transport.
@@ -279,12 +329,14 @@ class StreamWriter:
        assert reader is None or isinstance(reader, StreamReader)
        self._reader = reader
        self._loop = loop
+        self._complete_fut = self._loop.create_future()
+        self._complete_fut.set_result(None)

    def __repr__(self):
-        info = [self.__class__.__name__, 'transport=%r' % self._transport]
+        info = [self.__class__.__name__, f'transport={self._transport!r}']
        if self._reader is not None:
-            info.append('reader=%r' % self._reader)
-        return '<%s>' % ' '.join(info)
+            info.append(f'reader={self._reader!r}')
+        return '<{}>'.format(' '.join(info))

    @property
    def transport(self):
@@ -305,36 +357,68 @@ class StreamWriter:
    def close(self):
        return self._transport.close()

+    def is_closing(self):
+        return self._transport.is_closing()
+
+    async def wait_closed(self):
+        await self._protocol._get_close_waiter(self)
+
    def get_extra_info(self, name, default=None):
        return self._transport.get_extra_info(name, default)

-    @coroutine
-    def drain(self):
+    async def drain(self):
        """Flush the write buffer.

        The intended use is to write

          w.write(data)
-          yield from w.drain()
+          await w.drain()
        """
        if self._reader is not None:
            exc = self._reader.exception()
            if exc is not None:
                raise exc
-        if self._transport is not None:
-            if self._transport.is_closing():
-                # Yield to the event loop so connection_lost() may be
-                # called.  Without this, _drain_helper() would return
-                # immediately, and code that calls
-                #     write(...); yield from drain()
-                # in a loop would never call connection_lost(), so it
-                # would not see an error when the socket is closed.
-                yield
-        yield from self._protocol._drain_helper()
+        if self._transport.is_closing():
+            # Wait for protocol.connection_lost() call
+            # Raise connection closing error if any,
+            # ConnectionResetError otherwise
+            # Yield to the event loop so connection_lost() may be
+            # called.  Without this, _drain_helper() would return
+            # immediately, and code that calls
+            #     write(...); await drain()
+            # in a loop would never call connection_lost(), so it
+            # would not see an error when the socket is closed.
+            await sleep(0)
+        await self._protocol._drain_helper()

+    async def start_tls(self, sslcontext, *,
+                        server_hostname=None,
+                        ssl_handshake_timeout=None,
+                        ssl_shutdown_timeout=None):
+        """Upgrade an existing stream-based connection to TLS."""
+        server_side = self._protocol._client_connected_cb is not None
+        protocol = self._protocol
+        await self.drain()
+        new_transport = await self._loop.start_tls(  # type: ignore
+            self._transport, protocol, sslcontext,
+            server_side=server_side, server_hostname=server_hostname,
+            ssl_handshake_timeout=ssl_handshake_timeout,
+            ssl_shutdown_timeout=ssl_shutdown_timeout)
+        self._transport = new_transport
+        protocol._replace_writer(self)
+
+    def __del__(self):
+        if not self._transport.is_closing():
+            if self._loop.is_closed():
+                warnings.warn("loop is closed", ResourceWarning)
+            else:
+                self.close()
+                warnings.warn(f"unclosed {self!r}", ResourceWarning)

 class StreamReader:

+    _source_traceback = None
+
    def __init__(self, limit=_DEFAULT_LIMIT, loop=None):
        # The line length limit is  a security feature;
        # it also doubles as half the buffer limit.
@@ -353,24 +437,27 @@ class StreamReader:
        self._exception = None
        self._transport = None
        self._paused = False
+        if self._loop.get_debug():
+            self._source_traceback = format_helpers.extract_stack(
+                sys._getframe(1))

    def __repr__(self):
        info = ['StreamReader']
        if self._buffer:
-            info.append('%d bytes' % len(self._buffer))
+            info.append(f'{len(self._buffer)} bytes')
        if self._eof:
            info.append('eof')
        if self._limit != _DEFAULT_LIMIT:
-            info.append('l=%d' % self._limit)
+            info.append(f'limit={self._limit}')
        if self._waiter:
-            info.append('w=%r' % self._waiter)
+            info.append(f'waiter={self._waiter!r}')
        if self._exception:
-            info.append('e=%r' % self._exception)
+            info.append(f'exception={self._exception!r}')
        if self._transport:
-            info.append('t=%r' % self._transport)
+            info.append(f'transport={self._transport!r}')
        if self._paused:
            info.append('paused')
-        return '<%s>' % ' '.join(info)
+        return '<{}>'.format(' '.join(info))

    def exception(self):
        return self._exception
@@ -431,8 +518,7 @@ class StreamReader:
            else:
                self._paused = True

-    @coroutine
-    def _wait_for_data(self, func_name):
+    async def _wait_for_data(self, func_name):
        """Wait until feed_data() or feed_eof() is called.

        If stream was paused, automatically resume it.
@@ -442,8 +528,9 @@ class StreamReader:
        # would have an unexpected behaviour. It would not possible to know
        # which coroutine would get the next data.
        if self._waiter is not None:
-            raise RuntimeError('%s() called while another coroutine is '
-                               'already waiting for incoming data' % func_name)
+            raise RuntimeError(
+                f'{func_name}() called while another coroutine is '
+                f'already waiting for incoming data')

        assert not self._eof, '_wait_for_data after EOF'

@@ -455,12 +542,11 @@ class StreamReader:

        self._waiter = self._loop.create_future()
        try:
-            yield from self._waiter
+            await self._waiter
        finally:
            self._waiter = None

-    @coroutine
-    def readline(self):
+    async def readline(self):
        """Read chunk of data from the stream until newline (b'\n') is found.

        On success, return chunk that ends with newline. If only partial
@@ -479,10 +565,10 @@ class StreamReader:
        sep = b'\n'
        seplen = len(sep)
        try:
-            line = yield from self.readuntil(sep)
-        except IncompleteReadError as e:
+            line = await self.readuntil(sep)
+        except exceptions.IncompleteReadError as e:
            return e.partial
-        except LimitOverrunError as e:
+        except exceptions.LimitOverrunError as e:
            if self._buffer.startswith(sep, e.consumed):
                del self._buffer[:e.consumed + seplen]
            else:
@@ -491,8 +577,7 @@ class StreamReader:
            raise ValueError(e.args[0])
        return line

-    @coroutine
-    def readuntil(self, separator=b'\n'):
+    async def readuntil(self, separator=b'\n'):
        """Read data from the stream until ``separator`` is found.

        On success, the data and separator will be removed from the
@@ -558,7 +643,7 @@ class StreamReader:
                # see upper comment for explanation.
                offset = buflen + 1 - seplen
                if offset > self._limit:
-                    raise LimitOverrunError(
+                    raise exceptions.LimitOverrunError(
                        'Separator is not found, and chunk exceed the limit',
                        offset)

@@ -569,13 +654,13 @@ class StreamReader:
            if self._eof:
                chunk = bytes(self._buffer)
                self._buffer.clear()
-                raise IncompleteReadError(chunk, None)
+                raise exceptions.IncompleteReadError(chunk, None)

            # _wait_for_data() will resume reading if stream was paused.
-            yield from self._wait_for_data('readuntil')
+            await self._wait_for_data('readuntil')

        if isep > self._limit:
-            raise LimitOverrunError(
+            raise exceptions.LimitOverrunError(
                'Separator is found, but chunk is longer than limit', isep)

        chunk = self._buffer[:isep + seplen]
@@ -583,20 +668,20 @@ class StreamReader:
        self._maybe_resume_transport()
        return bytes(chunk)

-    @coroutine
-    def read(self, n=-1):
+    async def read(self, n=-1):
        """Read up to `n` bytes from the stream.

-        If n is not provided, or set to -1, read until EOF and return all read
-        bytes. If the EOF was received and the internal buffer is empty, return
-        an empty bytes object.
+        If `n` is not provided or set to -1,
+        read until EOF, then return all read bytes.
+        If EOF was received and the internal buffer is empty,
+        return an empty bytes object.

-        If n is zero, return empty bytes object immediately.
+        If `n` is 0, return an empty bytes object immediately.

-        If n is positive, this function try to read `n` bytes, and may return
-        less or equal bytes than requested, but at least one byte. If EOF was
-        received before any byte is read, this function returns empty byte
-        object.
+        If `n` is positive, return at most `n` available bytes
+        as soon as at least 1 byte is available in the internal buffer.
+        If EOF is received before any byte is read, return an empty
+        bytes object.

        Returned value is not limited with limit, configured at stream
        creation.
@@ -618,24 +703,23 @@ class StreamReader:
            # bytes.  So just call self.read(self._limit) until EOF.
            blocks = []
            while True:
-                block = yield from self.read(self._limit)
+                block = await self.read(self._limit)
                if not block:
                    break
                blocks.append(block)
            return b''.join(blocks)

        if not self._buffer and not self._eof:
-            yield from self._wait_for_data('read')
+            await self._wait_for_data('read')

        # This will work right even if buffer is less than n bytes
-        data = bytes(self._buffer[:n])
+        data = bytes(memoryview(self._buffer)[:n])
        del self._buffer[:n]

        self._maybe_resume_transport()
        return data

-    @coroutine
-    def readexactly(self, n):
+    async def readexactly(self, n):
        """Read exactly `n` bytes.

        Raise an IncompleteReadError if EOF is reached before `n` bytes can be
@@ -663,33 +747,24 @@ class StreamReader:
            if self._eof:
                incomplete = bytes(self._buffer)
                self._buffer.clear()
-                raise IncompleteReadError(incomplete, n)
+                raise exceptions.IncompleteReadError(incomplete, n)

-            yield from self._wait_for_data('readexactly')
+            await self._wait_for_data('readexactly')

        if len(self._buffer) == n:
            data = bytes(self._buffer)
            self._buffer.clear()
        else:
-            data = bytes(self._buffer[:n])
+            data = bytes(memoryview(self._buffer)[:n])
            del self._buffer[:n]
        self._maybe_resume_transport()
        return data

-    if compat.PY35:
-        @coroutine
-        def __aiter__(self):
-            return self
+    def __aiter__(self):
+        return self

-        @coroutine
-        def __anext__(self):
-            val = yield from self.readline()
-            if val == b'':
-                raise StopAsyncIteration
-            return val
-
-    if compat.PY352:
-        # In Python 3.5.2 and greater, __aiter__ should return
-        # the asynchronous iterator directly.
-        def __aiter__(self):
-            return self
+    async def __anext__(self):
+        val = await self.readline()
+        if val == b'':
+            raise StopAsyncIteration
+        return val
--- a/Lib/asyncio/subprocess.py
+++ b/Lib/asyncio/subprocess.py
@@ -1,4 +1,4 @@
-__all__ = ['create_subprocess_exec', 'create_subprocess_shell']
+__all__ = 'create_subprocess_exec', 'create_subprocess_shell'

 import subprocess

@@ -6,7 +6,6 @@ from . import events
 from . import protocols
 from . import streams
 from . import tasks
-from .coroutines import coroutine
 from .log import logger


@@ -24,16 +23,19 @@ class SubprocessStreamProtocol(streams.FlowControlMixin,
        self._limit = limit
        self.stdin = self.stdout = self.stderr = None
        self._transport = None
+        self._process_exited = False
+        self._pipe_fds = []
+        self._stdin_closed = self._loop.create_future()

    def __repr__(self):
        info = [self.__class__.__name__]
        if self.stdin is not None:
-            info.append('stdin=%r' % self.stdin)
+            info.append(f'stdin={self.stdin!r}')
        if self.stdout is not None:
-            info.append('stdout=%r' % self.stdout)
+            info.append(f'stdout={self.stdout!r}')
        if self.stderr is not None:
-            info.append('stderr=%r' % self.stderr)
-        return '<%s>' % ' '.join(info)
+            info.append(f'stderr={self.stderr!r}')
+        return '<{}>'.format(' '.join(info))

    def connection_made(self, transport):
        self._transport = transport
@@ -43,12 +45,14 @@ class SubprocessStreamProtocol(streams.FlowControlMixin,
            self.stdout = streams.StreamReader(limit=self._limit,
                                               loop=self._loop)
            self.stdout.set_transport(stdout_transport)
+            self._pipe_fds.append(1)

        stderr_transport = transport.get_pipe_transport(2)
        if stderr_transport is not None:
            self.stderr = streams.StreamReader(limit=self._limit,
                                               loop=self._loop)
            self.stderr.set_transport(stderr_transport)
+            self._pipe_fds.append(2)

        stdin_transport = transport.get_pipe_transport(0)
        if stdin_transport is not None:
@@ -73,6 +77,13 @@ class SubprocessStreamProtocol(streams.FlowControlMixin,
            if pipe is not None:
                pipe.close()
            self.connection_lost(exc)
+            if exc is None:
+                self._stdin_closed.set_result(None)
+            else:
+                self._stdin_closed.set_exception(exc)
+                # Since calling `wait_closed()` is not mandatory,
+                # we shouldn't log the traceback if this is not awaited.
+                self._stdin_closed._log_traceback = False
            return
        if fd == 1:
            reader = self.stdout
@@ -80,15 +91,28 @@ class SubprocessStreamProtocol(streams.FlowControlMixin,
            reader = self.stderr
        else:
            reader = None
-        if reader != None:
+        if reader is not None:
            if exc is None:
                reader.feed_eof()
            else:
                reader.set_exception(exc)

+        if fd in self._pipe_fds:
+            self._pipe_fds.remove(fd)
+        self._maybe_close_transport()
+
    def process_exited(self):
-        self._transport.close()
-        self._transport = None
+        self._process_exited = True
+        self._maybe_close_transport()
+
+    def _maybe_close_transport(self):
+        if len(self._pipe_fds) == 0 and self._process_exited:
+            self._transport.close()
+            self._transport = None
+
+    def _get_close_waiter(self, stream):
+        if stream is self.stdin:
+            return self._stdin_closed


 class Process:
@@ -102,18 +126,15 @@ class Process:
        self.pid = transport.get_pid()

    def __repr__(self):
-        return '<%s %s>' % (self.__class__.__name__, self.pid)
+        return f'<{self.__class__.__name__} {self.pid}>'

    @property
    def returncode(self):
        return self._transport.get_returncode()

-    @coroutine
-    def wait(self):
-        """Wait until the process exit and return the process return code.
-
-        This method is a coroutine."""
-        return (yield from self._transport._wait())
+    async def wait(self):
+        """Wait until the process exit and return the process return code."""
+        return await self._transport._wait()

    def send_signal(self, signal):
        self._transport.send_signal(signal)
@@ -124,17 +145,19 @@ class Process:
    def kill(self):
        self._transport.kill()

-    @coroutine
-    def _feed_stdin(self, input):
+    async def _feed_stdin(self, input):
        debug = self._loop.get_debug()
-        self.stdin.write(input)
-        if debug:
-            logger.debug('%r communicate: feed stdin (%s bytes)',
-                        self, len(input))
        try:
-            yield from self.stdin.drain()
+            if input is not None:
+                self.stdin.write(input)
+                if debug:
+                    logger.debug(
+                        '%r communicate: feed stdin (%s bytes)', self, len(input))
+
+            await self.stdin.drain()
        except (BrokenPipeError, ConnectionResetError) as exc:
-            # communicate() ignores BrokenPipeError and ConnectionResetError
+            # communicate() ignores BrokenPipeError and ConnectionResetError.
+            # write() and drain() can raise these exceptions.
            if debug:
                logger.debug('%r communicate: stdin got %r', self, exc)

@@ -142,12 +165,10 @@ class Process:
            logger.debug('%r communicate: close stdin', self)
        self.stdin.close()

-    @coroutine
-    def _noop(self):
+    async def _noop(self):
        return None

-    @coroutine
-    def _read_stream(self, fd):
+    async def _read_stream(self, fd):
        transport = self._transport.get_pipe_transport(fd)
        if fd == 2:
            stream = self.stderr
@@ -157,16 +178,15 @@ class Process:
        if self._loop.get_debug():
            name = 'stdout' if fd == 1 else 'stderr'
            logger.debug('%r communicate: read %s', self, name)
-        output = yield from stream.read()
+        output = await stream.read()
        if self._loop.get_debug():
            name = 'stdout' if fd == 1 else 'stderr'
            logger.debug('%r communicate: close %s', self, name)
        transport.close()
        return output

-    @coroutine
-    def communicate(self, input=None):
-        if input is not None:
+    async def communicate(self, input=None):
+        if self.stdin is not None:
            stdin = self._feed_stdin(input)
        else:
            stdin = self._noop()
@@ -178,36 +198,32 @@ class Process:
            stderr = self._read_stream(2)
        else:
            stderr = self._noop()
-        stdin, stdout, stderr = yield from tasks.gather(stdin, stdout, stderr,
-                                                        loop=self._loop)
-        yield from self.wait()
+        stdin, stdout, stderr = await tasks.gather(stdin, stdout, stderr)
+        await self.wait()
        return (stdout, stderr)


-@coroutine
-def create_subprocess_shell(cmd, stdin=None, stdout=None, stderr=None,
-                            loop=None, limit=streams._DEFAULT_LIMIT, **kwds):
-    if loop is None:
-        loop = events.get_event_loop()
+async def create_subprocess_shell(cmd, stdin=None, stdout=None, stderr=None,
+                                  limit=streams._DEFAULT_LIMIT, **kwds):
+    loop = events.get_running_loop()
    protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
                                                        loop=loop)
-    transport, protocol = yield from loop.subprocess_shell(
-                                            protocol_factory,
-                                            cmd, stdin=stdin, stdout=stdout,
-                                            stderr=stderr, **kwds)
+    transport, protocol = await loop.subprocess_shell(
+        protocol_factory,
+        cmd, stdin=stdin, stdout=stdout,
+        stderr=stderr, **kwds)
    return Process(transport, protocol, loop)

-@coroutine
-def create_subprocess_exec(program, *args, stdin=None, stdout=None,
-                           stderr=None, loop=None,
-                           limit=streams._DEFAULT_LIMIT, **kwds):
-    if loop is None:
-        loop = events.get_event_loop()
+
+async def create_subprocess_exec(program, *args, stdin=None, stdout=None,
+                                 stderr=None, limit=streams._DEFAULT_LIMIT,
+                                 **kwds):
+    loop = events.get_running_loop()
    protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
                                                        loop=loop)
-    transport, protocol = yield from loop.subprocess_exec(
-                                            protocol_factory,
-                                            program, *args,
-                                            stdin=stdin, stdout=stdout,
-                                            stderr=stderr, **kwds)
+    transport, protocol = await loop.subprocess_exec(
+        protocol_factory,
+        program, *args,
+        stdin=stdin, stdout=stdout,
+        stderr=stderr, **kwds)
    return Process(transport, protocol, loop)
--- a/Lib/asyncio/taskgroups.py
+++ b/Lib/asyncio/taskgroups.py
@@ -0,0 +1,240 @@
+# Adapted with permission from the EdgeDB project;
+# license: PSFL.
+
+
+__all__ = ("TaskGroup",)
+
+from . import events
+from . import exceptions
+from . import tasks
+
+
+class TaskGroup:
+    """Asynchronous context manager for managing groups of tasks.
+
+    Example use:
+
+        async with asyncio.TaskGroup() as group:
+            task1 = group.create_task(some_coroutine(...))
+            task2 = group.create_task(other_coroutine(...))
+        print("Both tasks have completed now.")
+
+    All tasks are awaited when the context manager exits.
+
+    Any exceptions other than `asyncio.CancelledError` raised within
+    a task will cancel all remaining tasks and wait for them to exit.
+    The exceptions are then combined and raised as an `ExceptionGroup`.
+    """
+    def __init__(self):
+        self._entered = False
+        self._exiting = False
+        self._aborting = False
+        self._loop = None
+        self._parent_task = None
+        self._parent_cancel_requested = False
+        self._tasks = set()
+        self._errors = []
+        self._base_error = None
+        self._on_completed_fut = None
+
+    def __repr__(self):
+        info = ['']
+        if self._tasks:
+            info.append(f'tasks={len(self._tasks)}')
+        if self._errors:
+            info.append(f'errors={len(self._errors)}')
+        if self._aborting:
+            info.append('cancelling')
+        elif self._entered:
+            info.append('entered')
+
+        info_str = ' '.join(info)
+        return f'<TaskGroup{info_str}>'
+
+    async def __aenter__(self):
+        if self._entered:
+            raise RuntimeError(
+                f"TaskGroup {self!r} has already been entered")
+        if self._loop is None:
+            self._loop = events.get_running_loop()
+        self._parent_task = tasks.current_task(self._loop)
+        if self._parent_task is None:
+            raise RuntimeError(
+                f'TaskGroup {self!r} cannot determine the parent task')
+        self._entered = True
+
+        return self
+
+    async def __aexit__(self, et, exc, tb):
+        self._exiting = True
+
+        if (exc is not None and
+                self._is_base_error(exc) and
+                self._base_error is None):
+            self._base_error = exc
+
+        propagate_cancellation_error = \
+            exc if et is exceptions.CancelledError else None
+        if self._parent_cancel_requested:
+            # If this flag is set we *must* call uncancel().
+            if self._parent_task.uncancel() == 0:
+                # If there are no pending cancellations left,
+                # don't propagate CancelledError.
+                propagate_cancellation_error = None
+
+        if et is not None:
+            if not self._aborting:
+                # Our parent task is being cancelled:
+                #
+                #    async with TaskGroup() as g:
+                #        g.create_task(...)
+                #        await ...  # <- CancelledError
+                #
+                # or there's an exception in "async with":
+                #
+                #    async with TaskGroup() as g:
+                #        g.create_task(...)
+                #        1 / 0
+                #
+                self._abort()
+
+        # We use while-loop here because "self._on_completed_fut"
+        # can be cancelled multiple times if our parent task
+        # is being cancelled repeatedly (or even once, when
+        # our own cancellation is already in progress)
+        while self._tasks:
+            if self._on_completed_fut is None:
+                self._on_completed_fut = self._loop.create_future()
+
+            try:
+                await self._on_completed_fut
+            except exceptions.CancelledError as ex:
+                if not self._aborting:
+                    # Our parent task is being cancelled:
+                    #
+                    #    async def wrapper():
+                    #        async with TaskGroup() as g:
+                    #            g.create_task(foo)
+                    #
+                    # "wrapper" is being cancelled while "foo" is
+                    # still running.
+                    propagate_cancellation_error = ex
+                    self._abort()
+
+            self._on_completed_fut = None
+
+        assert not self._tasks
+
+        if self._base_error is not None:
+            raise self._base_error
+
+        # Propagate CancelledError if there is one, except if there
+        # are other errors -- those have priority.
+        if propagate_cancellation_error and not self._errors:
+            raise propagate_cancellation_error
+
+        if et is not None and et is not exceptions.CancelledError:
+            self._errors.append(exc)
+
+        if self._errors:
+            # Exceptions are heavy objects that can have object
+            # cycles (bad for GC); let's not keep a reference to
+            # a bunch of them.
+            try:
+                me = BaseExceptionGroup('unhandled errors in a TaskGroup', self._errors)
+                raise me from None
+            finally:
+                self._errors = None
+
+    def create_task(self, coro, *, name=None, context=None):
+        """Create a new task in this group and return it.
+
+        Similar to `asyncio.create_task`.
+        """
+        if not self._entered:
+            raise RuntimeError(f"TaskGroup {self!r} has not been entered")
+        if self._exiting and not self._tasks:
+            raise RuntimeError(f"TaskGroup {self!r} is finished")
+        if self._aborting:
+            raise RuntimeError(f"TaskGroup {self!r} is shutting down")
+        if context is None:
+            task = self._loop.create_task(coro)
+        else:
+            task = self._loop.create_task(coro, context=context)
+        tasks._set_task_name(task, name)
+        # optimization: Immediately call the done callback if the task is
+        # already done (e.g. if the coro was able to complete eagerly),
+        # and skip scheduling a done callback
+        if task.done():
+            self._on_task_done(task)
+        else:
+            self._tasks.add(task)
+            task.add_done_callback(self._on_task_done)
+        return task
+
+    # Since Python 3.8 Tasks propagate all exceptions correctly,
+    # except for KeyboardInterrupt and SystemExit which are
+    # still considered special.
+
+    def _is_base_error(self, exc: BaseException) -> bool:
+        assert isinstance(exc, BaseException)
+        return isinstance(exc, (SystemExit, KeyboardInterrupt))
+
+    def _abort(self):
+        self._aborting = True
+
+        for t in self._tasks:
+            if not t.done():
+                t.cancel()
+
+    def _on_task_done(self, task):
+        self._tasks.discard(task)
+
+        if self._on_completed_fut is not None and not self._tasks:
+            if not self._on_completed_fut.done():
+                self._on_completed_fut.set_result(True)
+
+        if task.cancelled():
+            return
+
+        exc = task.exception()
+        if exc is None:
+            return
+
+        self._errors.append(exc)
+        if self._is_base_error(exc) and self._base_error is None:
+            self._base_error = exc
+
+        if self._parent_task.done():
+            # Not sure if this case is possible, but we want to handle
+            # it anyways.
+            self._loop.call_exception_handler({
+                'message': f'Task {task!r} has errored out but its parent '
+                           f'task {self._parent_task} is already completed',
+                'exception': exc,
+                'task': task,
+            })
+            return
+
+        if not self._aborting and not self._parent_cancel_requested:
+            # If parent task *is not* being cancelled, it means that we want
+            # to manually cancel it to abort whatever is being run right now
+            # in the TaskGroup.  But we want to mark parent task as
+            # "not cancelled" later in __aexit__.  Example situation that
+            # we need to handle:
+            #
+            #    async def foo():
+            #        try:
+            #            async with TaskGroup() as g:
+            #                g.create_task(crash_soon())
+            #                await something  # <- this needs to be canceled
+            #                                 #    by the TaskGroup, e.g.
+            #                                 #    foo() needs to be cancelled
+            #        except Exception:
+            #            # Ignore any exceptions raised in the TaskGroup
+            #            pass
+            #        await something_else     # this line has to be called
+            #                                 # after TaskGroup is finished.
+            self._abort()
+            self._parent_cancel_requested = True
+            self._parent_task.cancel()
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
--- a/Lib/asyncio/test_utils.py
+++ b/Lib/asyncio/test_utils.py
@@ -1,503 +0,0 @@
-"""Utilities shared by tests."""
-
-import collections
-import contextlib
-import io
-import logging
-import os
-import re
-import socket
-import socketserver
-import sys
-import tempfile
-import threading
-import time
-import unittest
-import weakref
-
-from unittest import mock
-
-from http.server import HTTPServer
-from wsgiref.simple_server import WSGIRequestHandler, WSGIServer
-
-try:
-    import ssl
-except ImportError:  # pragma: no cover
-    ssl = None
-
-from . import base_events
-from . import compat
-from . import events
-from . import futures
-from . import selectors
-from . import tasks
-from .coroutines import coroutine
-from .log import logger
-
-
-if sys.platform == 'win32':  # pragma: no cover
-    from .windows_utils import socketpair
-else:
-    from socket import socketpair  # pragma: no cover
-
-
-def dummy_ssl_context():
-    if ssl is None:
-        return None
-    else:
-        return ssl.SSLContext(ssl.PROTOCOL_SSLv23)
-
-
-def run_briefly(loop):
-    @coroutine
-    def once():
-        pass
-    gen = once()
-    t = loop.create_task(gen)
-    # Don't log a warning if the task is not done after run_until_complete().
-    # It occurs if the loop is stopped or if a task raises a BaseException.
-    t._log_destroy_pending = False
-    try:
-        loop.run_until_complete(t)
-    finally:
-        gen.close()
-
-
-def run_until(loop, pred, timeout=30):
-    deadline = time.time() + timeout
-    while not pred():
-        if timeout is not None:
-            timeout = deadline - time.time()
-            if timeout <= 0:
-                raise futures.TimeoutError()
-        loop.run_until_complete(tasks.sleep(0.001, loop=loop))
-
-
-def run_once(loop):
-    """Legacy API to run once through the event loop.
-
-    This is the recommended pattern for test code.  It will poll the
-    selector once and run all callbacks scheduled in response to I/O
-    events.
-    """
-    loop.call_soon(loop.stop)
-    loop.run_forever()
-
-
-class SilentWSGIRequestHandler(WSGIRequestHandler):
-
-    def get_stderr(self):
-        return io.StringIO()
-
-    def log_message(self, format, *args):
-        pass
-
-
-class SilentWSGIServer(WSGIServer):
-
-    request_timeout = 2
-
-    def get_request(self):
-        request, client_addr = super().get_request()
-        request.settimeout(self.request_timeout)
-        return request, client_addr
-
-    def handle_error(self, request, client_address):
-        pass
-
-
-class SSLWSGIServerMixin:
-
-    def finish_request(self, request, client_address):
-        # The relative location of our test directory (which
-        # contains the ssl key and certificate files) differs
-        # between the stdlib and stand-alone asyncio.
-        # Prefer our own if we can find it.
-        here = os.path.join(os.path.dirname(__file__), '..', 'tests')
-        if not os.path.isdir(here):
-            here = os.path.join(os.path.dirname(os.__file__),
-                                'test', 'test_asyncio')
-        keyfile = os.path.join(here, 'ssl_key.pem')
-        certfile = os.path.join(here, 'ssl_cert.pem')
-        context = ssl.SSLContext()
-        context.load_cert_chain(certfile, keyfile)
-
-        ssock = context.wrap_socket(request, server_side=True)
-        try:
-            self.RequestHandlerClass(ssock, client_address, self)
-            ssock.close()
-        except OSError:
-            # maybe socket has been closed by peer
-            pass
-
-
-class SSLWSGIServer(SSLWSGIServerMixin, SilentWSGIServer):
-    pass
-
-
-def _run_test_server(*, address, use_ssl=False, server_cls, server_ssl_cls):
-
-    def app(environ, start_response):
-        status = '200 OK'
-        headers = [('Content-type', 'text/plain')]
-        start_response(status, headers)
-        return [b'Test message']
-
-    # Run the test WSGI server in a separate thread in order not to
-    # interfere with event handling in the main thread
-    server_class = server_ssl_cls if use_ssl else server_cls
-    httpd = server_class(address, SilentWSGIRequestHandler)
-    httpd.set_app(app)
-    httpd.address = httpd.server_address
-    server_thread = threading.Thread(
-        target=lambda: httpd.serve_forever(poll_interval=0.05))
-    server_thread.start()
-    try:
-        yield httpd
-    finally:
-        httpd.shutdown()
-        httpd.server_close()
-        server_thread.join()
-
-
-if hasattr(socket, 'AF_UNIX'):
-
-    class UnixHTTPServer(socketserver.UnixStreamServer, HTTPServer):
-
-        def server_bind(self):
-            socketserver.UnixStreamServer.server_bind(self)
-            self.server_name = '127.0.0.1'
-            self.server_port = 80
-
-
-    class UnixWSGIServer(UnixHTTPServer, WSGIServer):
-
-        request_timeout = 2
-
-        def server_bind(self):
-            UnixHTTPServer.server_bind(self)
-            self.setup_environ()
-
-        def get_request(self):
-            request, client_addr = super().get_request()
-            request.settimeout(self.request_timeout)
-            # Code in the stdlib expects that get_request
-            # will return a socket and a tuple (host, port).
-            # However, this isn't true for UNIX sockets,
-            # as the second return value will be a path;
-            # hence we return some fake data sufficient
-            # to get the tests going
-            return request, ('127.0.0.1', '')
-
-
-    class SilentUnixWSGIServer(UnixWSGIServer):
-
-        def handle_error(self, request, client_address):
-            pass
-
-
-    class UnixSSLWSGIServer(SSLWSGIServerMixin, SilentUnixWSGIServer):
-        pass
-
-
-    def gen_unix_socket_path():
-        with tempfile.NamedTemporaryFile() as file:
-            return file.name
-
-
-    @contextlib.contextmanager
-    def unix_socket_path():
-        path = gen_unix_socket_path()
-        try:
-            yield path
-        finally:
-            try:
-                os.unlink(path)
-            except OSError:
-                pass
-
-
-    @contextlib.contextmanager
-    def run_test_unix_server(*, use_ssl=False):
-        with unix_socket_path() as path:
-            yield from _run_test_server(address=path, use_ssl=use_ssl,
-                                        server_cls=SilentUnixWSGIServer,
-                                        server_ssl_cls=UnixSSLWSGIServer)
-
-
-@contextlib.contextmanager
-def run_test_server(*, host='127.0.0.1', port=0, use_ssl=False):
-    yield from _run_test_server(address=(host, port), use_ssl=use_ssl,
-                                server_cls=SilentWSGIServer,
-                                server_ssl_cls=SSLWSGIServer)
-
-
-def make_test_protocol(base):
-    dct = {}
-    for name in dir(base):
-        if name.startswith('__') and name.endswith('__'):
-            # skip magic names
-            continue
-        dct[name] = MockCallback(return_value=None)
-    return type('TestProtocol', (base,) + base.__bases__, dct)()
-
-
-class TestSelector(selectors.BaseSelector):
-
-    def __init__(self):
-        self.keys = {}
-
-    def register(self, fileobj, events, data=None):
-        key = selectors.SelectorKey(fileobj, 0, events, data)
-        self.keys[fileobj] = key
-        return key
-
-    def unregister(self, fileobj):
-        return self.keys.pop(fileobj)
-
-    def select(self, timeout):
-        return []
-
-    def get_map(self):
-        return self.keys
-
-
-class TestLoop(base_events.BaseEventLoop):
-    """Loop for unittests.
-
-    It manages self time directly.
-    If something scheduled to be executed later then
-    on next loop iteration after all ready handlers done
-    generator passed to __init__ is calling.
-
-    Generator should be like this:
-
-        def gen():
-            ...
-            when = yield ...
-            ... = yield time_advance
-
-    Value returned by yield is absolute time of next scheduled handler.
-    Value passed to yield is time advance to move loop's time forward.
-    """
-
-    def __init__(self, gen=None):
-        super().__init__()
-
-        if gen is None:
-            def gen():
-                yield
-            self._check_on_close = False
-        else:
-            self._check_on_close = True
-
-        self._gen = gen()
-        next(self._gen)
-        self._time = 0
-        self._clock_resolution = 1e-9
-        self._timers = []
-        self._selector = TestSelector()
-
-        self.readers = {}
-        self.writers = {}
-        self.reset_counters()
-
-        self._transports = weakref.WeakValueDictionary()
-
-    def time(self):
-        return self._time
-
-    def advance_time(self, advance):
-        """Move test time forward."""
-        if advance:
-            self._time += advance
-
-    def close(self):
-        super().close()
-        if self._check_on_close:
-            try:
-                self._gen.send(0)
-            except StopIteration:
-                pass
-            else:  # pragma: no cover
-                raise AssertionError("Time generator is not finished")
-
-    def _add_reader(self, fd, callback, *args):
-        self.readers[fd] = events.Handle(callback, args, self)
-
-    def _remove_reader(self, fd):
-        self.remove_reader_count[fd] += 1
-        if fd in self.readers:
-            del self.readers[fd]
-            return True
-        else:
-            return False
-
-    def assert_reader(self, fd, callback, *args):
-        assert fd in self.readers, 'fd {} is not registered'.format(fd)
-        handle = self.readers[fd]
-        assert handle._callback == callback, '{!r} != {!r}'.format(
-            handle._callback, callback)
-        assert handle._args == args, '{!r} != {!r}'.format(
-            handle._args, args)
-
-    def _add_writer(self, fd, callback, *args):
-        self.writers[fd] = events.Handle(callback, args, self)
-
-    def _remove_writer(self, fd):
-        self.remove_writer_count[fd] += 1
-        if fd in self.writers:
-            del self.writers[fd]
-            return True
-        else:
-            return False
-
-    def assert_writer(self, fd, callback, *args):
-        assert fd in self.writers, 'fd {} is not registered'.format(fd)
-        handle = self.writers[fd]
-        assert handle._callback == callback, '{!r} != {!r}'.format(
-            handle._callback, callback)
-        assert handle._args == args, '{!r} != {!r}'.format(
-            handle._args, args)
-
-    def _ensure_fd_no_transport(self, fd):
-        try:
-            transport = self._transports[fd]
-        except KeyError:
-            pass
-        else:
-            raise RuntimeError(
-                'File descriptor {!r} is used by transport {!r}'.format(
-                    fd, transport))
-
-    def add_reader(self, fd, callback, *args):
-        """Add a reader callback."""
-        self._ensure_fd_no_transport(fd)
-        return self._add_reader(fd, callback, *args)
-
-    def remove_reader(self, fd):
-        """Remove a reader callback."""
-        self._ensure_fd_no_transport(fd)
-        return self._remove_reader(fd)
-
-    def add_writer(self, fd, callback, *args):
-        """Add a writer callback.."""
-        self._ensure_fd_no_transport(fd)
-        return self._add_writer(fd, callback, *args)
-
-    def remove_writer(self, fd):
-        """Remove a writer callback."""
-        self._ensure_fd_no_transport(fd)
-        return self._remove_writer(fd)
-
-    def reset_counters(self):
-        self.remove_reader_count = collections.defaultdict(int)
-        self.remove_writer_count = collections.defaultdict(int)
-
-    def _run_once(self):
-        super()._run_once()
-        for when in self._timers:
-            advance = self._gen.send(when)
-            self.advance_time(advance)
-        self._timers = []
-
-    def call_at(self, when, callback, *args):
-        self._timers.append(when)
-        return super().call_at(when, callback, *args)
-
-    def _process_events(self, event_list):
-        return
-
-    def _write_to_self(self):
-        pass
-
-
-def MockCallback(**kwargs):
-    return mock.Mock(spec=['__call__'], **kwargs)
-
-
-class MockPattern(str):
-    """A regex based str with a fuzzy __eq__.
-
-    Use this helper with 'mock.assert_called_with', or anywhere
-    where a regex comparison between strings is needed.
-
-    For instance:
-       mock_call.assert_called_with(MockPattern('spam.*ham'))
-    """
-    def __eq__(self, other):
-        return bool(re.search(str(self), other, re.S))
-
-
-def get_function_source(func):
-    source = events._get_function_source(func)
-    if source is None:
-        raise ValueError("unable to get the source of %r" % (func,))
-    return source
-
-
-class TestCase(unittest.TestCase):
-    def set_event_loop(self, loop, *, cleanup=True):
-        assert loop is not None
-        # ensure that the event loop is passed explicitly in asyncio
-        events.set_event_loop(None)
-        if cleanup:
-            self.addCleanup(loop.close)
-
-    def new_test_loop(self, gen=None):
-        loop = TestLoop(gen)
-        self.set_event_loop(loop)
-        return loop
-
-    def setUp(self):
-        self._get_running_loop = events._get_running_loop
-        events._get_running_loop = lambda: None
-
-    def tearDown(self):
-        events._get_running_loop = self._get_running_loop
-
-        events.set_event_loop(None)
-
-        # Detect CPython bug #23353: ensure that yield/yield-from is not used
-        # in an except block of a generator
-        self.assertEqual(sys.exc_info(), (None, None, None))
-
-    if not compat.PY34:
-        # Python 3.3 compatibility
-        def subTest(self, *args, **kwargs):
-            class EmptyCM:
-                def __enter__(self):
-                    pass
-                def __exit__(self, *exc):
-                    pass
-            return EmptyCM()
-
-
-@contextlib.contextmanager
-def disable_logger():
-    """Context manager to disable asyncio logger.
-
-    For example, it can be used to ignore warnings in debug mode.
-    """
-    old_level = logger.level
-    try:
-        logger.setLevel(logging.CRITICAL+1)
-        yield
-    finally:
-        logger.setLevel(old_level)
-
-
-def mock_nonblocking_socket(proto=socket.IPPROTO_TCP, type=socket.SOCK_STREAM,
-                            family=socket.AF_INET):
-    """Create a mock of a non-blocking socket."""
-    sock = mock.MagicMock(socket.socket)
-    sock.proto = proto
-    sock.type = type
-    sock.family = family
-    sock.gettimeout.return_value = 0.0
-    return sock
-
-
-def force_legacy_ssl_support():
-    return mock.patch('asyncio.sslproto._is_sslproto_available',
-                      return_value=False)
--- a/Lib/asyncio/threads.py
+++ b/Lib/asyncio/threads.py
@@ -0,0 +1,25 @@
+"""High-level support for working with threads in asyncio"""
+
+import functools
+import contextvars
+
+from . import events
+
+
+__all__ = "to_thread",
+
+
+async def to_thread(func, /, *args, **kwargs):
+    """Asynchronously run function *func* in a separate thread.
+
+    Any *args and **kwargs supplied for this function are directly passed
+    to *func*. Also, the current :class:`contextvars.Context` is propagated,
+    allowing context variables from the main thread to be accessed in the
+    separate thread.
+
+    Return a coroutine that can be awaited to get the eventual result of *func*.
+    """
+    loop = events.get_running_loop()
+    ctx = contextvars.copy_context()
+    func_call = functools.partial(ctx.run, func, *args, **kwargs)
+    return await loop.run_in_executor(None, func_call)
--- a/Lib/asyncio/timeouts.py
+++ b/Lib/asyncio/timeouts.py
@@ -0,0 +1,168 @@
+import enum
+
+from types import TracebackType
+from typing import final, Optional, Type
+
+from . import events
+from . import exceptions
+from . import tasks
+
+
+__all__ = (
+    "Timeout",
+    "timeout",
+    "timeout_at",
+)
+
+
+class _State(enum.Enum):
+    CREATED = "created"
+    ENTERED = "active"
+    EXPIRING = "expiring"
+    EXPIRED = "expired"
+    EXITED = "finished"
+
+
+@final
+class Timeout:
+    """Asynchronous context manager for cancelling overdue coroutines.
+
+    Use `timeout()` or `timeout_at()` rather than instantiating this class directly.
+    """
+
+    def __init__(self, when: Optional[float]) -> None:
+        """Schedule a timeout that will trigger at a given loop time.
+
+        - If `when` is `None`, the timeout will never trigger.
+        - If `when < loop.time()`, the timeout will trigger on the next
+          iteration of the event loop.
+        """
+        self._state = _State.CREATED
+
+        self._timeout_handler: Optional[events.TimerHandle] = None
+        self._task: Optional[tasks.Task] = None
+        self._when = when
+
+    def when(self) -> Optional[float]:
+        """Return the current deadline."""
+        return self._when
+
+    def reschedule(self, when: Optional[float]) -> None:
+        """Reschedule the timeout."""
+        if self._state is not _State.ENTERED:
+            if self._state is _State.CREATED:
+                raise RuntimeError("Timeout has not been entered")
+            raise RuntimeError(
+                f"Cannot change state of {self._state.value} Timeout",
+            )
+
+        self._when = when
+
+        if self._timeout_handler is not None:
+            self._timeout_handler.cancel()
+
+        if when is None:
+            self._timeout_handler = None
+        else:
+            loop = events.get_running_loop()
+            if when <= loop.time():
+                self._timeout_handler = loop.call_soon(self._on_timeout)
+            else:
+                self._timeout_handler = loop.call_at(when, self._on_timeout)
+
+    def expired(self) -> bool:
+        """Is timeout expired during execution?"""
+        return self._state in (_State.EXPIRING, _State.EXPIRED)
+
+    def __repr__(self) -> str:
+        info = ['']
+        if self._state is _State.ENTERED:
+            when = round(self._when, 3) if self._when is not None else None
+            info.append(f"when={when}")
+        info_str = ' '.join(info)
+        return f"<Timeout [{self._state.value}]{info_str}>"
+
+    async def __aenter__(self) -> "Timeout":
+        if self._state is not _State.CREATED:
+            raise RuntimeError("Timeout has already been entered")
+        task = tasks.current_task()
+        if task is None:
+            raise RuntimeError("Timeout should be used inside a task")
+        self._state = _State.ENTERED
+        self._task = task
+        self._cancelling = self._task.cancelling()
+        self.reschedule(self._when)
+        return self
+
+    async def __aexit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_val: Optional[BaseException],
+        exc_tb: Optional[TracebackType],
+    ) -> Optional[bool]:
+        assert self._state in (_State.ENTERED, _State.EXPIRING)
+
+        if self._timeout_handler is not None:
+            self._timeout_handler.cancel()
+            self._timeout_handler = None
+
+        if self._state is _State.EXPIRING:
+            self._state = _State.EXPIRED
+
+            if self._task.uncancel() <= self._cancelling and exc_type is exceptions.CancelledError:
+                # Since there are no new cancel requests, we're
+                # handling this.
+                raise TimeoutError from exc_val
+        elif self._state is _State.ENTERED:
+            self._state = _State.EXITED
+
+        return None
+
+    def _on_timeout(self) -> None:
+        assert self._state is _State.ENTERED
+        self._task.cancel()
+        self._state = _State.EXPIRING
+        # drop the reference early
+        self._timeout_handler = None
+
+
+def timeout(delay: Optional[float]) -> Timeout:
+    """Timeout async context manager.
+
+    Useful in cases when you want to apply timeout logic around block
+    of code or in cases when asyncio.wait_for is not suitable. For example:
+
+    >>> async with asyncio.timeout(10):  # 10 seconds timeout
+    ...     await long_running_task()
+
+
+    delay - value in seconds or None to disable timeout logic
+
+    long_running_task() is interrupted by raising asyncio.CancelledError,
+    the top-most affected timeout() context manager converts CancelledError
+    into TimeoutError.
+    """
+    loop = events.get_running_loop()
+    return Timeout(loop.time() + delay if delay is not None else None)
+
+
+def timeout_at(when: Optional[float]) -> Timeout:
+    """Schedule the timeout at absolute time.
+
+    Like timeout() but argument gives absolute time in the same clock system
+    as loop.time().
+
+    Please note: it is not POSIX time but a time with
+    undefined starting base, e.g. the time of the system power on.
+
+    >>> async with asyncio.timeout_at(loop.time() + 10):
+    ...     await long_running_task()
+
+
+    when - a deadline when timeout occurs or None to disable timeout logic
+
+    long_running_task() is interrupted by raising asyncio.CancelledError,
+    the top-most affected timeout() context manager converts CancelledError
+    into TimeoutError.
+    """
+    return Timeout(when)
--- a/Lib/asyncio/transports.py
+++ b/Lib/asyncio/transports.py
@@ -1,15 +1,16 @@
 """Abstract Transport class."""

-from asyncio import compat
-
-__all__ = ['BaseTransport', 'ReadTransport', 'WriteTransport',
-           'Transport', 'DatagramTransport', 'SubprocessTransport',
-           ]
+__all__ = (
+    'BaseTransport', 'ReadTransport', 'WriteTransport',
+    'Transport', 'DatagramTransport', 'SubprocessTransport',
+)


 class BaseTransport:
    """Base class for transports."""

+    __slots__ = ('_extra',)
+
    def __init__(self, extra=None):
        if extra is None:
            extra = {}
@@ -28,8 +29,8 @@ class BaseTransport:

        Buffered data will be flushed asynchronously.  No more data
        will be received.  After all buffered data is flushed, the
-        protocol's connection_lost() method will (eventually) called
-        with None as its argument.
+        protocol's connection_lost() method will (eventually) be
+        called with None as its argument.
        """
        raise NotImplementedError

@@ -45,6 +46,12 @@ class BaseTransport:
 class ReadTransport(BaseTransport):
    """Interface for read-only transports."""

+    __slots__ = ()
+
+    def is_reading(self):
+        """Return True if the transport is receiving."""
+        raise NotImplementedError
+
    def pause_reading(self):
        """Pause the receiving end.

@@ -65,6 +72,8 @@ class ReadTransport(BaseTransport):
 class WriteTransport(BaseTransport):
    """Interface for write-only transports."""

+    __slots__ = ()
+
    def set_write_buffer_limits(self, high=None, low=None):
        """Set the high- and low-water limits for write flow control.

@@ -90,6 +99,12 @@ class WriteTransport(BaseTransport):
        """Return the current size of the write buffer."""
        raise NotImplementedError

+    def get_write_buffer_limits(self):
+        """Get the high and low watermarks for write flow control.
+        Return a tuple (low, high) where low and high are
+        positive number of bytes."""
+        raise NotImplementedError
+
    def write(self, data):
        """Write some data bytes to the transport.

@@ -104,7 +119,7 @@ class WriteTransport(BaseTransport):
        The default implementation concatenates the arguments and
        calls write() on the result.
        """
-        data = compat.flatten_list_bytes(list_of_data)
+        data = b''.join(list_of_data)
        self.write(data)

    def write_eof(self):
@@ -151,10 +166,14 @@ class Transport(ReadTransport, WriteTransport):
    except writelines(), which calls write() in a loop.
    """

+    __slots__ = ()
+

 class DatagramTransport(BaseTransport):
    """Interface for datagram (UDP) transports."""

+    __slots__ = ()
+
    def sendto(self, data, addr=None):
        """Send data to the transport.

@@ -177,6 +196,8 @@ class DatagramTransport(BaseTransport):

 class SubprocessTransport(BaseTransport):

+    __slots__ = ()
+
    def get_pid(self):
        """Get subprocess id."""
        raise NotImplementedError
@@ -244,6 +265,8 @@ class _FlowControlMixin(Transport):
    resume_writing() may be called.
    """

+    __slots__ = ('_loop', '_protocol_paused', '_high_water', '_low_water')
+
    def __init__(self, extra=None, loop=None):
        super().__init__(extra)
        assert loop is not None
@@ -259,7 +282,9 @@ class _FlowControlMixin(Transport):
            self._protocol_paused = True
            try:
                self._protocol.pause_writing()
-            except Exception as exc:
+            except (SystemExit, KeyboardInterrupt):
+                raise
+            except BaseException as exc:
                self._loop.call_exception_handler({
                    'message': 'protocol.pause_writing() failed',
                    'exception': exc,
@@ -269,11 +294,13 @@ class _FlowControlMixin(Transport):

    def _maybe_resume_protocol(self):
        if (self._protocol_paused and
-            self.get_write_buffer_size() <= self._low_water):
+                self.get_write_buffer_size() <= self._low_water):
            self._protocol_paused = False
            try:
                self._protocol.resume_writing()
-            except Exception as exc:
+            except (SystemExit, KeyboardInterrupt):
+                raise
+            except BaseException as exc:
                self._loop.call_exception_handler({
                    'message': 'protocol.resume_writing() failed',
                    'exception': exc,
@@ -287,14 +314,16 @@ class _FlowControlMixin(Transport):
    def _set_write_buffer_limits(self, high=None, low=None):
        if high is None:
            if low is None:
-                high = 64*1024
+                high = 64 * 1024
            else:
-                high = 4*low
+                high = 4 * low
        if low is None:
            low = high // 4
+
        if not high >= low >= 0:
-            raise ValueError('high (%r) must be >= low (%r) must be >= 0' %
-                             (high, low))
+            raise ValueError(
+                f'high ({high!r}) must be >= low ({low!r}) must be >= 0')
+
        self._high_water = high
        self._low_water = low

--- a/Lib/asyncio/trsock.py
+++ b/Lib/asyncio/trsock.py
@@ -0,0 +1,98 @@
+import socket
+
+
+class TransportSocket:
+
+    """A socket-like wrapper for exposing real transport sockets.
+
+    These objects can be safely returned by APIs like
+    `transport.get_extra_info('socket')`.  All potentially disruptive
+    operations (like "socket.close()") are banned.
+    """
+
+    __slots__ = ('_sock',)
+
+    def __init__(self, sock: socket.socket):
+        self._sock = sock
+
+    @property
+    def family(self):
+        return self._sock.family
+
+    @property
+    def type(self):
+        return self._sock.type
+
+    @property
+    def proto(self):
+        return self._sock.proto
+
+    def __repr__(self):
+        s = (
+            f"<asyncio.TransportSocket fd={self.fileno()}, "
+            f"family={self.family!s}, type={self.type!s}, "
+            f"proto={self.proto}"
+        )
+
+        if self.fileno() != -1:
+            try:
+                laddr = self.getsockname()
+                if laddr:
+                    s = f"{s}, laddr={laddr}"
+            except socket.error:
+                pass
+            try:
+                raddr = self.getpeername()
+                if raddr:
+                    s = f"{s}, raddr={raddr}"
+            except socket.error:
+                pass
+
+        return f"{s}>"
+
+    def __getstate__(self):
+        raise TypeError("Cannot serialize asyncio.TransportSocket object")
+
+    def fileno(self):
+        return self._sock.fileno()
+
+    def dup(self):
+        return self._sock.dup()
+
+    def get_inheritable(self):
+        return self._sock.get_inheritable()
+
+    def shutdown(self, how):
+        # asyncio doesn't currently provide a high-level transport API
+        # to shutdown the connection.
+        self._sock.shutdown(how)
+
+    def getsockopt(self, *args, **kwargs):
+        return self._sock.getsockopt(*args, **kwargs)
+
+    def setsockopt(self, *args, **kwargs):
+        self._sock.setsockopt(*args, **kwargs)
+
+    def getpeername(self):
+        return self._sock.getpeername()
+
+    def getsockname(self):
+        return self._sock.getsockname()
+
+    def getsockbyname(self):
+        return self._sock.getsockbyname()
+
+    def settimeout(self, value):
+        if value == 0:
+            return
+        raise ValueError(
+            'settimeout(): only 0 timeout is allowed on transport sockets')
+
+    def gettimeout(self):
+        return 0
+
+    def setblocking(self, flag):
+        if not flag:
+            return
+        raise ValueError(
+            'setblocking(): transport sockets cannot be blocking')
--- a/Lib/asyncio/unix_events.py
+++ b/Lib/asyncio/unix_events.py
--- a/Show More
+++ b/Show More