Upgrade cmd module from CPython v3.14.2 (#6853)

Upgrades the `cmd` module and its tests from CPython v3.14.2 tag.

Lib/cmd.py

@@ -5,16 +5,16 @@ Interpreters constructed with this class obey the following conventions:
 1. End of file on input is processed as the command 'EOF'.
 2. A command is parsed out of each line by collecting the prefix composed
    of characters in the identchars member.
-3. A command `foo' is dispatched to a method 'do_foo()'; the do_ method
+3. A command 'foo' is dispatched to a method 'do_foo()'; the do_ method
    is passed a single argument consisting of the remainder of the line.
 4. Typing an empty line repeats the last command.  (Actually, it calls the
-   method `emptyline', which may be overridden in a subclass.)
-5. There is a predefined `help' method.  Given an argument `topic', it
-   calls the command `help_topic'.  With no arguments, it lists all topics
+   method 'emptyline', which may be overridden in a subclass.)
+5. There is a predefined 'help' method.  Given an argument 'topic', it
+   calls the command 'help_topic'.  With no arguments, it lists all topics
    with defined help_ functions, broken into up to three topics; documented
    commands, miscellaneous help topics, and undocumented commands.
-6. The command '?' is a synonym for `help'.  The command '!' is a synonym
-   for `shell', if a do_shell method exists.
+6. The command '?' is a synonym for 'help'.  The command '!' is a synonym
+   for 'shell', if a do_shell method exists.
 7. If completion is enabled, completing commands will be done automatically,
    and completing of commands args is done by calling complete_foo() with
    arguments text, line, begidx, endidx.  text is string we are matching
@@ -23,31 +23,34 @@ Interpreters constructed with this class obey the following conventions:
    indexes of the text being matched, which could be used to provide
    different completion depending upon which position the argument is in.
 
-The `default' method may be overridden to intercept commands for which there
+The 'default' method may be overridden to intercept commands for which there
 is no do_ method.
 
-The `completedefault' method may be overridden to intercept completions for
+The 'completedefault' method may be overridden to intercept completions for
 commands that have no complete_ method.
 
-The data member `self.ruler' sets the character used to draw separator lines
+The data member 'self.ruler' sets the character used to draw separator lines
 in the help messages.  If empty, no ruler line is drawn.  It defaults to "=".
 
-If the value of `self.intro' is nonempty when the cmdloop method is called,
+If the value of 'self.intro' is nonempty when the cmdloop method is called,
 it is printed out on interpreter startup.  This value may be overridden
 via an optional argument to the cmdloop() method.
 
-The data members `self.doc_header', `self.misc_header', and
-`self.undoc_header' set the headers used for the help function's
+The data members 'self.doc_header', 'self.misc_header', and
+'self.undoc_header' set the headers used for the help function's
 listings of documented functions, miscellaneous topics, and undocumented
 functions respectively.
 """
 
-import inspect, string, sys
+import sys
 
 __all__ = ["Cmd"]
 
 PROMPT = '(Cmd) '
-IDENTCHARS = string.ascii_letters + string.digits + '_'
+IDENTCHARS = ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+              'abcdefghijklmnopqrstuvwxyz'
+              '0123456789'
+              '_')
 
 class Cmd:
     """A simple framework for writing line-oriented command interpreters.
@@ -270,7 +273,7 @@ class Cmd:
             endidx = readline.get_endidx() - stripped
             if begidx>0:
                 cmd, args, foo = self.parseline(line)
-                if cmd == '':
+                if not cmd:
                     compfunc = self.completedefault
                 else:
                     try:
@@ -303,9 +306,11 @@ class Cmd:
             try:
                 func = getattr(self, 'help_' + arg)
             except AttributeError:
+                from inspect import cleandoc
+
                 try:
                     doc=getattr(self, 'do_' + arg).__doc__
-                    doc = inspect.cleandoc(doc)
+                    doc = cleandoc(doc)
                     if doc:
                         self.stdout.write("%s\n"%str(doc))
                         return

Lib/test/test_cmd.py

@@ -11,9 +11,15 @@ import unittest
 import io
 import textwrap
 from test import support
-from test.support.import_helper import import_module
+from test.support.import_helper import ensure_lazy_imports, import_module
 from test.support.pty_helper import run_pty
 
+class LazyImportTest(unittest.TestCase):
+    @support.cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("cmd", {"inspect", "string"})
+
+
 class samplecmdclass(cmd.Cmd):
     """
     Instance the sampleclass:
@@ -289,6 +295,30 @@ class CmdTestReadline(unittest.TestCase):
         self.assertIn(b'ab_completion_test', output)
         self.assertIn(b'tab completion success', output)
 
+    def test_bang_completion_without_do_shell(self):
+        script = textwrap.dedent("""
+            import cmd
+            class simplecmd(cmd.Cmd):
+                def completedefault(self, text, line, begidx, endidx):
+                    return ["hello"]
+
+                def default(self, line):
+                    if line.replace(" ", "") == "!hello":
+                        print('tab completion success')
+                    else:
+                        print('tab completion failure')
+                    return True
+
+            simplecmd().cmdloop()
+        """)
+
+        # '! h' or '!h' and complete 'ello' to 'hello'
+        for input in [b"! h\t\n", b"!h\t\n"]:
+            with self.subTest(input=input):
+                output = run_pty(script, input)
+                self.assertIn(b'hello', output)
+                self.assertIn(b'tab completion success', output)
+
 def load_tests(loader, tests, pattern):
     tests.addTest(doctest.DocTestSuite())
     return tests