mirror of
https://github.com/RustPython/RustPython.git
synced 2026-06-02 19:39:49 +09:00
98 lines
3.5 KiB
Python
98 lines
3.5 KiB
Python
"""Utility code for constructing importers, etc."""
|
|
from _frozen_importlib import _resolve_name
|
|
from _frozen_importlib import _find_spec
|
|
|
|
import sys
|
|
|
|
|
|
def resolve_name(name, package):
|
|
"""Resolve a relative module name to an absolute one."""
|
|
if not name.startswith('.'):
|
|
return name
|
|
elif not package:
|
|
raise ValueError(f'no package specified for {repr(name)} '
|
|
'(required for relative module names)')
|
|
level = 0
|
|
for character in name:
|
|
if character != '.':
|
|
break
|
|
level += 1
|
|
return _resolve_name(name[level:], package, level)
|
|
|
|
|
|
def _find_spec_from_path(name, path=None):
|
|
"""Return the spec for the specified module.
|
|
|
|
First, sys.modules is checked to see if the module was already imported. If
|
|
so, then sys.modules[name].__spec__ is returned. If that happens to be
|
|
set to None, then ValueError is raised. If the module is not in
|
|
sys.modules, then sys.meta_path is searched for a suitable spec with the
|
|
value of 'path' given to the finders. None is returned if no spec could
|
|
be found.
|
|
|
|
Dotted names do not have their parent packages implicitly imported. You will
|
|
most likely need to explicitly import all parent packages in the proper
|
|
order for a submodule to get the correct spec.
|
|
|
|
"""
|
|
if name not in sys.modules:
|
|
return _find_spec(name, path)
|
|
else:
|
|
module = sys.modules[name]
|
|
if module is None:
|
|
return None
|
|
try:
|
|
spec = module.__spec__
|
|
except AttributeError:
|
|
raise ValueError('{}.__spec__ is not set'.format(name)) from None
|
|
else:
|
|
if spec is None:
|
|
raise ValueError('{}.__spec__ is None'.format(name))
|
|
return spec
|
|
|
|
|
|
def find_spec(name, package=None):
|
|
"""Return the spec for the specified module.
|
|
|
|
First, sys.modules is checked to see if the module was already imported. If
|
|
so, then sys.modules[name].__spec__ is returned. If that happens to be
|
|
set to None, then ValueError is raised. If the module is not in
|
|
sys.modules, then sys.meta_path is searched for a suitable spec with the
|
|
value of 'path' given to the finders. None is returned if no spec could
|
|
be found.
|
|
|
|
If the name is for submodule (contains a dot), the parent module is
|
|
automatically imported.
|
|
|
|
The name and package arguments work the same as importlib.import_module().
|
|
In other words, relative module names (with leading dots) work.
|
|
|
|
"""
|
|
fullname = resolve_name(name, package) if name.startswith('.') else name
|
|
if fullname not in sys.modules:
|
|
parent_name = fullname.rpartition('.')[0]
|
|
if parent_name:
|
|
parent = __import__(parent_name, fromlist=['__path__'])
|
|
try:
|
|
parent_path = parent.__path__
|
|
except AttributeError as e:
|
|
raise ModuleNotFoundError(
|
|
f"__path__ attribute not found on {parent_name!r} "
|
|
f"while trying to find {fullname!r}", name=fullname) from e
|
|
else:
|
|
parent_path = None
|
|
return _find_spec(fullname, parent_path)
|
|
else:
|
|
module = sys.modules[fullname]
|
|
if module is None:
|
|
return None
|
|
try:
|
|
spec = module.__spec__
|
|
except AttributeError:
|
|
raise ValueError('{}.__spec__ is not set'.format(name)) from None
|
|
else:
|
|
if spec is None:
|
|
raise ValueError('{}.__spec__ is None'.format(name))
|
|
return spec
|
|
|