bpo-37521: No longer treat insertion into sys.modules as optional in importlib examples (GH-14723)

Fix importlib examples to insert any newly created modules via importlib.util.module_from_spec() immediately into sys.modules instead of after calling loader.exec_module().

Thanks to Benjamin Mintz for finding the bug.


https://bugs.python.org/issue37521
This commit is contained in:
Brett Cannon 2019-07-12 15:35:34 -07:00 committed by Miss Islington (bot)
parent a65c977552
commit 0827064c95
2 changed files with 14 additions and 9 deletions

View File

@ -1638,15 +1638,16 @@ import, then you should use :func:`importlib.util.find_spec`.
# For illustrative purposes.
name = 'itertools'
spec = importlib.util.find_spec(name)
if spec is None:
print("can't find the itertools module")
if name in sys.modules:
print(f"{name!r} already in sys.modules")
elif (spec := importlib.util.find_spec(name)) is None:
print(f"can't find the {name!r} module")
else:
# If you chose to perform the actual import ...
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
# Adding the module to sys.modules is optional.
sys.modules[name] = module
spec.loader.exec_module(module)
print(f"{name!r} has been imported")
Importing a source file directly
@ -1665,10 +1666,9 @@ To import a Python source file directly, use the following recipe
spec = importlib.util.spec_from_file_location(module_name, file_path)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
# Optional; only necessary if you want to be able to import the module
# by name later.
sys.modules[module_name] = module
spec.loader.exec_module(module)
Setting up an importer
@ -1740,8 +1740,8 @@ Python 3.6 and newer for other parts of the code).
msg = f'No module named {absolute_name!r}'
raise ModuleNotFoundError(msg, name=absolute_name)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
sys.modules[absolute_name] = module
spec.loader.exec_module(module)
if path is not None:
setattr(parent_module, child_name, module)
return module

View File

@ -0,0 +1,5 @@
Fix `importlib` examples to insert any newly created modules via
importlib.util.module_from_spec() immediately into sys.modules instead of
after calling loader.exec_module().
Thanks to Benjamin Mintz for finding the bug.