[Python-checkins] bpo-37521: No longer treat insertion into sys.modules as optional in importlib examples (GH-14723)
Miss Islington (bot)
webhook-mailer at python.org
Fri Jul 12 18:35:43 EDT 2019
https://github.com/python/cpython/commit/0827064c955f88df8ba5621d8e3d81be3cfc26a9
commit: 0827064c955f88df8ba5621d8e3d81be3cfc26a9
branch: master
author: Brett Cannon <54418+brettcannon at users.noreply.github.com>
committer: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
date: 2019-07-12T15:35:34-07:00
summary:
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
files:
A Misc/NEWS.d/next/Documentation/2019-07-12-15-09-56.bpo-37521.7tiFR-.rst
M Doc/library/importlib.rst
diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
index df184b33d0e7..9fab0779aa74 100644
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -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
diff --git a/Misc/NEWS.d/next/Documentation/2019-07-12-15-09-56.bpo-37521.7tiFR-.rst b/Misc/NEWS.d/next/Documentation/2019-07-12-15-09-56.bpo-37521.7tiFR-.rst
new file mode 100644
index 000000000000..35d7f56f732f
--- /dev/null
+++ b/Misc/NEWS.d/next/Documentation/2019-07-12-15-09-56.bpo-37521.7tiFR-.rst
@@ -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.
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