diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst index df184b33d0e..9fab0779aa7 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 00000000000..35d7f56f732 --- /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.