[3.6] bpo-27505: Retrofit module __class__ documentation from 3.7 by csabella · Pull Request #5321 · python/cpython

Expand Up @@ -1500,6 +1500,39 @@ access (use of, assignment to, or deletion of ``x.name``) for class instances. returned. :func:`dir` converts the returned sequence to a list and sorts it.

Customizing module attribute access ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. index:: single: __class__ (module attribute)
For a more fine grained customization of the module behavior (setting attributes, properties, etc.), one can set the ``__class__`` attribute of a module object to a subclass of :class:`types.ModuleType`. For example::
import sys from types import ModuleType
class VerboseModule(ModuleType): def __repr__(self): return f'Verbose {self.__name__}'
def __setattr__(self, attr, value): print(f'Setting {attr}...') setattr(self, attr, value)
sys.modules[__name__].__class__ = VerboseModule
.. note:: Setting module ``__class__`` only affects lookups made using the attribute access syntax -- directly accessing the module globals (whether by code within the module, or via a reference to the module's globals dictionary) is unaffected.
.. versionchanged:: 3.5 ``__class__`` module attribute is now writable.

.. _descriptors:
Implementing Descriptors Expand Down