= Python ContextLib =

'''`contextlib`''' is a module for working with [[Python/ContextManager|context managers]].

<<TableOfContents>>

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== Decorators ==



=== @ContextManager ===

To convert a function that yields a value into a context manager, try:

{{{
from contextlib import contextmanager

@contextmanager
def managed_resource():
    resource = acquire_resource()
    try:
        yield resource
    finally:
        release_resource(resource)

with managed_resource() as resource:
    ...
}}}

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== Abstract Base Classes ==

The module contains two abstract base classes that can be used with `isinstance` or `issubclass`, and for [[Python/TypeAnnotation|type annotations]]



=== AbstractContextManager ===

Implements a simple `__enter__()` method (which returns `self`) and an abstract `__exit__()` method (which returns `None`).



=== AbstractAsyncContextManager ===

Implements a simple `__aenter__()` method (which returns `self`) and an abstract `__aexit__()` method (which returns `None`).

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== See also ==

[[https://docs.python.org/3/library/contextlib.html|Python contextlib module documentation]]

[[https://pymotw.com/3/contextlib/|Python Module of the Day article for contextlib]]



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