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contextlib2 is a backport of the standard library's contextlib module <https://docs.python.org/3/library/contextlib.html>_ to
earlier Python versions.

It also sometimes serves as a real world proving ground for possible future
enhancements to the standard library version.

Licensing

As a backport of Python standard library software, the implementation, test
suite and other supporting files for this project are distributed under the
Python Software License used for the CPython reference implementation.

The one exception is the included type hints file, which comes from the
typeshed project, and is hence distributed under the Apache License 2.0.

Development

contextlib2 has no runtime dependencies, but requires setuptools and
wheel at build time to generate universal wheel archives.

Local testing is a matter of running::

python3 -m unittest discover -t . -s test

You can test against multiple versions of Python with
tox <https://tox.testrun.org/>_::

pip install tox
tox

Versions currently tested in both tox and GitHub Actions are:

CPython 3.6
CPython 3.7
CPython 3.8
CPython 3.9
CPython 3.10
PyPy3

Updating to a new stdlib reference version
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

As of Python 3.10, 4 files needed to be copied from the CPython reference
implementation to contextlib2:

Doc/contextlib.rst -> docs/contextlib2.rst
Lib/contextlib.py -> contextlib2/__init__.py
Lib/test/test_contextlib.py -> test/test_contextlib.py
Lib/test/test_contextlib_async.py -> test/test_contextlib_async.py

The corresponding version of contextlib2/__init__.pyi also needs to be
retrieved from the typeshed project::

wget https://raw.githubusercontent.com/python/typeshed/master/stdlib/contextlib.pyi

For the 3.10 sync, the only changes needed to the test files were to import from
contextlib2 rather than contextlib. The test directory is laid out so
that the test suite's imports from test.support work the same way they do in
the main CPython test suite.

The following patch files are saved in the dev directory:

changes made to contextlib2/__init__.py to get it to run on the older
versions (and to add back in the deprecated APIs that never graduated to
the standard library version)
changes made to contextlib2/__init__.pyi to make the Python version
guards unconditional (since the contextlib2 API is the same on all
supported versions)
changes made to docs/contextlib2.rst to use contextlib2 version
numbers in the version added/changed notes and to integrate the module
documentation with the rest of the project documentation

Package profile

contextlib2

Releases

Release table

PyPI Downloads

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Details

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Package description