diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst index 04ff8a61da3..b446ddb3598 100644 --- a/Doc/library/unittest.mock.rst +++ b/Doc/library/unittest.mock.rst @@ -1572,15 +1572,36 @@ patch.dict :func:`patch.dict` can also be called with arbitrary keyword arguments to set values in the dictionary. - :func:`patch.dict` can be used as a context manager, decorator or class - decorator. When used as a class decorator :func:`patch.dict` honours - ``patch.TEST_PREFIX`` for choosing which methods to wrap. - .. versionchanged:: 3.8 :func:`patch.dict` now returns the patched dictionary when used as a context manager. +:func:`patch.dict` can be used as a context manager, decorator or class +decorator: + + >>> foo = {} + >>> @patch.dict(foo, {'newkey': 'newvalue'}) + ... def test(): + ... assert foo == {'newkey': 'newvalue'} + >>> test() + >>> assert foo == {} + +When used as a class decorator :func:`patch.dict` honours +``patch.TEST_PREFIX`` (default to ``'test'``) for choosing which methods to wrap: + + >>> import os + >>> import unittest + >>> from unittest.mock import patch + >>> @patch.dict('os.environ', {'newkey': 'newvalue'}) + ... class TestSample(unittest.TestCase): + ... def test_sample(self): + ... self.assertEqual(os.environ['newkey'], 'newvalue') + +If you want to use a different prefix for your test, you can inform the +patchers of the different prefix by setting ``patch.TEST_PREFIX``. For +more details about how to change the value of see :ref:`test-prefix`. + :func:`patch.dict` can be used to add members to a dictionary, or simply let a test change a dictionary, and ensure the dictionary is restored when the test ends. @@ -1793,6 +1814,8 @@ builtin :func:`ord`:: 101 +.. _test-prefix: + TEST_PREFIX ~~~~~~~~~~~