pytest-mock

Thin-wrapper around the mock package for easier use with pytest

pytest-mock Permissive license MIT Active ★ 2,037 v3.15.1 released 2025-09-16

Install

pytest-mock on PyPI

pip

pip install pytest-mock

uv

uv add pytest-mock

poetry

poetry add pytest-mock

Package facts

License	MIT (permissive)
Python support	supports the current Python release (>=3.9)
Install friction	low — pure-Python wheel
Runtime dependencies	1 — pytest
Maintenance	actively maintained — 331 days since the last release
Last repo commit	2026-08-13
First released	2014-07-17
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: pytest_mock-3.15.1-py3-none-any.whl

Keywords: pytest, mock

Development Status :: 5 - Production/StableFramework :: PytestIntended Audience :: DevelopersLicense :: OSI Approved :: MIT LicenseOperating System :: OS IndependentProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.9Topic :: Software Development :: Testing

About pytest-mock

from the package's own PyPI description — quoted content, verbatim

=========== pytest-mock ===========

This plugin provides a mocker fixture which is a thin-wrapper around the patching API provided by the mock package <http://pypi.python.org/pypi/mock>_:

.. code-block:: python

import os

class UnixFS:

    @staticmethod
    def rm(filename):
        os.remove(filename)

def test_unix_fs(mocker):
    mocker.patch('os.remove')
    UnixFS.rm('file')
    os.remove.assert_called_once_with('file')

Besides undoing the mocking automatically after the end of the test, it also provides other nice utilities such as spy and stub, and uses pytest introspection when comparing calls.

.. |version| image:: http://img.shields.io/pypi/v/pytest-mock.svg :target: https://pypi.python.org/pypi/pytest-mock

.. |anaconda| image:: https://img.shields.io/conda/vn/conda-forge/pytest-mock.svg :target: https://anaconda.org/conda-forge/pytest-mock

.. |ci| image:: https://github.com/pytest-dev/pytest-mock/workflows/test/badge.svg :target: https://github.com/pytest-dev/pytest-mock/actions

.. |coverage| image::...

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AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

pytest-mock provides a `mocker` fixture that wraps the mock package's patching API for pytest, automatically cleaning up patches after each test and offering utilities like spy and stub.

Low friction: pure Python wheel with only pytest as a runtime dependency. Actively maintained with recent releases and 2037 GitHub stars; last commit 2026-08-13.

MIT license (permissive) imposes no significant restrictions; you may use, modify, and distribute freely with minimal attribution requirements.

Usage

pip install pytest-mock

import os
from unittest.mock import call

def test_example(mocker):
    mocker.patch('os.remove')
    os.remove('file')
    os.remove.assert_called_once_with('file')

Requires Python >=3.9 and pytest to be installed.

Verdict: pytest-mock is a stable, widely-used testing utility (top 1000 PyPI, 2037 stars, active maintenance) with no known vulnerabilities, low install friction, and permissive licensing. It is a safe, standard choice for mock-based testing in pytest projects.

Needs verification

Whether the mocker fixture's automatic cleanup behavior has any edge cases or performance implications for large test suites.
How the spy and stub utilities compare in capability or performance to direct mock.patch usage.

pytest mock fixturemocking in pytestpatch objects in testspytest spy stubmock patching pytest plugintest mocking utilitiespytest mock wrapper