pytest: helps you write better programs

The pytest framework makes it easy to write small tests, yet scales to support complex functional testing for applications and libraries.

An example of a simple test:

# content of test_sample.py
def inc(x):
    return x + 1


def test_answer():
    assert inc(3) == 5

To execute it:

$ pytest
=========================== test session starts ============================
platform linux -- Python 3.x.y, pytest-5.x.y, py-1.x.y, pluggy-0.x.y
cachedir: $PYTHON_PREFIX/.pytest_cache
rootdir: $REGENDOC_TMPDIR
collected 1 item

test_sample.py F                                                     [100%]

================================= FAILURES =================================
_______________________________ test_answer ________________________________

    def test_answer():
>       assert inc(3) == 5
E       assert 4 == 5
E        +  where 4 = inc(3)

test_sample.py:6: AssertionError
============================ 1 failed in 0.12s =============================

Due to pytest’s detailed assertion introspection, only plain assert statements are used. See Getting Started for more examples.

Features

  • Detailed info on failing assert statements (no need to remember self.assert* names);
  • Auto-discovery of test modules and functions;
  • Modular fixtures for managing small or parametrized long-lived test resources;
  • Can run unittest (including trial) and nose test suites out of the box;
  • Python 3.5+ and PyPy 3;
  • Rich plugin architecture, with over 315+ external plugins and thriving community;

Documentation

Please see Contents for full documentation, including installation, tutorials and PDF documents.

Bugs/Requests

Please use the GitHub issue tracker to submit bugs or request features.

Changelog

Consult the Changelog page for fixes and enhancements of each version.

Support pytest

Open Collective is an online funding platform for open and transparent communities. It provide tools to raise money and share your finances in full transparency.

It is the platform of choice for individuals and companies that want to make one-time or monthly donations directly to the project.

See more datails in the pytest collective.

pytest for enterprise

Available as part of the Tidelift Subscription.

The maintainers of pytest and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use.

Learn more.

Security

pytest has never been associated with a security vunerability, but in any case, to report a security vulnerability please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.

License

Copyright Holger Krekel and others, 2004-2017.

Distributed under the terms of the MIT license, pytest is free and open source software.