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 func(x):
    return x + 1

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

To execute it:

$ py.test
======= test session starts ========
platform linux -- Python 3.4.3, pytest-2.8.5, py-1.4.31, pluggy-0.3.1
collected 1 items

test_sample.py F

======= FAILURES ========
_______ test_answer ________

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

test_sample.py:5: AssertionError
======= 1 failed in 0.12 seconds ========

Due to py.test'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 (or trial), nose test suites out of the box;
• Python2.6+, Python3.2+, PyPy-2.3, Jython-2.5 (untested);
• Rich plugin architecture, with over 150+ external plugins and thriving community;

Documentation

For full documentation, including installation, tutorials and PDF documents, please see http://pytest.org.

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.

License

Copyright Holger Krekel and others, 2004-2016.

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