* [contexts](https://github.com/benjamin-hodgson/Contexts) - A BDD framework for Python 3.3+. Inspired by C#'s `Machine.Specifications`.

* [hypothesis](https://github.com/DRMacIver/hypothesis) - Hypothesis is an advanced Quickcheck style property based testing library.

* [mamba](http://nestorsalceda.github.io/mamba/) - The definitive testing tool for Python. Born under the banner of BDD.

* [pyshould](https://github.com/drslump/pyshould) - Should style asserts based on [PyHamcrest](https://github.com/hamcrest/PyHamcrest).

* [pytest](http://pytest.org/latest/) - A mature full-featured Python testing tool.

* [green](https://github.com/CleanCut/green) - A clean, colorful test runner.

* [pyvows](http://heynemann.github.io/pyvows/) - BDD style testing for Python. Inspired by [Vows.js](https://github.com/vowsjs/vows).

* [Robot Framework](https://github.com/robotframework/robotframework) - A generic test automation framework.

* [tox](https://tox.readthedocs.org/en/latest/) - Auto builds and tests [distributions](#distribution) in multiple Python versions using isolated and configurable virtualenvs.

* [Selenium](https://pypi.python.org/pypi/selenium) - Python bindings for [Selenium](http://www.seleniumhq.org/) WebDriver.

* [locust](https://github.com/locustio/locust) - Scalable user load testing tool written in Python.

* [sixpack](https://github.com/seatgeek/sixpack) - A language-agnostic A/B Testing framework.

* [splinter](https://splinter.readthedocs.org/en/latest/) - Open source tool for testing web applications.

* Mock

* [mock](https://docs.python.org/3/library/unittest.mock.html) - (Python standard library) A mocking and patching library.

* [doublex](https://pypi.python.org/pypi/doublex) - Powerful test doubles framework for Python.