Welcome to the tox automation project

vision: standardize testing in Python

tox aims to automate and standardize testing in Python. It is part of a larger vision of easing the packaging, testing and release process of Python software.

What is tox?

tox is a generic virtualenv management and test command line tool you can use for:

  • checking your package installs correctly with different Python versions and interpreters
  • running your tests in each of the environments, configuring your test tool of choice
  • acting as a frontend to Continuous Integration servers, greatly reducing boilerplate and merging CI and shell-based testing.

Basic example

First, install tox with pip install tox. Then put basic information about your project and the test environments you want your project to run in into a tox.ini file residing right next to your setup.py file:

# content of: tox.ini , put in same dir as setup.py
envlist = py26,py27
deps=pytest       # install pytest in the venvs
commands=pytest  # or 'nosetests' or ...

You can also try generating a tox.ini file automatically, by running tox-quickstart and then answering a few simple questions.

To sdist-package, install and test your project against Python2.6 and Python2.7, just type:


and watch things happening (you must have python2.6 and python2.7 installed in your environment otherwise you will see errors). When you run tox a second time you’ll note that it runs much faster because it keeps track of virtualenv details and will not recreate or re-install dependencies. You also might want to checkout tox configuration and usage examples to get some more ideas.

Current features

  • automation of tedious Python related test activities

  • test your Python package against many interpreter and dependency configs

    • automatic customizable (re)creation of virtualenv test environments
    • installs your setup.py based project into each virtual environment
    • test-tool agnostic: runs pytest, nose or unittests in a uniform manner
  • (new in 2.0) plugin system to modify tox execution with simple hooks.

  • uses pip and setuptools by default. Support for configuring the installer command through install_command=ARGV.

  • cross-Python compatible: CPython-2.6, 2.7, 3.2 and higher, Jython and pypy.

  • cross-platform: Windows and Unix style environments

  • integrates with continuous integration servers like Jenkins (formerly known as Hudson) and helps you to avoid boilerplatish and platform-specific build-step hacks.

  • full interoperability with devpi: is integrated with and is used for testing in the devpi system, a versatile pypi index server and release managing tool.

  • driven by a simple ini-style config file

  • documented examples and configuration

  • concise reporting about tool invocations and configuration errors

  • professionally supported

  • supports using different / multiple PyPI index servers