This plugin provides a clean minimal set of command line options that are added to pytest. For further control of coverage use a coverage config file.

For example if tests are contained within the directory tree being measured the tests may be excluded if desired by using a .coveragerc file with the omit option set:

py.test --cov-config .coveragerc

Where the .coveragerc file contains file globs:

omit = tests/*

For full details refer to the coverage config file documentation.

Note that this plugin controls some options and setting the option in the config file will have no effect. These include specifying source to be measured (source option) and all data file handling (data_file and parallel options).

If you wish to always add pytest-cov with pytest, you can use addopts under pytest or tool:pytest section. For example:

addopts = --cov=<project-name> --cov-report html


A unfortunate consequence of’s history is that .coveragerc is a magic name: it’s the default file but it also means “try to also lookup coverage configuration in tox.ini or setup.cfg”.

In practical terms this means that if you have your coverage configuration in tox.ini or setup.cfg it is paramount that you also use --cov-config=tox.ini or --cov-config=setup.cfg.

You might not be affected but it’s unlikely that you won’t ever use chdir in a test.