Skip to content


Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time

This is a pytest plug-in which automatically selects and re-executes only tests affected by recent changes. How is this possible in dynamic language like Python and how reliable is it? Read here: Determining affected tests


pip install pytest-testmon

# build the dependency database and save it to .testmondata
pytest --testmon

# change some of your code (with test coverage)

# only run tests affected by recent changes
pytest --testmon

To learn more about different options you can use with testmon, please head to

Call for opensource projects: try testmon in CI with no effort or risk.

We would like to run testmon within your project, collect data and improve! We'll prepare the PR for you and set everything up so that no tests are deselected initially. You can start using the full functionality whenever the reliability and time savings seem right! Please get in touch and we'll contact you shortly.