Skip to main content

A parallel service for tox

Project description Updates Python 3

A command line service that runs your tox tests in parallel, using threading and multicore CPUs.

See your tox environments in a dashboard and automatically watch source folders for file changes and re-run tests.

See : for an example screenshot


Linux users may need to install libncurses5-dev before using Tox. If you see an error “ImportError: No module named ‘_curses’” this is because of the Requirement.


To install, run

pip install retox

Then from any project that has a tox.ini file setup and using tox, you can simply run


This will start the service, from where you can press (b) to rebuild on demand.

Watching folders

Retox can watch one or many directories for file changes and re-run the tox environments when changes are detected

retox -w my_project_folder -w my_test_folder

Excluding paths

Retox will ignore files matching a given regex:

retox -w my_project_folder --exclude='.*\.(swp|pyc)$'

Tox support

Any tox arguments can be given to the command, and using –help to get a full list of commands. Tox arguments will be passed to all virtualenvs

retox -e py27,py36

multicore configuration

The number of concurrent processes in the threadpool can be set using the -n parameter. By default this will be equal to the number of CPU’s on the OS. If you want to expand or throttle this, use the flag to change the size of the threadpool.

retox -n 4


2 files will be created - .retox.log, which is a file for all runs of the logs for the virtual environments. This can be handy to tail to see live output .retox.json - a JSON file with the virtualenv tasks and specific command output.


This was inspired by the detox project, which was created by the tox development team. I worked and then significantly changed the way it works to support re-running environments with ease.

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

retox-1.5.0.tar.gz (525.5 kB view hashes)

Uploaded source

Built Distribution

retox-1.5.0-py3-none-any.whl (13.4 kB view hashes)

Uploaded py3

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page