A pure Python implementation of the Cassowary constraint-solving algorithm. Cassowary is the algorithm that forms the core of the OS X and iOS visual layout mechanism.

Cassowary is compatible with both Python 2 or Python 3. To install Cassowary in your virtualenv, run:

$ pip install cassowary

Then, in your Python code, you can create and solve constraint systems. See the documentation for examples of what this looks like in practice.

Documentation for Cassowary can be found on Read The Docs.

Cassowary is part of the BeeWare suite. You can talk to the community through:

• @pybeeware on Twitter
• The BeeWare Users Mailing list, for questions about how to use the BeeWare suite.
• The BeeWare Developers Mailing list, for discussing the development of new features in the BeeWare suite, and ideas for new tools for the suite.

If you experience problems with Cassowary, log them on GitHub. If you want to contribute code, please fork the code and submit a pull request.