You want to contribute? That's great! Welcome aboard. First of all see these links for general guidelines for contributing to open source.
- The Travis-CI build and AppVeyor build (which also run the test suite) should pass on each commit.
- Your contributions should be under GPLv3+ or a compatible free software licence, but please don't put them under the AGPL, which adds additional restrictions.
- The code should be compatible with both Python 2.7.x and Python 3.4.x-and-above.
- Translate PySol to a human language you know.
- Try to reproduce open issues
- Try to fix bugs.
- Add new games.
- Improve the documentation / online help
- Refactor the code.
- Add new features.
- Contribute graphics
- Improve the site
- Make a monetary donation.
- Star or Watch the repository on GitHub
First of all there is the "Solitaire Wizard" which may be used to generate many custom variants. It lives in the Edit menu.
Otherwise, the games' sources live under the pysollib/games/ directory in the repository, and are written in Python 2.7/3.x and you can try inheriting from an existing variant class.