# Bonus Material {.unnumbered}

These optional chapters support the project work with everyday development habits: writing tests for small Python functions and documenting code so future you can understand the shape of the tool. They are optional in the same way snacks are optional on a long walk: technically true, but very useful.

- [Writing Tests in Python](writing-tests-in-python.ipynb)
- [Documenting Your Code](documenting-your-code.ipynb)