Here is a list of information you can refer to:

• The unittest module of the Python standard library contains comprehensive documentation on how to start building a test suite (https://docs.python.org/3/library/unittest.html)
• Hypothesis official documentation (https://hypothesis.readthedocs.io/en/latest/)
• pytest official documentation (https://docs.pytest.org/en/latest/)
• The Cathedral and the Bazaar: Musings on Linux and Open Source by an Accidental Revolutionary (CatB), written by Eric S. Raymond (publisher O'Reilly Media, 1999)