We need a working Python interpreter with the pytest framework installed. Pytest can be installed with the following:
$ pip install pytest
The examples have been written on Python 3.7 and pytest 5.4.3 but should work on most modern Python versions. You can find the code files present in this chapter on GitHub at https://github.com/PacktPublishing/Crafting-Test-Driven-Software-with-Python/tree/main/Chapter05.