In this episode, we explore the popular pytest python testing tool with author Brian Okken, author of Python Testing with pytest. We start by discussing why pytest is so popular in the Python community: its focus on simplicity, readability, and developer ease-of-use; what makes pytest unique; the setup and teardown of tests using fixtures, parameterization, and the plugin ecosystem; mocking; why we should design for testing, and how to reduce the need for mocking; how to set up a project for testability; test-driven development, and designing your tests so that they support refactoring. Finally, we consider some complementary tools that can improve the python testing experience.