In this chapter, we covered why writing tests is important in order to produce high-quality software and to give you the confidence to introduce changes without fear. After that, we took a look at the built-in unittest module and how it can be used to write tests. Finally, we had a quick introduction to pytest, discovered how simple it is to write tests with it, looked at its key features, and also looked at the vast quantity of third-party plugins that cover a wide range of use cases and frameworks.
In the next chapter, we will learn how to install pytest, how to write simple tests, how to better organize them into files and directories within your project, and how to use the command line effectively.
