You now know most of the basic Python language. While the core language is powerful in itself, Python gives you more tools to play with. A standard installation includes a set of modules called the standard library. You have already seen some of them (math and cmath, for example), but there are many more. This chapter shows you a bit about how modules work and how to explore them and learn what they have to offer. Then the chapter offers an overview of the standard library, focusing on a few selected useful modules.