Python, for all its power and popularity, has long lacked a form of flow control found in other languages—a way to take a value and match it elegantly against one of a number of possible conditions.

Take dynamic typing as an example. It seems amazing at first: Python literally figures out by itself what sort of value a variable might take, and you don’t need to waste another line of code by ...

Part of the power of a computing environment lies in the ability to store, manipulate, and recall information. This is done using variables and statements. Here we create a variable a, and assign to ...