A Python module extends the Python execution environment by adding new classes, functions and helpful constants. We tell the Python interpreter to fetch a module with a variation on the import statement. There are several variations on import , which we'll cover in depth in Part IV, “Components, Modules and Packages”.

For now, we'll use the simple import :

import m

This will import module m. Only the module's name, m is made available. Every name inside the module m must be qualified by prepending the module name and a .. So if module m had a function called spam, we'd refer to it as m.spam.

There are dozens of standard Python modules. We'll get to the most important ones in Part IV, “Components, Modules and Packages”. For now, we'll focus on extending the math capabilities of the basic expressions we've looked so far.