Organizing Our Thoughts

In this chapter, you learned the following:

• A module is a collection of functions and variables grouped together in a file. To use a module, you must first import it using import «modulename». After it has been imported, you refer to its contents using «modulename».«functionname» or «modulename».«variable».

• Variable __name__ is created by Python and can be used to specify that some code should only run when the module is run directly and not when the module is imported.

• Programs have to do more than just run to be useful; they have to run correctly. One way to ensure that they do is to test them, which you can do in Python using module doctest.