In this chapter, we've looked at a number of functions in the itertools module. This library module provides a number of functions that help us to work with iterators in sophisticated ways.
We've looked at the infinite iterators; these repeat without terminating. These include the count(), cycle(), and repeat() functions. Since they don't terminate, the consuming function must determine when to stop accepting values.
We've also looked at a number of finite iterators. Some of these are built-in, and some of these are a part of the itertools module. These work with a source iterable, so they terminate when that iterable is exhausted. These functions include enumerate(), accumulate() , chain() , groupby() , zip_longest(), zip(), compress() ...
