Mastering Python Design Patterns - Second Edition

Iterator pattern

In programming, we use sequences or collections of objects a lot, particularly in algorithms and when writing programs that manipulate data. One can think of automation scripts, APIs, data-driven apps, and other domains. In this chapter, we are going to see a pattern that is really useful whenever we have to handle collections of objects: the Iterator pattern.

Note the following, according to the definition given by Wikipedia:

Iterator is a design pattern in which an iterator is used to traverse a container and access the container's elements. The iterator pattern decouples algorithms from containers; in some cases, algorithms are necessarily container-specific and thus cannot be decoupled.

The iterator pattern is extensively ...