Iterators & Generators

11. Iterators & Generators#

Iterators and generators are the backbone of Python’s memory-efficient data processing.

  • The iterator protocol: __iter__ and __next__

  • Built-in lazy iterators

  • Custom iterator classes

  • Generator functions and generator expressions

  • Lazy pipelines for streaming data

Video

This overview introduces generator functions and lazy value production with yield.

Learning Goals

By the end of this chapter, you will be able to:

  1. Explain Python’s iterator protocol and use iter() and next() manually

  2. Use built-in lazy iterators such as enumerate(), zip(), map(), filter(), and reversed()

  3. Build custom iterator classes that implement the iterator protocol

  4. Write generator functions with yield

  5. Design multi-step data pipelines using chained generators

Chapter Flow

Chapter Overview Slides