Python TutorialLesson 25Free preview

Python Iterators

This lesson is part of Python · All levels

Summary

An iterator is an object that returns elements one by one, so that large data does not need to be loaded into memory at once. We get the iterator by calling iter() and then taking each value using next() until we stop with the exception of StopIteration. In Python, almost all collections and even output generators are iterable that can be run in a for loop.

Key points

The iterable is the repeatable object, whereas the iterator provides the element.
Iter() makes the iterator and next() takes one element next.
The iterator stops by triggering the StopIteration when the element runs out.
The Iterator saves memory by processing data one by one.

Full lesson

Code examples and quizzes

Full lessons, code examples, and quizzes are available to subscribers. 5 questions.