yield

In Python, the yield keyword turns a function into a generator function, returning an iterator that generates values on demand rather than generating them all at once. Using yield enables the function to maintain its state between calls, allowing you to iterate over data efficiently without the overhead of creating and storing the entire dataset in memory.

Python yield Keyword Examples

Here’s an example of how to use the yield keyword in a generator function:

Python 
>>> def count_up_to(max):
...     count = 1
...     while count <= max:
...         yield count
...         count += 1
...

>>> for count in count_up_to(3):
...     print(count)
...
1
2
3

In this example, count_up_to() is a generator function that returns an iterator. This iterator yields numbers from 1 up to a given maximum. You can use this iterator in a for loop.

How to Use Generators and Yield in Python

Tutorial

How to Use Generators and yield in Python

Build generator functions and generator expressions with the Python yield statement, and learn when lazy evaluation pays off.

intermediate python

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By Leodanis Pozo Ramos • Updated July 8, 2026 • Reviewed by Dan Bader
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