If/Else in a List Comprehension

Better Stack Team
Updated on June 19, 2024

You can use if/else statements in a list comprehension to conditionally include elements in the resulting list. The syntax for this is:

 
[expression_if_true if condition else expression_if_false for item in iterable]

Here's an example:

 
# List comprehension with if/else
numbers = [1, 2, 3, 4, 5]
new_numbers = [x if x % 2 == 0 else x * 2 for x in numbers]

print(new_numbers)  # Output: [2, 2, 6, 4, 10]

In this example, the list comprehension doubles each odd number and leaves even numbers unchanged.

You can also use nested if/else statements for more complex conditions:

 
# List comprehension with nested if/else
numbers = [1, 2, 3, 4, 5]
new_numbers = [x if x % 2 == 0 else x * 2 if x < 4 else x * 3 for x in numbers]

print(new_numbers)  # Output: [2, 2, 6, 12, 15]

In this example, if the number is less than 4, it doubles odd numbers; otherwise, it multiplies them by 3.

Got an article suggestion? Let us know
Explore more
Licensed under CC-BY-NC-SA

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Make your mark

Join the writer's program

Are you a developer and love writing and sharing your knowledge with the world? Join our guest writing program and get paid for writing amazing technical guides. We'll get them to the right readers that will appreciate them.

Write for us
Writer of the month
Marin Bezhanov
Marin is a software engineer and architect with a broad range of experience working...
Build on top of Better Stack

Write a script, app or project on top of Better Stack and share it with the world. Make a public repository and share it with us at our email.

community@betterstack.com

or submit a pull request and help us build better products for everyone.

See the full list of amazing projects on github