Python Data Structures and Algorithms Tutorial

List Comprehension in Python

❮ Previous Next ❯

List comprehension is a concise and powerful way to create lists in Python. It allows us to create a new list by applying an expression to each item in an existing iterable and optionally filtering the items based on a condition.

In this tutorial, we'll learn about how to use list comprehension in Python with some examples.

Basic Syntax

List comprehensions consist of the following components:

new_list = [expression for item in iterable if condition]

new_list: The resulting list.
expression: An operation to perform on each item.
item: A variable representing an item in the iterable.
iterable: The source of items (e.g., a list or range).
condition (optional): A filter to include only specific items.

Examples

Example 1: Creating a list of squares.

squares = [x**2 for x in range(1, 6)]
print(squares)

The iterable is a range from 1 to 5.
The expression is x**2, which squares each number.
There is no condition, so all items from the range are included.

Output:

[1, 4, 9, 16, 25]

Example 2: Filtering even numbers.

squares = [x**2 for x in range(1, 6)]
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
even_numbers = [x for x in numbers if x % 2 == 0]
print(even_numbers)

The iterable is a list of numbers.
The expression is x, which keeps the number as is.
The condition checks if the number is even.

Output:

[1, 4, 9, 16, 25]

❮ Previous Next ❯

Python Data Structures and Algorithms Tutorial

Python Data Structures and Algorithms Tutorial

Introduction to Data Structures and Algorithms

Python Lists

Popular LeetCode List Questions

Python Dictionaries

Popular LeetCode Dictionary Questions

Linear Data Structure

Non Linear Data Structure

List Comprehension in Python

Basic Syntax

Examples

Important Links