Python Basics · Data Structures · Lesson 19 of 36
List Comprehensions
Concept
List Comprehensions
A list comprehension builds a new list in one concise line, combining a loop and a condition.
Under the hood it's equivalent to a for loop that appends to a new list, just written more compactly and often considered more "Pythonic."
- Explain the core idea behind List Comprehensions.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
Self-check before continuing
Without looking at the example, describe what changes when you modify one input in List Comprehensions. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Write a list comprehension that returns only the even numbers from a list.
Ask about this lesson or your next move. The guide explains the path without taking the work away from you.
Ready for the next lesson?
Mark this lesson complete when you have finished the exercise.
Console