Build lists in one line.
✍️ 3 exercises + code challenge in this lessonA list comprehension creates a new list from an existing iterable in a single, readable line:
new_list = [expression for item in iterable if condition]
[x * 2 for x in nums]: transform every item.[x for x in nums if x > 0]: keep only some items.[x if x > 0 else 0 for x in nums]: choose a value per item.The same syntax works for sets {...} and dictionaries {k: v ...}.
Mastering Python List Comprehension helps you write clean and reliable Python code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.
nums = [3, -1, 8, 0, -5, 12]
doubled = [n * 2 for n in nums]
positives = [n for n in nums if n > 0]
clamped = [n if n > 0 else 0 for n in nums]
squares = {n: n ** 2 for n in range(1, 6)}
print(doubled)
print(positives)
print(clamped)
print(squares)Check what you learned in “Python List Comprehension”.
Create a list of squares.
squares = [x * x x in range(5)]
What does [n for n in nums if n > 0] produce?
Use a list comprehension to print the even numbers from 1 to 10.
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