List Comprehensions

List comprehensions offer a concise and elegant way to create lists based on existing sequences or iterables. They are significantly faster and more readable than standard for loops for list creation.

Standard for Loop vs. Comprehension

Goal: Create a list of squares for numbers 0 through 4.

Using a Standard Loop

python squares = [] for i in range(5): squares.append(i ** 2) print(squares) # [0, 1, 4, 9, 16]

Using a List Comprehension (Recommended)

Syntax: [expression for item in iterable]

python squares_comp = [i ** 2 for i in range(5)] print(squares_comp) # [0, 1, 4, 9, 16]

Example: String Transformations

python names = ['alice', 'bob', 'charlie']

Capitalize all names

capitalized = [name.capitalize() for name in names] print(capitalized) # ['Alice', 'Bob', 'Charlie']