Python Anonymous/Lambda Function

Learn how to write short anonymous functions using lambda.

A lambda is a small, anonymous function with a single expression.

Syntax

lambda arguments: expression

Example

double = lambda x: x * 2
print(double(5))  # 10

This is similar to:

def double(x):
    return x * 2

Common Uses

lambda is often used with higher‑order functions like map() and filter().

nums = [1, 2, 3, 4, 5]

evens = list(filter(lambda x: x % 2 == 0, nums))
doubled = list(map(lambda x: x * 2, nums))

print(evens)    # [2, 4]
print(doubled)  # [2, 4, 6, 8, 10]

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