map()

The map() function in Python is a built-in function that takes a function and an iterable (like a list) as arguments. It applies the function to each element of the iterable, returning a new iterable with the results. It is commonly used to efficiently perform operations on all elements of a list without using a loop.

Parameter Values

Parameter Description
function

A function to which map passes each element of given iterable.
iterables

One or more iterables (sequences like lists, tuples, etc.) whose elements are passed to the function.

Return Values

The map() function in Python returns an iterator that applies a function to every item.

How to Use map() in Python

Example 1:

The map() function in Python applies a specific function to all items in an iterable and returns a new iterable with the results.

numbers = [1, 2, 3, 4]
doubled = list(map(lambda x: x*2, numbers))
# Output: [2, 4, 6, 8]
Example 2:

You can also use map() with multiple iterables. The function will be applied to items from all iterables in parallel.

names = ['Alice', 'Bob', 'Charlie']
ages = [25, 30, 35]
description = list(map(lambda x, y: f'{x} is {y} years old', names, ages)
# Output: ['Alice is 25 years old', 'Bob is 30 years old', 'Charlie is 35 years old']
Example 3:

If you have more than one iterable, but the function takes a single argument, you can unpack the iterables using the * operator.

names = ['Alice', 'Bob', 'Charlie']
uppercase_names = list(map(lambda x: x.upper(), *names))
# Output: ['A', 'B', 'C']

Built-In Functions