*The single line of Python code is more powerful than you may expect. In fact, you can compress whole algorithms in a single line of Python code. In this tutorial, you’ll learn how to use the built-in map() function in Python to one-linerize a critical step that would otherwise take multiple lines of Python code: to modify each element in a given iterable. *

Python’s `map()`

function applies a specific function to each element in a given iterable. It takes two arguments:

**Function**: The function to apply on each element of an iterable. In most cases, it’s a lambda function to defined once and on the fly.**Iterable**: Each iterable element is modified according to the function defined in the first argument.

The result is a `map()`

object, an iterator that saves all mapped elements so that you can iterate over them.

Consider the following `map()`

one-liner that changes each element `x`

of a list to the value of `x+1`

:

print(list(map(lambda x: x + 1, [1, 2, 3]))) # [2, 3, 4]

You create a `map`

function applies the function to each element in the list and returns a new map object. This is converted back to a list using the `list(...)`

function.

Try it yourself in our interactive code shell:

**Exercise**: Change the one-liner to calculate the square number of each list element.

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