Return Keyword in Python – A Simple Illustrated Guide

Python return keyword - visual example

Python’s return keyword commands the execution flow to exit a function immediately and return a value to the caller of the function. You can specify an optional return value—or even a return expression—after the return keyword. If you don’t provide a return value, Python will return the default value None to the caller.

Python Return Keyword Video

https://youtu.be/9nDzD6splRk

Return Keyword Followed by Return Value

Here’s an example of the return keyword in combination with a return value:

def f():
    return 4

print(f())
# OUTPUT: 4

Within function f(), Python returns the result 4 to the caller. The print() function then prints the output to the shell.

Return Keyword Followed by Return Expression

Here’s an example of the return keyword in combination with a return expression:

def f():
    return 2+2

print(f())
# OUTPUT: 4

Within function f(), Python evaluates the expression 2+2=4 and returns the result 4 to the caller. The print() function then prints the output to the shell.

Return Keyword Followed by No Value

Here’s an example of the return keyword without defining a return value:

def f():
    return

print(f())
# OUTPUT: None

Within function f(), Python returns the default value None to the caller. The print() function then prints the output to the shell.

Interactive Code Shell

Run the following code in your browser:

Exercise: Change the three return values to 42, 42, and ‘Alice’ in the interactive code shell!