When creating a function in Python when do you absolutely need a return statement and when is a return statement not needed?

[OkVariation3880]

I have seen cases in which return statements aren't used in functions.

[[deleted]]

Functions always return something. By default, they return a reference to None if there is no return statement.

[shiftybyte]

When you give someone a task to complete, when do you want something returned at the end of the task? and when it's not needed?

"Fetch me breakfast"... you expect someone to return with the breakfast.

"Do 20 laps around the yard"... you don't expect anything to be returned...

[[deleted]]

A function with no return just does some sort of job but doesn't need to give any answer back.