I get an error like this: ModuleNotFoundError: No module named 'mymodule' What do I need to do to make this module import work?

Question

I have my own python module in a custom location here:

/mydata/python/mylibrary/mymodule.py for linux, or for Windows: C:\mydata\python\mylibrary\mymodule.py

There are no other files or folders in the directory “mylibrary”.

When I try and import this module into a python program with the statement:

import mymodule

I get an error like this:

ModuleNotFoundError: No module named 'mymodule'

What do I need to do to make this module import work?

need help, tried everything