The main two reasons that I can think of to include this even when you have no intention of importing this as a library are:
For unit testing you will need to import as a module.
Sometimes I will run a python interactive interpreter and then import my script so that I can do some manual testing without needing to change my main function or if stmt.
The main two reasons that I can think of to include this even when you have no intention of importing this as a library are: