That's an implementation-detail. Nothing prevents the import from diving automatically into the file. But doing so would open the door for name-shadowing, as wi

That's an implementation-detail. Nothing prevents the import from diving automatically into the file. But doing so would open the door for name-shadowing, as with a package you could have a separate mp.py for import, or a definition of mp in __init__.py. And this would be another confusion for people, and a performance-problem maybe.