Python's __init__ file makes sense

Suppose we have the following directory structure

foo/
	__init__.py
	bar.py

import foo runs foo/__init__.py (see Regular Package). import foo.bar imports the file bar.py as a module bar

Question

Why do we have a foo module which is a folder and a bar module which is a file?

Well actually, foo is a package and bar is a module in it. It starts to make sense if you consider that the file bar.py is growing and we want to split it into multiple files. Then, we can make it into a package! The directory structure will then look like:

foo/
	__init__.py
	bar/
		__init__.py
		baz1.py
		baz2.py

All the things that bar.py exposed earlier can now be kept inside bar/__init__.py. This makes the change transparent to all users who import bar.