====== modules ======

[[https://docs.python.org/3/reference/import.html#regular-packages|5.2.1. Regular packages]]

Python defines two types of packages, [[https://docs.python.org/3/glossary.html#term-regular-package|regular]] packages and [[https://docs.python.org/3/glossary.html#term-namespace-package|namespace]] packages. Regular packages are traditional packages as they existed in Python 3.2 and earlier. A regular package is typically implemented as a directory containing an __init__.py file. When a regular package is imported, this __init__.py file is implicitly executed, and the objects it defines are bound to names in the package’s namespace.

[[https://peps.python.org/pep-0420/|PEP 420 – Implicit Namespace Packages]]


===== __init__.py =====

It is required to make Python tread directories as packages. It can be simply empty file.
This file is always executed when any part of module is imported.

===== __main__.py =====

Most commonly, the ''__main__.py'' file is used to provide a command-line interface for a package.
''__main__.py'' will be executed when the package itself is invoked directly from the command line using the -m flag.
[[https://docs.python.org/3/library/__main__.html#main-py-in-python-packages]]