Document __path__

[techtonik]

This guide is a de-facto reference for all things that surrounded by double underscore, so it would be nice to see __path__ there as well.

[BobStein]

Agreed, @techtonik I'm inclined to fork and add:

• Appendix 3: Magic Attributes (e.g. __path__ __all__)
• Appendix 4: Magic File Names (e.g. __init__.py).

Thoughts?

[techtonik]

Seems fine.

[westurner]

If a package’s init.py code defines a list named __all__, it is taken to be the list of module names that should be imported when from package import * is encountered. It is up to the package author to keep this list up-to-date

https://docs.python.org/3/tutorial/modules.html#importing-from-a-package

[westurner]

If the module is a package (either regular or namespace), the module object’s __path__ attribute must be set. The value must be iterable, but may be empty if __path__ has no further significance. If __path__ is not empty, it must produce strings when iterated over. More details on the semantics of __path__ are given below.

Non-package modules should not have a path attribute.

https://docs.python.org/3/reference/import.html#path

... https://docs.python.org/3/reference/import.html#import-related-module-attributes