[spec] Clarification: Are symbols not listed in `__all__` ever considered public? about typing HOT 1 OPEN

First, the document you're citing applies to type stubs and "py.typed" libraries. It doesn't define rules for local modules or modules in libraries that are not "py.typed".

The __all__ list defines the symbols that are imported via a wildcard import. All such symbols are treated as public in a type stub or a "py.typed" module. Symbols that are not listed within __all__ are not imported via a wildcard import, and they may be considered public or private according to the other rules listed in the document.

In the example you provided, assuming that module.py is part of a "py.typed" package, T and identity would be considered public. TypeVar is private because it does not use a redundant form of import (i.e. from typing import TypeVar as TypeVar).

from typing.