chore(tags): limit dir / tab-completion in REPL

[henryiii]

This adds __all__ and __dir__ to the tags module. This exports just the public names; type checkers respect __all__, REPL tab completion respects __dir__. It does not stop someone from using an unexported name at runtime. This is much better than trying to use underscores on things like standard imports or deleting things, and it also works for re-exporting. See https://learn.scientific-python.org/development/patterns/exports for details.

Before:

>>> import packaging.tags
>>> dir(packaging.tags)
['Any', 'AppleVersion', 'EXTENSION_SUFFIXES', 'INTERPRETER_SHORT_NAMES', 'Iterable',
 'Iterator', 'PythonVersion', 'Sequence', 'Tag', 'Tuple', '_32_BIT_INTERPRETER',
 '__all__', '__annotations__', '__builtins__', '__cached__', '__conditional_annotations__',
 '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__',
 '_abi3_applies', '_cpython_abis', '_generic_abi', '_generic_platforms',
 '_get_config_var', '_is_threaded_cpython', '_linux_platforms', '_mac_arch',
 '_mac_binary_formats', '_manylinux', '_musllinux', '_normalize_string',
 '_py_interpreter_range', '_version_nodot', 'android_platforms', 'annotations',
 'cast', 'compatible_tags', 'cpython_tags', 'generic_tags', 'interpreter_name',
 'interpreter_version', 'ios_platforms', 'logger', 'logging', 'mac_platforms',
 'parse_tag', 'platform', 'platform_tags', 're', 'struct', 'subprocess', 'sys',
 'sys_tags', 'sysconfig']

After:

>>> import packaging.tags
>>> dir(packaging.tags)
['AppleVersion', 'INTERPRETER_SHORT_NAMES', 'PythonVersion', 'Tag', 'compatible_tags',
 'cpython_tags', 'generic_tags', 'interpreter_name', 'interpreter_version', 'parse_tag',
 'platform_tags', 'sys_tags']

I've skipped exporting mac_platforms, ios_platform, and android_platforms, because _linux_platforms is hidden, but maybe those are public? Ah, nevermind, I do see them in the documentation. Interesting, I'll add them. I could list _linux_platforms here too if we want to, but it's not documented.

If this looks good, I'll work on the other modules.

[brettcannon]

tab completion respects __dir__.

Tab completion by whom?

[henryiii]

Python's old and new REPL and IPython's REPL (at least), are based on dir(item). I think static tab completion, like in VSCode, respects __all__. Edit: no, it doesn't seem to.

[henryiii]

New REPL:

(Looks like I forgot to update Python to 3.14.2, embarrassing!)

Old REPL:

(No color now looks so sad)

IPython:

Looks like vscode does not respect __all__, it's still showing me other stuff like Any. But it's not worse, at least. :) And mypy does respect __all__.