python: specify packages to install for each module

[james-rms]

Changelog

• Fixed: python packages mcap, mcap-protobuf-support, mcap-ros1-support, mcap-ros2-support now only install their main packages rather than all packages including tests.
• Fixed: Add type annotations to __init__ methods with no arguments implementing this guide: https://mypy.readthedocs.io/en/stable/class_basics.html#annotating-init-methods

Docs

Description

Rely on setuptools' auto-discovery mechanism to find the python packages we're trying to expose while auto-excluding tests, which were previously being included into users' install directories.

Testing

• Inspected wheel contents using python -m zipfile --list mcap_protobuf_support-0.5.2-py3-none-any.whl to ensure that the whole library content is present and no test directories are present.

[linear]

FG-8817 Python `mcap` and `mcap-protobuf-support` create `tests/` outside of normal namespace.

[indirectlylit]

According to the docs:

Automatic discovery will only be enabled if you don’t provide any configuration for packages and py_modules. If at least one of them is explicitly set, automatic discovery will not take place.

And, during automatic discovery, tests is part of FlatLayoutPackageFinder.DEFAULT_EXCLUDE and FlatLayoutModuleFinder.DEFAULT_EXCLUDE.

So if I'm understanding all of that correctly, it might suffice to simply delete these config lines and let the flat-layout/adhoc discovery take place, and tests will be automatically excluded.

It sounds like this is a different codepath from find:, which is documented under custom discovery.

All that said, I think the change you made here is also good because being explicit is safe and straightforward.