Most robust way to determine package version

[fkiraly]

I've tried to investigate how to determine robustly the version of a package in the python environment.
Currently I know of no robust way that would be useable in local development.

module.__version__ does not always work and needs to be manually populated by the package owner - it is well possible to release a package without the __version__ attribute.

I also found a way using importlib:

import importlib

version = importlib.metadata.version("pkg-name")

But this seems to retrieve the version from when the package was installed in the environment, irrespective of any updates made to the package later that may have changed __version__ or pyproject.toml. This makes it dodgy for local development.

Does anyone know a way that works under both conditions? That is: (a) for any python package released on pypi, even if the maintainer forgets to populate common attrbiutes; (b) for local development with an editable environment, robust to versio changes in the editable environment.