pkg_resources is deprecated, soon to be removed

[DArtagan]

While launching our application, we've begun to see the following message in the terminal at start-up:

venv/lib/python3.13/site-packages/sassutils/wsgi.py:9: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
  from pkg_resources import resource_filename

For context, the lines 107-111 from libsass-python/sassutils/wsgi.py look like:

        for package_name in self.manifests:
            if package_name in self.package_dir:
                continue
            path = resource_filename(package_name, '')
            self.package_dir[package_name] = path

An approach

The recommended migration path is to move from pkg_resources to importlib.resources: https://importlib-resources.readthedocs.io/en/latest/migration.html#pkg-resources-resource-filename

Referring to the compatibility chart on https://pypi.org/project/importlib-resources/ for a sense of whether use of the backports library is necessary.

[PetitPotiron]

I also face this issue, but I think it's easy to migrate.

[PetitPotiron]

One should change the imports of pkg_resources to

# For getting resources filenames, we now use importlib.resources
from contextlib import ExitStack
from sys import version_info

# However, we check the Python version in order to still support older
# versions which don't support importlib.resources (backwards compatibility)
if version_info >= (3, 7):
    # Use importlib.resources for Python 3.7 and later
    from importlib import resources
else:
    # Use importlib_resources for Python 3.6 and earlier
    import importlib_resources as resources

And then change the 107-111 lines you are talking about with

        for package_name in self.manifests:
            if package_name in self.package_dir:
                continue
            ref = resources.files(package_name) / 'resource.dat'
            with resources.as_file(ref) as res_path:
                path = res_path
            self.package_dir[package_name] = path

However, I don't understand this package enough to do a PR, so someone do it instead please. I don't understand how we should update the tests, or the setup.py files, and I feel like someone used to this project should do this.

[asottile]

I think it's probably fine to drop whatever python versions are necessary in order to simplify those conditionals. should be mostly drop-in at that point then