Replace deprecated package pkg_resources

[jeffjennings]

pkg_resources is deprecated; this PR replaces its single use in the code with importlib_metadata as recommended in the first link.

Closes #37

[jeffjennings]

I need a review to merge. Please feel free to merge and delete branch once reviewed, thanks! [Never mind, auto-merge is enabled once checks pass.]

[pllim]

Is this really necessary though? Are you using setuptools_scm ?

[pllim]

from .version import version as __version__ should have been enough. You can throw in setting __version__ to empty string on ImportError if you want. But should not need special handling like this anymore.

[jeffjennings]

I see. There is no version.py file, so from .version import version as __version__ would require creating one. But for now I'm not looking to rewrite the project setup files, just trying to make minor changes such that learn-astropy workflows that depend on this package can succeed. Within that scope, I think the solution I have is ok for the moment, as it's slightly altering the previous version of the code (even if that wasn't done in the optimal way), and using a core python package to do so. An issue in this repo for updating the setup files would be useful, but right now I'd like to focus on getting the learn pipeline to work again.

[adrn]

version.py should be generated by setuptools_scm during the build process, so that file should be there by the time an import happens. But I think it's not configured correctly -- try adding:

[project]
dynamic = ["version"]

[tool.setuptools_scm]
version_file = "astropylibrarian/_version.py"

to the pyproject.toml file. Then, the code in __init__.py can be what @pllim suggested:

try:
    from ._version import version as __version__
except ImportError:
    __version__ = ""

[adrn]

Oh but doing this means we'll also need to merge the setup.cfg data into the pyproject.toml file, or at least the relevant config items under [project].

[pllim]

If you don't want pyproject.toml , you can achieve the same effect with just setup.cfg (deprecated but should still work)

[pllim]

I guess I'll leave it up to you two if this PR is okay as is or more changes needed. Thanks!

[jeffjennings]

As I said, my focus here is not to rewrite the setup files, it is an atomic change to fix downstream issues in getting the learn website to build. I have opened #37 to update the setup files. Please approve this so I can focus on the higher priority of the learn website.

[pllim]

I disabled auto merge because I have questions. Thanks!