@tomvothecoder thank you for reporting this. I am having trouble reproducing this, probably due to my lack of experience enabling deprecation warnings in python.

Things I have tried (from https://docs.python.org/3/library/warnings.html and elsewhere), using python 3.11:

• Importing esmpy with python started normally
• Importing esmpy with python started with python -Wd
• Importing esmpy with python started with python -W "default::DeprecationWarning"
• Importing esmpy with python started with python -Walways

None of these led to the deprecation warnings you noted above. Would you be able to describe how to reproduce these warnings?

Hi @billsacks, thanks for getting back about this. I'll try to provide a minimum reproducible example along with the version of esmpy that is in my conda env soon.

I tried your commands and also can't reproduce the issue. I only notice it in my repo's test suite.

Here is extra info that might be helpful.

Conda environment:

esmf                      8.4.2           mpi_mpich_h742b71d_100    conda-forge
esmpy                     8.4.2              pyhc1e730c_1    conda-forge
...
python                    3.11.4          hab00c5b_0_cpython    conda-forge
...
xesmf                     0.7.1              pyhd8ed1ab_0    conda-forge

Warnings

../../miniconda3/envs/xcdat_dev/lib/python3.11/site-packages/esmpy/__init__.py:106
  /home/vo13/miniconda3/envs/xcdat_dev/lib/python3.11/site-packages/esmpy/__init__.py:106: DeprecationWarning: Implicit None on return values is deprecated and will raise KeyErrors.
    __author__ = msg["Author"]

../../miniconda3/envs/xcdat_dev/lib/python3.11/site-packages/esmpy/__init__.py:107
  /home/vo13/miniconda3/envs/xcdat_dev/lib/python3.11/site-packages/esmpy/__init__.py:107: DeprecationWarning: Implicit None on return values is deprecated and will raise KeyErrors.
    __homepage__ = msg["Home-page"]

../../miniconda3/envs/xcdat_dev/lib/python3.11/site-packages/esmpy/__init__.py:108
  /home/vo13/miniconda3/envs/xcdat_dev/lib/python3.11/site-packages/esmpy/__init__.py:108: DeprecationWarning: Implicit None on return values is deprecated and will raise KeyErrors.
    __obsoletes__ = msg["obsoletes"]

Related code lines:

What I think is causing the issue

"Author", "Home-page" and "obsoletes" aren't set in pyproject.toml but is being referenced in esmpy.__init__.py.

Minimum example:

import importlib.metadata as ilm

msg = ilm.metadata("esmpy")

print(msg.__dict__)
# {'policy': Compat32(), '_headers': [('Metadata-Version', '2.1'), ('Name', 'esmpy'), ('Version', '8.4.2'), ('Summary', 'ESMF Python interface'), ('Maintainer-email', 'ESMF Core Team <[email protected]>'), ('License', 'University of Illinois-NCSA'), ('Requires-Python', '>=3.7'), ('License-File', 'LICENSE'), ('Requires-Dist', 'numpy'), ('Requires-Dist', 'importlib-metadata ; python_version < "3.8"'), ('Provides-Extra', 'testing'), ('Requires-Dist', "pytest ; extra == 'testing'"), ('Requires-Dist', "pytest-json-report ; extra == 'testing'")], '_unixfrom': None, '_payload': '', '_charset': None, 'preamble': None, 'epilogue': None, 'defects': [], '_default_type': 'text/plain'}


msg["Author"]  # Returns None
msg["Home-page"]  # Returns None
msg["obsoletes"]  # Returns None

Related issues from other repos

• DeprecationWarning: Implicit None on return values is deprecated and will raise KeyErrors. pypa/twine#977
• pydoc emits deprecation warnings about package metadata python/cpython#103624

Thank you for your very detailed information, @tomvothecoder ! As far as I can tell, these three attributes aren't needed for anything, so I have simply removed them. Please let me know if you run into any additional, related issues.

We're about to have our 8.5.0 release freeze; I'm not sure if the fix will make it into the 8.5.0 release or will need to wait for 8.6.0.

@billsacks cheers very much! Has the fix made it to 8.5.0 or 8.6.0? Many thanks 🍺

This fix is in 8.5.0 and all following versions.

This fix is in 8.5.0 and all following versions.

brilliant, many thanks @billsacks 🍺