Thanks Dave for closing. I would recommend in the future if you have packaging questions to bring them to packaging problems repo as indicated at https://packaging.python.org/support/#how-to-get-support.

Glad to hear that `as_file` promised to do what you need. Do be aware that it doesn't yet support a directory of files (only individual files), a known deficiency (https://github.com/python/importlib_resources/issues/228).

I don't have any good advice on separating Python and non-Python code in your package. You're right that the current interfaces for supporting package resources are specifically designed around resources in a Python package (aka package_data).

I agree that there may not be a robust way to locate "data_files". It sounds like you have a use-case that's not well served by the current implementation. I'd recommend to file a report describing a detailed minimal example of the use-case you have and what you'd like to see (in packaging-problems; maybe search if someone's already reported). One thing you'll want to answer is where do you expect these files to be installed if not in the python package?

Thanks and good luck!