Allows reading TMY data from a Path or file-like object

[jerluc]

• Related to Deprecations Tracker #2396
• I am familiar with the contributing guidelines
• Tests added
• Updates entries in docs/sphinx/source/reference for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

Per some related discussion in #2396, this adds support for pvlib.iotools.read_tmy3 to accept either a str, PathLike, or file-like object (text-only) as input. This patch reuses the _file_context_manager helper to remain consistent with how pvlib handles normalizing str/PathLike/file-like objects, while also introducing a minor backward-compatible improvement to the helper.

[jerluc]

For the maintainers: I think the checklist item to add a description to the "What's new" file is a step for once a version number is determined, but let me know if that's not the case and I can follow up!

[AdamRJensen]

Author

@jerluc We always have a tentative version, so you can add the Whatsnew entry here.

[jerluc]

@jerluc We always have a tentative version, so you can add the Whatsnew entry here.

Thanks for the pointer @AdamRJensen! Just added a note about this change in 8181548 and Sphinx output looks sane to me locally.

[AdamRJensen]

Suggested change

	tmy.read_tmy3(f, map_variables=False)
	tmy.read_tmy3(f, map_variables=False)
	assert 'GHI source' in data.columns

I suggest adding a simple assertion to make sure that the dataframe actually contains something.

[jerluc]

Thanks for the suggestion @AdamRJensen (maybe I should've read the test just below 😆). I've added it in 970688e, in addition to a check for the parsed data being 8760 rows, which I believe is correct for TMY3.

[kandersolar]

Thanks @jerluc!