DOC: scripts/validate_docstrings.py should detect when the short summary span over multiple lines

[Moisan]

Code Sample, a copy-pastable example if possible

Take any docstring and write a short summary (the first line of the docstring) on multiple lines. Then test it with ./scripts/validate_docstrings.py pandas.DataFrame.my_method.

Problem description

As discussed in #22516 and in the documentation, the first line of the docstring should be a short summary and shouldn't take more than one line.

Expected Output

An error stating that the first line (the short summary) should not be more than one line long.

[WillAyd]

Hmm I think we have this generally covered and tested:

pandas/scripts/tests/test_validate_docstrings.py

Line 558 in e2e1a10

('BadSummaries', 'multi_line',

Isn't the first line in the linked PR a single line anyway? @datapythonista

[datapythonista]

Seems like before fixing the docstring to have a short summary, the script had the reported problem, as @Moisan showned here: https://gist.github.com/Moisan/5b349fddeea6f7ed83987673f7bde5de

[WillAyd]

Ah OK - I thought this was referring to the current state of the PR, which is now correct. That makes more sense :-)

[datapythonista]

@Moisan feel free to send a PR, you can use the beginning of your original docstring for the test that reproduces the error. I guess it has to do with the latex code, as in most cases the script works as expected.