added tests for the test_groupby_dropna.py

[hhheidi]

• closes BUG: dropna=False not respected for groupby aggs on result of concatenated dataframes #46783

[pep8speaks]

Hello @hhheidi! Thanks for opening this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file pandas/tests/groupby/test_groupby_dropna.py:

Line 352:1: E302 expected 2 blank lines, found 1
Line 363:38: E231 missing whitespace after ','
Line 380:45: W292 no newline at end of file

[phofl]

Can you run pre-commit locally? This gets rid of the Pep8 stuff.

One of your new tests is failing

Edit: Is the behavior already fixed on master?

[github-actions]

This pull request is stale because it has been open for thirty days with no activity. Please update and respond to this comment if you're still interested in working on this.

[mroeschke]

Thanks for the pull request, but it appears to be stale and is failing a lot of the CI checks. If interested in continuing, please fix the formatting and tests failures locally and we can reopen.