pandas.test() produces many PytestUnknownMarkWarning

[TomAugspurger]

For example

>>> import pandas
>>> pandas.test(['-k', 'TestPDApi'])

Has many warnings like

Envs/dask-dev/lib/python3.7/site-packages/pandas/tests/series/indexing/test_datetime.py:121
  /Users/taugspurger/Envs/dask-dev/lib/python3.7/site-packages/pandas/tests/series/indexing/test_datetime.py:121: PytestUnknownMarkWarning: Unknown pytest.mark.slow - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    @pytest.mark.slow

Envs/dask-dev/lib/python3.7/site-packages/pandas/tests/series/methods/test_rank.py:559
  /Users/taugspurger/Envs/dask-dev/lib/python3.7/site-packages/pandas/tests/series/methods/test_rank.py:559: PytestUnknownMarkWarning: Unknown pytest.mark.single - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    @pytest.mark.single

Envs/dask-dev/lib/python3.7/site-packages/pandas/tests/series/methods/test_rank.py:560
  /Users/taugspurger/Envs/dask-dev/lib/python3.7/site-packages/pandas/tests/series/methods/test_rank.py:560: PytestUnknownMarkWarning: Unknown pytest.mark.high_memory - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    @pytest.mark.high_memory

We register these:

pandas/setup.cfg

Lines 56 to 62 in 5da500a

	markers =
	single: mark a test as single cpu only
	slow: mark a test as slow
	network: mark a test as network
	db: tests requiring a database (mysql or postgres)
	high_memory: mark a test as a high-memory only
	clipboard: mark a pd.read_clipboard test

. But the setup.cfg is perhaps not included with the distribution, and so the registered marks aren't available perhaps? Is there anyone more familiar with pytest who knows what we should be doing here?

[WillAyd]

Hmm this might be important for mypy as well as all of our config is contained in that file. Maybe we should just distribute that with the package?

[TomAugspurger]

I'm not sure that distributing the setup.cfg is an option. It's not clear where it would be placed (it's not in the pandas package source directory), and I don't know how we would get pytest to read it. It seems like if we want users to have these marks, we'd need to treat them like a custom plugin: https://docs.pytest.org/en/latest/writing_plugins.html#registering-custom-markers

[jbrockmendel]

Just tried this and I don't see the warnings from the OP, do see

========================================================================== warnings summary ==========================================================================
/usr/local/lib/python3.8/site-packages/_pytest/config/__init__.py:1040
  /usr/local/lib/python3.8/site-packages/_pytest/config/__init__.py:1040: PytestAssertRewriteWarning: Module already imported so cannot be rewritten: hypothesis
    self._mark_plugins_for_rewrite(hook)

/usr/local/lib/python3.8/site-packages/aiohttp/helpers.py:107
  /usr/local/lib/python3.8/site-packages/aiohttp/helpers.py:107: DeprecationWarning: "@coroutine" decorator is deprecated since Python 3.8, use "async def" instead
    def noop(*args, **kwargs):  # type: ignore

-- Docs: https://docs.pytest.org/en/stable/warnings.html
==================================================== 2 passed, 2 skipped, 74034 deselected, 2 warnings in 36.24s =====================================================

[TomAugspurger]

This was fixed in #35146, sorry.

Those other workings are from other packages, so likely nothing we can do about it.