DOC: groupby by argument types

[amotzop]

Pandas version checks

• I have checked that the issue still exists on the latest versions of the docs on main here

Location of the documentation

https://pandas.pydata.org/docs/dev/reference/api/pandas.DataFrame.groupby.html
https://pandas.pydata.org/docs/dev/reference/api/pandas.Series.groupby.html

Documentation problem

I think there are a couple of possible types for the by parameter of the groupby functions that are missing from the documentation:

• pd.Grouper (as seen in the documentation of Grouper)
• list of functions/list of mappings.

Suggested fix for documentation

Just add these types to the possible typings:
by: mapping, function, label, pd.Grouper or list of such

[paradox-lab]

I would like to take this.

[amotzop]

Is there a reason the updated typing doesn't contain list of functions/mapping/pd.Grouper? From the code it seems to be supported?