DOC: Should DataFrame.drop() accept a set for the columns , index and labels argument?

[Dr-Irv]

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/pandas-docs/stable/reference/api/pandas.DataFrame.drop.html

Documentation problem

The arguments labels, index and columns are documented as "single label or list-like". But a set is accepted:

import pandas as pd

df = pd.DataFrame({1: [2], 3: [4]})   # Fix is here
df = df.drop(columns={1})

The pandas source declaration in the typing declarations does not allow a set to be passed.

Suggested fix for documentation

Unclear.

Either we update the docs to say a set is allowed (and update the internal types), OR we add a check to see if a set is passed and raise an exception.

First raised as a pandas-stubs issue in pandas-dev/pandas-stubs#1008