Groupby tuples by toobaz · Pull Request #18249 · pandas-dev/pandas (original) (raw)

Sorry for having missed #17996, where this could have been discussed, but this said I don't think we should treat specially the case of a MultiIndex (see the test I added with tuples as labels): we should just interpret what is not a list as a label, as the docs already state (although with some incoherence, which I tried to address).

While I was at it, I fixed a typo which made a test inserted in #17996 trivial.