API: Allow non-tuples in pandas.merge by TomAugspurger · Pull Request #34810 · pandas-dev/pandas (original) (raw)

It's easy to do it with a warning, so I would also just do that.

@TomAugspurger if we don't want to have it set-specific, could also do if not is_list_like(suffixes, allow_sets=False), although in practice that might give the same.