[API/ERR]: Better error message on unstack with non-unique index names · Issue #6729 · pandas-dev/pandas (original) (raw)

df = pd.DataFrame([1,1], index=pd.MultiIndex.from_tuples([('a', 'a'), ('a', 'b')], names=['i1', 'i1']))

In [5]: df.unstack('i1')

...

KeyError: 'Level i1 not found'

I can do a PR later.

Should also probably be a ValueError instead of a KeyError.