pandas (original) (raw)

As pointed in #7041, I prepared a PR to add factorize to IndexOpsMixin.

As a side benefit, Multiindex.from_arrays can preserve original DatetimeIndex.freq and tz. (Related to #3950 and #6606. These issues are not solved yet because these use different methods to create MultiIndex).

I would like to confirm following points before adding more tests.

What Index.factorize and Series.factorize should return as unique values, ndarray or Index? I think it should return Index to preserve DatetimeIndex attributes (freq and tz).
Is this should be added to api.rst?