Creating series with multiindex from dict with tuple keys with None (original) (raw)

Code Sample

import pandas as pd

data1={(1, 2): 3, (4, None): 6}

s1 = pd.Series(data=data1)

data2={(1, 2): 3, (None, 5): 6}

s2 = pd.Series(data=data2)

Problem description

s1 has MultiIndex while s2 has Index of tuple just because the second element of the data2 has None as the first element of the key tuple.

s1 1 2 3.0 4 NaN NaN dtype: float64 s2 (1, 2) 3 (None, 5) 6 dtype: int64

Is this a bug? or is this how it's supposed to be?

FYI, both of mi1 and mi2 below yield MultiIndex as I expect.

mi1 = pd.MultiIndex.from_tuples([(1, 2), (4, None)]) mi2 = pd.MultiIndex.from_tuples([(1, 2), (None, 5)])