Closed
Description
Using a DataFrame of bools to mask some values in another dataframe works great:
In [84]: pd.DataFrame([[1,2],[3,4]]).mask(pd.DataFrame([[True,False],[False, True]]))
Out[84]:
0 1
0 NaN 2
1 3 NaN
but not if we try on a dataframe with a single index:
In [85]: pd.DataFrame([[1,2],]).mask(pd.DataFrame([[True,False],]))
AssertionError: Number of Block dimensions (1) must equal number of axes (2)