Series.drop() with boolean index: inconsistent behaviour · Issue #8530 · pandas-dev/pandas (original) (raw)

The behaviour below occurs in versions '0.15.0rc1-21-g32c5016' and '0.14.1'.

When the label passed to the drop method of a Series is not in the index:
(a) if the index is not all booleans then an error is raised
(b) if the index is all booleans and has length > 1 then no error is raised; the original series is returned
(c) if the index is all booleans and has length == 1 then an error is raised

I propose that:

1. the difference between the behaviour in (a) and (b) should be documented
2. the behaviour in (c) should be changed to match that in (b)

Examples of current behaviour:
(a)

pd.Series([1, 1], index=['a', True]).drop(False) ValueError: labels [False] not contained in axis

(b)

pd.Series([1, 1], index=[True, True]).drop(False) True 1 True 1 dtype: int64

(c)

pd.Series([1], index=[True]).drop(False) ValueError: labels [False] not contained in axis