Series.drop regression and unexpected behaviour · Issue #5248 · pandas-dev/pandas (original) (raw)

On 0.12 stable this works:

>>> s = pandas.Series([1,1,2],index=["one","one","two"])
>>> s.drop(["one"])
two    2
dtype: int64

but a singleton silently fails:

>>> s.drop("one")
one    1
one    1
two    2
dtype: int64

except when index is unique:

>>> s = pandas.Series([1,2],index=["one","two"])
>>> s.drop("one")
two    2
dtype: int64

according to the docs, the input to drop should be array like, so i'm not sure this should be permissible.

On head, with unique index, it matches, but with non-unique:

>>> pandas.__version__
'0.12.0-892-g6830600'
>>> s = pandas.Series([1,1,2],index=["one","one","two"])
>>> s2 = s.drop(["one"])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pandas/core/generic.py", line 1133, in drop
    return self.ix[tuple(slicer)]
  File "pandas/core/indexing.py", line 53, in __getitem__
    return self._getitem_tuple(key)
  File "pandas/core/indexing.py", line 558, in _getitem_tuple
    return self._multi_take(tup)
  File "pandas/core/indexing.py", line 598, in _multi_take
    raise self._exception
KeyError