xs on MultiIndex Does not Work For Series

[cancan101]

This works:

In [141]:

dates = pd.to_datetime(['2013-09-03', '2013-09-04', '2013-09-05'])
pd.concat({'A':pd.Series([1,3,4], index=dates), 'B':pd.Series([1,3,4], index=dates)}).to_frame().xs(key='2013-09-03', level=1)

   0
A  1
B  1

[2 rows x 1 columns]

but this does not:

In [142]:

dates = pd.to_datetime(['2013-09-03', '2013-09-04', '2013-09-05'])

pd.concat({'A':pd.Series([1,3,4], index=dates), 'B':pd.Series([1,3,4], index=dates)}).xs(key='2013-09-03', level=1)

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-142-06aba7d44961> in <module>()
      1 dates = pd.to_datetime(['2013-09-03', '2013-09-04', '2013-09-05'])
----> 2 pd.concat({'A':pd.Series([1,3,4], index=dates), 'B':pd.Series([1,3,4], index=dates)}).xs(key='2013-09-03', level=1)

/usr/lib64/python2.7/site-packages/pandas/core/series.py in _xs(self, key, axis, level, copy)
    437 
    438     def _xs(self, key, axis=0, level=None, copy=True):
--> 439         return self.__getitem__(key)
    440 
    441     xs = _xs

/usr/lib64/python2.7/site-packages/pandas/core/series.py in __getitem__(self, key)
    482     def __getitem__(self, key):
    483         try:
--> 484             result = self.index.get_value(self, key)
    485             if isinstance(result, np.ndarray):
    486                 return self._constructor(result,index=[key]*len(result)).__finalize__(self)

/usr/lib64/python2.7/site-packages/pandas/core/index.py in get_value(self, series, key)
   2294                     raise InvalidIndexError(key)
   2295                 else:
-> 2296                     raise e1
   2297             except Exception:  # pragma: no cover
   2298                 raise e1

KeyError: '2013-09-03'

[jreback]

hmm...should work...odd...marking as a bug

[cancan101]

I am running this on v0.13, so it might be fixed in master.

[jreback]

this is still present

of course when reporting pls give a try on master anyhow

[TomAugspurger]

Probably related: #5684

I think I took a shot at fixing it, but scared off by the indexing code :)

[jreback]

@TomAugspurger

#6259 should fix this issue; can you check if fixes the related; if so you want to add another commit with tests for that one

xs was pretty broken - too many special cases ; not a whole lot of tests though

[TomAugspurger]

@jreback that seems to have fixed it. Thanks!

[jreback]

gr8
do you want to add those tests on?