MultiIndex partial slicing error #1352
Description
In [10]: idx = MultiIndex(labels=[[0,0,0],[0,1,1],[1,0,1]],levels=[['a','b'],['x','y'],['p','q']])
In [11]: df = DataFrame(np.random.rand(3,2),index=idx)
In [12]: df.ix[('a','y')]
Out[12]:
0 1
p 0.788191 0.781931
q 0.566332 0.486645
In [13]: df[('a','y')]
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
/home/adam/code/qplib/<ipython-input-13-d3c63a882cb1> in <module>()
----> 1 df[('a','y')]
/home/adam/code/pandas/pandas/core/frame.pyc in __getitem__(self, key)
1655 return self._getitem_multilevel(key)
1656 else:
-> 1657 return self._get_item_cache(key)
1658
1659 def _getitem_array(self, key):
/home/adam/code/pandas/pandas/core/generic.pyc in _get_item_cache(self, item)
472 except Exception:
473 try:
--> 474 values = self._data.get(item)
475 res = self._box_item_values(item, values)
476 cache[item] = res
/home/adam/code/pandas/pandas/core/internals.pyc in get(self, item)
756
757 def get(self, item):
--> 758 _, block = self._find_block(item)
759 return block.get(item)
760
/home/adam/code/pandas/pandas/core/internals.pyc in _find_block(self, item)
846
847 def _find_block(self, item):
--> 848 self._check_have(item)
849 for i, block in enumerate(self.blocks):
850 if item in block:
/home/adam/code/pandas/pandas/core/internals.pyc in _check_have(self, item)
853 def _check_have(self, item):
854 if item not in self.items:
--> 855 raise KeyError('no item named %s' % str(item))
856
857 def reindex_axis(self, new_axis, method=None, axis=0, copy=True):
KeyError: "no item named ('a', 'y')"
In [14]: df.ix[('a','y'),:]
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
/home/adam/code/qplib/<ipython-input-14-19a9d60d6a3b> in <module>()
----> 1 df.ix[('a','y'),:]
/home/adam/code/pandas/pandas/core/indexing.pyc in __getitem__(self, key)
31 pass
/home/adam/code/pandas/pandas/core/indexing.pyc in _getitem_tuple(self, tup)
96 def _getitem_tuple(self, tup):
97 try:
---> 98 return self._getitem_lowerdim(tup)
99 except IndexingError:
100 pass
/home/adam/code/pandas/pandas/core/indexing.pyc in _getitem_lowerdim(self, tup)
165 if isinstance(ax0, MultiIndex):
166 try:
--> 167 return self._get_label(tup, axis=0)
168 except TypeError:
169 # slices are unhashable
/home/adam/code/pandas/pandas/core/indexing.pyc in _get_label(self, label, axis)
39 return self.obj.xs(label, axis=axis, copy=False)
40 except Exception:
---> 41 return self.obj.xs(label, axis=axis, copy=True)
42
43 def _slice(self, obj, axis=0):
/home/adam/code/pandas/pandas/core/frame.pyc in xs(self, key, axis, level, copy)
1894 index = self.index
1895 if isinstance(index, MultiIndex):
-> 1896 loc, new_index = self.index.get_loc_level(key)
1897 else:
1898 loc = self.index.get_loc(key)
/home/adam/code/pandas/pandas/core/index.pyc in get_loc_level(self, key, level)
2000 for i, k in enumerate(key):
2001 if not isinstance(k, slice):
-> 2002 k = self._get_level_indexer(k, level=i)
2003 if isinstance(k, slice):
2004 # everything
/home/adam/code/pandas/pandas/core/index.pyc in _get_level_indexer(self, key, level)
2030 def _get_level_indexer(self, key, level=0):
2031 level_index = self.levels[level]
-> 2032 loc = level_index.get_loc(key)
2033 labels = self.labels[level]
2034
/home/adam/code/pandas/pandas/core/index.pyc in get_loc(self, key)
623 loc : int
624 """
--> 625 return self._engine.get_loc(key)
626
627 def get_value(self, series, key):
/home/adam/code/pandas/pandas/lib.so in pandas.lib.IndexEngine.get_loc (pandas/src/tseries.c:112968)()
/home/adam/code/pandas/pandas/lib.so in pandas.lib.IndexEngine.get_loc (pandas/src/tseries.c:112835)()
/home/adam/code/pandas/pandas/lib.so in pandas.lib.PyObjectHashTable.get_item (pandas/src/tseries.c:22698)()
/home/adam/code/pandas/pandas/lib.so in pandas.lib.PyObjectHashTable.get_item (pandas/src/tseries.c:22652)()
KeyError: ('a', 'y')