Selecting columns from a HDFStore with a MultiIndex fails #3748
Description
Using the example from the docs here: http://pandas.pydata.org/pandas-docs/dev/io.html#storing-multi-index-dataframes but specifying the 'columns' in [1219] keyword when selecting:
store.select('df_mi', columns=['A', 'B'])
leads to the failure below. The original example works, as does selecting columns with a standard index. I'm on a fairly recent master (~1 week) and Python 3.3. Hope this is not expected and I did not miss an issue, I did search for a bit.
KeyError Traceback (most recent call last)
<ipython-input-67-678a9c77d998> in <module>()
----> 1 store.select('df_mi', columns=['A', 'B'])
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/io/pytables.py in select(self, key, where, start, stop, columns, iterator, chunksize, **kwargs)
413 return TableIterator(func, nrows=s.nrows, start=start, stop=stop, chunksize=chunksize)
414
--> 415 return TableIterator(func, nrows=s.nrows, start=start, stop=stop).get_values()
416
417 def select_as_coordinates(self, key, where=None, start=None, stop=None, **kwargs):
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/io/pytables.py in get_values(self)
931
932 def get_values(self):
--> 933 return self.func(self.start, self.stop)
934
935
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/io/pytables.py in func(_start, _stop)
408 # what we are actually going to do for a chunk
409 def func(_start, _stop):
--> 410 return s.read(where=where, start=_start, stop=_stop, columns=columns, **kwargs)
411
412 if iterator or chunksize is not None:
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/io/pytables.py in read(self, *args, **kwargs)
3142 def read(self, *args, **kwargs):
3143 df = super(AppendableMultiFrameTable, self).read(*args, **kwargs)
-> 3144 df.set_index(self.levels, inplace=True)
3145 return df
3146
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/core/frame.py in set_index(self, keys, drop, append, inplace, verify_integrity)
2795 names.append(None)
2796 else:
-> 2797 level = frame[col].values
2798 names.append(col)
2799 if drop:
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/core/frame.py in __getitem__(self, key)
1992 else:
1993 # get column
-> 1994 return self._get_item_cache(key)
1995
1996 def _getitem_slice(self, key):
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/core/generic.py in _get_item_cache(self, item)
572 return cache[item]
573 except Exception:
--> 574 values = self._data.get(item)
575 res = self._box_item_values(item, values)
576 cache[item] = res
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/core/internals.py in get(self, item)
1646
1647 def get(self, item):
-> 1648 _, block = self._find_block(item)
1649 return block.get(item)
1650
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/core/internals.py in _find_block(self, item)
1773
1774 def _find_block(self, item):
-> 1775 self._check_have(item)
1776 for i, block in enumerate(self.blocks):
1777 if item in block:
/home/xxx/anaconda/envs/py33/lib/python3.3/site-packages/pandas-0.12.0.dev_2bd1cf8-py3.3-linux-x86_64.egg/pandas/core/internals.py in _check_have(self, item)
1780 def _check_have(self, item):
1781 if item not in self.items:
-> 1782 raise KeyError('no item named %s' % com.pprint_thing(item))
1783
1784 def reindex_axis(self, new_axis, method=None, axis=0, copy=True):
KeyError: 'no item named foo'