Selection Issues
I am getting the following error when selecting multiple columns:
TypeError: unsupported operand type(s) for |: 'bool' and 'NotImplementedType'

Code:

``` sql
df.columns
```

Index([KeyNum, ServiceAddrID, ActionStatus, LDCServiceLocationSystemID, LDCCustomerSystemID, TurnOnDate, TurnOffDate, ...etc , dtype=object)

If I select any single column, I get no error.

``` sql
df['TurnOffDate']
```

Selecting multiple columns gives me the error above:

``` sql
df[['TurnOffDate', 'TurnOnDate']]
```

Here is more of the error message:

---

TypeError                                 Traceback (most recent call last)
<ipython-input-30-83763ede32b0> in <module>()
      4 # Filter the florida accounts
      5 #fl = df.loc[cols][df['State'] == 'FL']
----> 6 df[['TurnOffDate', 'TurnOnDate']]
      7 # Rename second 'ServiceAddrID'
      8 #fl.columns.values[11] = 'SAID'

C:\Python27\lib\site-packages\pandas\core\frame.pyc in **getitem**(self, key)
   1882         if isinstance(key, (np.ndarray, list)):
   1883             # either boolean or fancy integer index
-> 1884             return self._getitem_array(key)
   1885         elif isinstance(key, DataFrame):
   1886             return self._getitem_frame(key)

C:\Python27\lib\site-packages\pandas\core\frame.pyc in _getitem_array(self, key)
   1914             return self.take(indexer, axis=0, convert=False)
   1915         else:
-> 1916             indexer = self.ix._convert_to_indexer(key, axis=1)
   1917             return self.take(indexer, axis=1, convert=True)
   1918 

C:\Python27\lib\site-packages\pandas\core\indexing.pyc in _convert_to_indexer(self, obj, axis)
    575                             if not to_or.any():
    576                                 raise KeyError('%s not in index' % str(x))
--> 577                             mask |= to_or
    578 
    579                         indexer = check = mask.nonzero()[0]

TypeError: unsupported operand type(s) for |: 'bool' and 'NotImplementedType'
