Druid lookup type extraction failing in pandas

[ghulands]

When you have a druid lookup type column defined as

{
 "type": "extraction",
 "dimension": "coderizedColumn",
 "outputName": "prettyNameColumn",
 "outputType": "STRING",
 "extractionFn": {
   "type": "lookup",
   "dimension": "dimensionName",
   "outputName": "dimensionOutputName",
   "replaceMissingValueWith": "missing_value",
   "retainMissingValue": false,
   "lookup": {
     "type": "map",
     "map": {
       "Code1": "PrettyName1",
       "Code2": "PrettyName2",
     },
     "isOneToOne": false
   }
 }
}

When trying to query on it, superset now breaks with the following exception

2017-11-06 16:57:59,864:ERROR:root:"None of [[u'extractionFn', u'dimension', u'outputName', u'outputType', u'type']] are in the [index]"
Traceback (most recent call last):
 File "/app/.heroku/python/lib/python2.7/site-packages/superset/viz.py", line 275, in get_payload
   df = self.get_df()
 File "/app/.heroku/python/lib/python2.7/site-packages/superset/viz.py", line 98, in get_df
   self.results = self.datasource.query(query_obj)
 File "/app/.heroku/python/lib/python2.7/site-packages/superset/connectors/druid/models.py", line 1069, in query
   client=client, query_obj=query_obj, phase=2)
 File "/app/.heroku/python/lib/python2.7/site-packages/superset/connectors/druid/models.py", line 865, in get_query_str
   return self.run_query(client=client, phase=phase, **query_obj)
   qry['dimensions'], filters)
 File "/app/.heroku/python/lib/python2.7/site-packages/superset/connectors/druid/models.py", line 874, in _add_filter_from_pre_query_data
   f = Dimension(dim) == row[dim]
 File "/app/.heroku/python/lib/python2.7/site-packages/superset/connectors/druid/models.py", line 1006, in run_query
 File "/app/.heroku/python/lib/python2.7/site-packages/pandas/core/series.py", line 642, in __getitem__
   return self._get_with(key)
 File "/app/.heroku/python/lib/python2.7/site-packages/pandas/core/series.py", line 683, in _get_with
   return self.loc[key]
 File "/app/.heroku/python/lib/python2.7/site-packages/pandas/core/indexing.py", line 1328, in __getitem__
   return self._getitem_axis(key, axis=0)
 File "/app/.heroku/python/lib/python2.7/site-packages/pandas/core/indexing.py", line 1541, in _getitem_axis
   return self._getitem_iterable(key, axis=axis)
 File "/app/.heroku/python/lib/python2.7/site-packages/pandas/core/indexing.py", line 1081, in _getitem_iterable
   self._has_valid_type(key, axis)
 File "/app/.heroku/python/lib/python2.7/site-packages/pandas/core/indexing.py", line 1418, in _has_valid_type
   (key, self.obj._get_axis_name(axis)))
KeyError: "None of [[u'extractionFn', u'dimension', u'outputName', u'outputType', u'type']] are in the [index]"

This broke in the 0.19 series of releases.

[kkalyan]

This #3920 should fix issue with dimension spec.