Add get_values override to CategoricalIndex, and remove previous workaround

Author: evanpw

doc/source/whatsnew/v0.16.2.txt

@@ -66,7 +66,9 @@ Bug Fixes
 - Bug in getting timezone data with ``dateutil`` on various platforms ( :issue:`9059`, :issue:`8639`, :issue:`9663`, :issue:`10121`)
 - Bug in display datetimes with mixed frequencies uniformly; display 'ms' datetimes to the proper precision. (:issue:`10170`)
 
-- Bung in ``Series`` arithmetic methods may incorrectly hold names (:issue:`10068`)
+- Bun in ``Series`` arithmetic methods may incorrectly hold names (:issue:`10068`)
+
+- Bug in ``GroupBy.get_group`` when grouping on multiple keys, one of which is categorical. (:issue:`10132`)
 
 - Bug in ``DatetimeIndex`` and ``TimedeltaIndex`` names are lost after timedelta arithmetics ( :issue:`9926`)
 

doc/source/whatsnew/v0.17.0.txt

@@ -57,13 +57,3 @@ Performance Improvements
 
 Bug Fixes
 ~~~~~~~~~
-
-- Bug in ``Categorical`` repr with ``display.width`` of ``None`` in Python 3 (:issue:`10087`)
-
-
-- Bug in ``Timestamp``'s' ``microsecond``, ``quarter``, ``dayofyear``, ``week`` and ``daysinmonth`` properties return ``np.int`` type, not built-in ``int``. (:issue:`10050`)
-- Bug in ``GroupBy.get_group`` when grouping on multiple keys, one of which is categorical. (:issue:`10132`)
-- Bug in ``NaT`` raises ``AttributeError`` when accessing to ``daysinmonth``, ``dayofweek`` properties. (:issue:`10096`)
-
-
-

pandas/core/groupby.py

@@ -1301,18 +1301,11 @@ def apply(self, f, data, axis=0):
     @cache_readonly
     def indices(self):
         """ dict {group name -> group indices} """
-
-        def extract_values(x):
-            if isinstance(x, CategoricalIndex):
-                return x.values.get_values()
-            else:
-                return _values_from_object(x)
-
         if len(self.groupings) == 1:
             return self.groupings[0].indices
         else:
             label_list = [ping.labels for ping in self.groupings]
-            keys = [extract_values(ping.group_index) for ping in self.groupings]
+            keys = [_values_from_object(ping.group_index) for ping in self.groupings]
             return _get_indices_dict(label_list, keys)
 
     @property

pandas/core/index.py

@@ -2964,6 +2964,10 @@ def values(self):
         """ return the underlying data, which is a Categorical """
         return self._data
 
+    def get_values(self):
+        """ return the underlying data as an ndarray """
+        return self._data.get_values()
+
     @property
     def codes(self):
         return self._data.codes