updates

pandas/core/dtypes/base.py

@@ -175,7 +175,9 @@ def type(self):
         """The scalar type for the array, e.g. ``int``
 
         It's expected ``ExtensionArray[item]`` returns an instance
-        of ``ExtensionDtype.type`` for scalar ``item``.
+        of ``ExtensionDtype.type`` for scalar ``item``, assuming
+        that value is valid (not NA). NA values do not need to be
+        instances of `type`.
         """
         raise AbstractMethodError(self)
 

pandas/core/dtypes/common.py

@@ -4,7 +4,7 @@
 from pandas.compat import (string_types, text_type, binary_type,
                            PY3, PY36)
 from pandas._libs import algos, lib
-from pandas._libs.tslibs import conversion, Period
+from pandas._libs.tslibs import conversion, Period, Timestamp
 from pandas._libs.interval import Interval
 
 from pandas.core.dtypes.dtypes import (
@@ -1915,7 +1915,7 @@ def _get_dtype_type(arr_or_dtype):
         if is_categorical_dtype(arr_or_dtype):
             return CategoricalDtypeType
         elif is_datetime64tz_dtype(arr_or_dtype):
-            return DatetimeTZDtypeType
+            return Timestmap
         elif is_period_dtype(arr_or_dtype):
             return Period
         elif is_interval_dtype(arr_or_dtype):

pandas/core/dtypes/dtypes.py

@@ -4,7 +4,7 @@
 import numpy as np
 from pandas import compat
 from pandas.core.dtypes.generic import ABCIndexClass, ABCCategoricalIndex
-from pandas._libs.tslibs import Period, NaT
+from pandas._libs.tslibs import Period, NaT, Timestamp
 from pandas._libs.interval import Interval
 
 from .base import ExtensionDtype, _DtypeOpsMixin
@@ -471,13 +471,6 @@ def _is_boolean(self):
         return is_bool_dtype(self.categories)
 
 
-class DatetimeTZDtypeType(type):
-    """
-    the type of DatetimeTZDtype, this metaclass determines subclass ability
-    """
-    pass
-
-
 class DatetimeTZDtype(PandasExtensionDtype):
 
     """
@@ -487,7 +480,7 @@ class DatetimeTZDtype(PandasExtensionDtype):
     THIS IS NOT A REAL NUMPY DTYPE, but essentially a sub-class of
     np.datetime64[ns]
     """
-    type = DatetimeTZDtypeType
+    type = Timestamp
     kind = 'M'
     str = '|M8[ns]'
     num = 101

pandas/tests/dtypes/test_common.py

@@ -605,10 +605,10 @@ def test__get_dtype_fails(input_param):
     (pd.DatetimeIndex([1, 2]), np.datetime64),
     (pd.DatetimeIndex([1, 2]).dtype, np.datetime64),
     ('<M8[ns]', np.datetime64),
-    (pd.DatetimeIndex([1, 2], tz='Europe/London'), com.DatetimeTZDtypeType),
+    (pd.DatetimeIndex([1, 2], tz='Europe/London'), pd.Timestmap),
     (pd.DatetimeIndex([1, 2], tz='Europe/London').dtype,
-     com.DatetimeTZDtypeType),
-    ('datetime64[ns, Europe/London]', com.DatetimeTZDtypeType),
+     pd.Timestmap),
+    ('datetime64[ns, Europe/London]', pd.Timestmap),
     (pd.SparseSeries([1, 2], dtype='int32'), np.int32),
     (pd.SparseSeries([1, 2], dtype='int32').dtype, np.int32),
     (PeriodDtype(freq='D'), pd.Period),