CLN: Make Series._values match Index._values

pandas/core/apply.py

@@ -278,7 +278,9 @@ def apply_standard(self):
         if (
             self.result_type in ["reduce", None]
             and not self.dtypes.apply(is_extension_array_dtype).any()
-            # Disallow complex_internals since libreduction shortcut
+            # Disallow dtypes that have blocks backed by EAs
+            and not self.dtypes.apply(lambda x: x.kind in ["m", "M"]).any()
+            # Disallow MultiIndex since libreduction shortcut
             #  cannot handle MultiIndex
             and not isinstance(self.agg_axis, ABCMultiIndex)
         ):

pandas/core/base.py

@@ -1265,6 +1265,10 @@ def unique(self):
         if hasattr(values, "unique"):
 
             result = values.unique()
+            if self.dtype.kind in ["m", "M"] and isinstance(self, ABCSeries):
+                # GH#31182 Series._values returns EA, unpack for backward-compat
+                if getattr(self.dtype, "tz", None) is None:
+                    result = np.asarray(result)
         else:
             result = unique1d(values)
 

pandas/core/internals/blocks.py

@@ -12,6 +12,7 @@
 import pandas._libs.internals as libinternals
 from pandas._libs.tslibs import Timedelta, conversion
 from pandas._libs.tslibs.timezones import tz_compare
+from pandas.util._decorators import cache_readonly
 from pandas.util._validators import validate_bool_kwarg
 
 from pandas.core.dtypes.cast import (
@@ -220,6 +221,10 @@ def array_values(self) -> ExtensionArray:
         """
         The array that Series.array returns. Always an ExtensionArray.
         """
+        return self._ea_values
+
+    @cache_readonly
+    def _ea_values(self) -> ExtensionArray:
         return PandasArray(self.values)
 
     def get_values(self, dtype=None):
@@ -2138,6 +2143,16 @@ def get_values(self, dtype=None):
             return result.reshape(self.values.shape)
         return self.values
 
+    def array_values(self):
+        return self._ea_values
+
+    def internal_values(self):
+        return self._ea_values
+
+    @cache_readonly
+    def _ea_values(self):
+        return self._holder._simple_new(self.values)
+
 
 class DatetimeBlock(DatetimeLikeBlockMixin, Block):
     __slots__ = ()
@@ -2260,9 +2275,6 @@ def set(self, locs, values):
     def external_values(self):
         return np.asarray(self.values.astype("datetime64[ns]", copy=False))
 
-    def array_values(self) -> ExtensionArray:
-        return DatetimeArray._simple_new(self.values)
-
 
 class DatetimeTZBlock(ExtensionBlock, DatetimeBlock):
     """ implement a datetime64 block with a tz attribute """
@@ -2271,6 +2283,7 @@ class DatetimeTZBlock(ExtensionBlock, DatetimeBlock):
     is_datetimetz = True
     is_extension = True
 
+    internal_values = Block.internal_values
     _can_hold_element = DatetimeBlock._can_hold_element
     to_native_types = DatetimeBlock.to_native_types
     fill_value = np.datetime64("NaT", "ns")
@@ -2520,9 +2533,6 @@ def to_native_types(self, slicer=None, na_rep=None, quoting=None, **kwargs):
     def external_values(self):
         return np.asarray(self.values.astype("timedelta64[ns]", copy=False))
 
-    def array_values(self) -> ExtensionArray:
-        return TimedeltaArray._simple_new(self.values)
-
 
 class BoolBlock(NumericBlock):
     __slots__ = ()

pandas/core/series.py

@@ -515,8 +515,9 @@ def _values(self):
         ----------- | ------------- | ------------- | ------------- | --------------- |
         Numeric     | ndarray       | ndarray       | PandasArray   | ndarray         |
         Category    | Categorical   | Categorical   | Categorical   | ndarray[int]    |
-        dt64[ns]    | ndarray[M8ns] | ndarray[M8ns] | DatetimeArray | ndarray[M8ns]   |
+        dt64[ns]    | ndarray[M8ns] | DatetimeArray | DatetimeArray | ndarray[M8ns]   |
         dt64[ns tz] | ndarray[M8ns] | DatetimeArray | DatetimeArray | ndarray[M8ns]   |
+        td64[ns]    | ndarray[m8ns] | TimedeltaArray| ndarray[m8bs] | ndarray[m8ns]   |
         Period      | ndarray[obj]  | PeriodArray   | PeriodArray   | ndarray[int]    |
         Nullable    | EA            | EA            | EA            | ndarray         |
 

pandas/tests/indexes/datetimes/test_tools.py

@@ -1583,7 +1583,7 @@ def test_string_na_nat_conversion(self, cache):
         for i in range(5):
             x = series[i]
             if isna(x):
-                expected[i] = iNaT
+                expected[i] = pd.NaT
             else:
                 expected[i] = to_datetime(x, cache=cache)
 

pandas/tests/reductions/test_reductions.py

@@ -316,7 +316,12 @@ def test_invalid_td64_reductions(self, opname):
         )
         td = s.diff()
 
-        msg = "reduction operation '{op}' not allowed for this dtype"
+        msg = "|".join(
+            [
+                "reduction operation '{op}' not allowed for this dtype",
+                r"cannot perform {op} with type timedelta64\[ns\]",
+            ]
+        )
         msg = msg.format(op=opname)
 
         with pytest.raises(TypeError, match=msg):
@@ -648,7 +653,13 @@ def test_ops_consistency_on_empty(self, method):
         # timedelta64[ns]
         tdser = Series([], dtype="m8[ns]")
         if method == "var":
-            with pytest.raises(TypeError, match="operation 'var' not allowed"):
+            msg = "|".join(
+                [
+                    "operation 'var' not allowed",
+                    r"cannot perform var with type timedelta64\[ns\]",
+                ]
+            )
+            with pytest.raises(TypeError, match=msg):
                 getattr(tdser, method)()
         else:
             result = getattr(tdser, method)()