REF: trimmed-diff version of pandas-dev#40149

Author: jbrockmendel

pandas/core/array_algos/take.py

@@ -16,10 +16,7 @@
 from pandas._typing import ArrayLike
 
 from pandas.core.dtypes.cast import maybe_promote
-from pandas.core.dtypes.common import (
-    ensure_platform_int,
-    is_1d_only_ea_obj,
-)
+from pandas.core.dtypes.common import ensure_platform_int
 from pandas.core.dtypes.missing import na_value_for_dtype
 
 from pandas.core.construction import ensure_wrapped_if_datetimelike
@@ -94,14 +91,12 @@ def take_nd(
 
     if not isinstance(arr, np.ndarray):
         # i.e. ExtensionArray,
-        # includes for EA to catch DatetimeArray, TimedeltaArray
-        if not is_1d_only_ea_obj(arr):
-            # i.e. DatetimeArray, TimedeltaArray
+        if arr.ndim == 2:
+            # e.g. DatetimeArray, TimedeltArray
             arr = cast("NDArrayBackedExtensionArray", arr)
             return arr.take(
                 indexer, fill_value=fill_value, allow_fill=allow_fill, axis=axis
             )
-
         return arr.take(indexer, fill_value=fill_value, allow_fill=allow_fill)
 
     arr = np.asarray(arr)

pandas/core/frame.py

@@ -99,7 +99,6 @@
     ensure_platform_int,
     infer_dtype_from_object,
     is_1d_only_ea_dtype,
-    is_1d_only_ea_obj,
     is_bool_dtype,
     is_dataclass,
     is_datetime64_any_dtype,
@@ -138,11 +137,7 @@
 )
 from pandas.core.array_algos.take import take_2d_multi
 from pandas.core.arraylike import OpsMixin
-from pandas.core.arrays import (
-    DatetimeArray,
-    ExtensionArray,
-    TimedeltaArray,
-)
+from pandas.core.arrays import ExtensionArray
 from pandas.core.arrays.sparse import SparseFrameAccessor
 from pandas.core.construction import (
     extract_array,
@@ -855,28 +850,6 @@ def _can_fast_transpose(self) -> bool:
         # TODO(EA2D) special case would be unnecessary with 2D EAs
         return not is_1d_only_ea_dtype(dtype)
 
-    @property
-    def _values_compat(self) -> np.ndarray | DatetimeArray | TimedeltaArray:
-        """
-        Analogue to ._values that may return a 2D ExtensionArray.
-        """
-        mgr = self._mgr
-        if isinstance(mgr, ArrayManager):
-            return self._values
-
-        blocks = mgr.blocks
-        if len(blocks) != 1:
-            return self._values
-
-        arr = blocks[0].values
-        if arr.ndim == 1:
-            # non-2D ExtensionArray
-            return self._values
-
-        # more generally, whatever we allow in NDArrayBackedExtensionBlock
-        arr = cast("DatetimeArray | TimedeltaArray", arr)
-        return arr.T
-
     # ----------------------------------------------------------------------
     # Rendering Methods
 
@@ -3317,18 +3290,7 @@ def transpose(self, *args, copy: bool = False) -> DataFrame:
         # construct the args
 
         dtypes = list(self.dtypes)
-
-        if self._can_fast_transpose:
-            # Note: tests pass without this, but this improves perf quite a bit.
-            new_vals = self._values_compat.T
-            if copy:
-                new_vals = new_vals.copy()
-
-            result = self._constructor(new_vals, index=self.columns, columns=self.index)
-
-        elif (
-            self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
-        ):
+        if self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0]):
             # We have EAs with the same dtype. We can preserve that dtype in transpose.
             dtype = dtypes[0]
             arr_type = dtype.construct_array_type()
@@ -9765,9 +9727,8 @@ def func(values: np.ndarray):
 
         def blk_func(values, axis=1):
             if isinstance(values, ExtensionArray):
-                if not is_1d_only_ea_obj(values) and not isinstance(
-                    self._mgr, ArrayManager
-                ):
+                if values.ndim == 2:
+                    # i.e. DatetimeArray, TimedeltaArray
                     return values._reduce(name, axis=1, skipna=skipna, **kwds)
                 return values._reduce(name, skipna=skipna, **kwds)
             else:

pandas/tests/frame/methods/test_transpose.py

@@ -90,16 +90,3 @@ def test_transpose_get_view(self, float_frame):
         dft.values[:, 5:10] = 5
 
         assert (float_frame.values[5:10] == 5).all()
-
-    @td.skip_array_manager_invalid_test
-    def test_transpose_get_view_dt64tzget_view(self):
-        dti = date_range("2016-01-01", periods=6, tz="US/Pacific")
-        arr = dti._data.reshape(3, 2)
-        df = DataFrame(arr)
-        assert df._mgr.nblocks == 1
-
-        result = df.T
-        assert result._mgr.nblocks == 1
-
-        rtrip = result._mgr.blocks[0].values
-        assert np.shares_memory(arr._data, rtrip._data)