feedback

pandas/core/arrays/arrow/array.py

@@ -2160,7 +2160,9 @@ def interpolate(
         """
         # NB: we return type(self) even if copy=False
         if not self.dtype._is_numeric:
-            raise ValueError("Values must be numeric.")
+            raise NotImplementedError(
+                f"interpolate is not implemented for dtype={self.dtype}"
+            )
 
         if (
             not pa_version_under13p0

pandas/core/frame.py

@@ -6273,10 +6273,6 @@ class    max    type
             else:
                 to_insert = ((self.index, None),)
 
-            if len(new_obj.columns) == 0 and names:
-                target_dtype = Index(names).dtype
-                new_obj.columns = new_obj.columns.astype(target_dtype)
-
             multi_col = isinstance(self.columns, MultiIndex)
             for j, (lev, lab) in enumerate(to_insert, start=1):
                 i = self.index.nlevels - j

pandas/core/internals/blocks.py

@@ -2361,6 +2361,4 @@ def external_values(values: ArrayLike) -> ArrayLike:
         values.flags.writeable = False
 
     # TODO(CoW) we should also mark our ExtensionArrays as read-only
-    if isinstance(values, ExtensionArray):
-        ...  # this is why test_to_dict_of_blocks_item_cache fails
     return values

pandas/tests/frame/methods/test_astype.py

@@ -765,7 +765,15 @@ def test_astype_dt64_to_string(
             item = item.iloc[0]
         if using_infer_string:
             assert item is pd.NA
-        else:
+
+        # Check that Series/DataFrame.astype matches DatetimeArray.astype
+        expected = frame_or_series(dta.astype("str"))
+        tm.assert_equal(result, expected)
+
+        item = result.iloc[0]
+        if frame_or_series is DataFrame:
+            item = item.iloc[0]
+        if using_infer_string:
             assert item is np.nan
 
     def test_astype_td64_to_string(self, frame_or_series):

pandas/tests/frame/methods/test_combine_first.py

@@ -30,7 +30,7 @@ def test_combine_first_mixed(self):
         combined = f.combine_first(g)
         tm.assert_frame_equal(combined, exp)
 
-    def test_combine_first(self, float_frame, using_infer_string):
+    def test_combine_first(self, float_frame):
         # disjoint
         head, tail = float_frame[:5], float_frame[5:]
 

pandas/tests/frame/methods/test_dtypes.py

@@ -137,5 +137,5 @@ def test_frame_apply_np_array_return_type(self, using_infer_string):
         # GH 35517
         df = DataFrame([["foo"]])
         result = df.apply(lambda col: np.array("bar"))
-        expected = Series(np.array(["bar"]), dtype=object)
+        expected = Series(np.array("bar"))
         tm.assert_series_equal(result, expected)