wip enforce pdep6

Author: MarcoGorelli

pandas/tests/copy_view/test_indexing.py

@@ -725,16 +725,15 @@ def test_column_as_series_set_with_upcast(backend):
         with pytest.raises(TypeError, match="Invalid value"):
             s[0] = "foo"
         expected = Series([1, 2, 3], name="a")
+        tm.assert_series_equal(s, expected)
+        tm.assert_frame_equal(df, df_orig)
+        # ensure cached series on getitem is not the changed series
+        tm.assert_series_equal(df["a"], df_orig["a"])
     else:
         with pytest.raises(TypeError, match="Invalid value"):
             s[0] = "foo"
             return
 
-    tm.assert_series_equal(s, expected)
-    tm.assert_frame_equal(df, df_orig)
-    # ensure cached series on getitem is not the changed series
-    tm.assert_series_equal(df["a"], df_orig["a"])
-
 
 @pytest.mark.parametrize(
     "method",

pandas/tests/indexing/multiindex/test_setitem.py

@@ -215,6 +215,8 @@ def test_multiindex_assignment_single_dtype(self):
         # arr + 0.5 cannot be cast losslessly to int, so we upcast
         with pytest.raises(TypeError, match="Invalid value"):
             df.loc[4, "c"] = arr + 0.5
+        df = df.astype({"c": "float64"})
+        df.loc[4, "c"] = arr + 0.5
 
         # scalar ok
         df.loc[4, "c"] = 10