Fixed metadata propagation in Dataframe.combine and Dataframe.combine_first

Author: jinlixiao

pandas/core/frame.py

@@ -8285,7 +8285,8 @@ def combine(
             result[col] = arr
 
         # convert_objects just in case
-        return self._constructor(result, index=new_index, columns=new_columns)
+        result = self._constructor(result, index=new_index, columns=new_columns)
+        return result.__finalize__(self, method="combine")
 
     def combine_first(self, other: DataFrame) -> DataFrame:
         """
@@ -8360,7 +8361,7 @@ def combiner(x, y):
         if dtypes:
             combined = combined.astype(dtypes)
 
-        return combined
+        return combined.__finalize__(self, method="combine_first")
 
     def update(
         self,

pandas/tests/generic/test_finalize.py

@@ -115,21 +115,15 @@
         operator.methodcaller("add", pd.DataFrame(*frame_data)),
     ),
     # TODO: div, mul, etc.
-    pytest.param(
-        (
-            pd.DataFrame,
-            frame_data,
-            operator.methodcaller("combine", pd.DataFrame(*frame_data), operator.add),
-        ),
-        marks=not_implemented_mark,
+    (
+        pd.DataFrame,
+        frame_data,
+        operator.methodcaller("combine", pd.DataFrame(*frame_data), operator.add),
     ),
-    pytest.param(
-        (
-            pd.DataFrame,
-            frame_data,
-            operator.methodcaller("combine_first", pd.DataFrame(*frame_data)),
-        ),
-        marks=not_implemented_mark,
+    (
+        pd.DataFrame,
+        frame_data,
+        operator.methodcaller("combine_first", pd.DataFrame(*frame_data)),
     ),
     pytest.param(
         (