API: avoid passing Manager to subclass __init__ (#57553)

Author: jbrockmendel

pandas/core/frame.py

@@ -653,25 +653,36 @@ def _constructor(self) -> type[DataFrame]:
         return DataFrame
 
     def _constructor_from_mgr(self, mgr, axes) -> DataFrame:
-        if self._constructor is DataFrame:
-            # we are pandas.DataFrame (or a subclass that doesn't override _constructor)
-            return DataFrame._from_mgr(mgr, axes=axes)
-        else:
-            assert axes is mgr.axes
+        df = DataFrame._from_mgr(mgr, axes=axes)
+
+        if type(self) is DataFrame:
+            # This would also work `if self._constructor is DataFrame`, but
+            #  this check is slightly faster, benefiting the most-common case.
+            return df
+
+        elif type(self).__name__ == "GeoDataFrame":
+            # Shim until geopandas can override their _constructor_from_mgr
+            #  bc they have different behavior for Managers than for DataFrames
             return self._constructor(mgr)
 
-    _constructor_sliced: Callable[..., Series] = Series
+        # We assume that the subclass __init__ knows how to handle a
+        #  pd.DataFrame object.
+        return self._constructor(df)
 
-    def _sliced_from_mgr(self, mgr, axes) -> Series:
-        return Series._from_mgr(mgr, axes)
+    _constructor_sliced: Callable[..., Series] = Series
 
     def _constructor_sliced_from_mgr(self, mgr, axes) -> Series:
-        if self._constructor_sliced is Series:
-            ser = self._sliced_from_mgr(mgr, axes)
-            ser._name = None  # caller is responsible for setting real name
+        ser = Series._from_mgr(mgr, axes)
+        ser._name = None  # caller is responsible for setting real name
+
+        if type(self) is DataFrame:
+            # This would also work `if self._constructor_sliced is Series`, but
+            #  this check is slightly faster, benefiting the most-common case.
             return ser
-        assert axes is mgr.axes
-        return self._constructor_sliced(mgr)
+
+        # We assume that the subclass __init__ knows how to handle a
+        #  pd.Series object.
+        return self._constructor_sliced(ser)
 
     # ----------------------------------------------------------------------
     # Constructors

pandas/core/generic.py

@@ -287,6 +287,7 @@ def _init_mgr(
                 mgr = mgr.astype(dtype=dtype)
         return mgr
 
+    @final
     @classmethod
     def _from_mgr(cls, mgr: Manager, axes: list[Index]) -> Self:
         """

pandas/core/series.py

@@ -576,14 +576,17 @@ def _constructor(self) -> type[Series]:
         return Series
 
     def _constructor_from_mgr(self, mgr, axes):
-        if self._constructor is Series:
-            # we are pandas.Series (or a subclass that doesn't override _constructor)
-            ser = Series._from_mgr(mgr, axes=axes)
-            ser._name = None  # caller is responsible for setting real name
+        ser = Series._from_mgr(mgr, axes=axes)
+        ser._name = None  # caller is responsible for setting real name
+
+        if type(self) is Series:
+            # This would also work `if self._constructor is Series`, but
+            #  this check is slightly faster, benefiting the most-common case.
             return ser
-        else:
-            assert axes is mgr.axes
-            return self._constructor(mgr)
+
+        # We assume that the subclass __init__ knows how to handle a
+        #  pd.Series object.
+        return self._constructor(ser)
 
     @property
     def _constructor_expanddim(self) -> Callable[..., DataFrame]:
@@ -595,18 +598,19 @@ def _constructor_expanddim(self) -> Callable[..., DataFrame]:
 
         return DataFrame
 
-    def _expanddim_from_mgr(self, mgr, axes) -> DataFrame:
+    def _constructor_expanddim_from_mgr(self, mgr, axes):
         from pandas.core.frame import DataFrame
 
-        return DataFrame._from_mgr(mgr, axes=mgr.axes)
+        df = DataFrame._from_mgr(mgr, axes=mgr.axes)
 
-    def _constructor_expanddim_from_mgr(self, mgr, axes):
-        from pandas.core.frame import DataFrame
+        if type(self) is Series:
+            # This would also work `if self._constructor_expanddim is DataFrame`,
+            #  but this check is slightly faster, benefiting the most-common case.
+            return df
 
-        if self._constructor_expanddim is DataFrame:
-            return self._expanddim_from_mgr(mgr, axes)
-        assert axes is mgr.axes
-        return self._constructor_expanddim(mgr)
+        # We assume that the subclass __init__ knows how to handle a
+        #  pd.DataFrame object.
+        return self._constructor_expanddim(df)
 
     # types
     @property

pandas/tests/frame/test_subclass.py

@@ -16,6 +16,17 @@
 
 
 class TestDataFrameSubclassing:
+    def test_no_warning_on_mgr(self):
+        # GH#57032
+        df = tm.SubclassedDataFrame(
+            {"X": [1, 2, 3], "Y": [1, 2, 3]}, index=["a", "b", "c"]
+        )
+        with tm.assert_produces_warning(None):
+            # df.isna() goes through _constructor_from_mgr, which we want to
+            #  *not* pass a Manager do __init__
+            df.isna()
+            df["X"].isna()
+
     def test_frame_subclassing_and_slicing(self):
         # Subclass frame and ensure it returns the right class on slicing it
         # In reference to PR 9632