diff --git a/pandas/core/frame.py b/pandas/core/frame.py index 8fd0cd8c66e3c..1be72c60783ec 100644 --- a/pandas/core/frame.py +++ b/pandas/core/frame.py @@ -651,25 +651,36 @@ 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 diff --git a/pandas/core/generic.py b/pandas/core/generic.py index c9e6ffe1d7dc6..8d2fa91edc81c 100644 --- a/pandas/core/generic.py +++ b/pandas/core/generic.py @@ -288,6 +288,7 @@ def _init_mgr( mgr = mgr.astype(dtype=dtype) return mgr + @final @classmethod def _from_mgr(cls, mgr: Manager, axes: list[Index]) -> Self: """ diff --git a/pandas/core/series.py b/pandas/core/series.py index 08e56cb4925b3..9dad4191975fa 100644 --- a/pandas/core/series.py +++ b/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 diff --git a/pandas/tests/frame/test_subclass.py b/pandas/tests/frame/test_subclass.py index 316216e69a587..355953eac9d51 100644 --- a/pandas/tests/frame/test_subclass.py +++ b/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