diff --git a/doc/source/whatsnew/v2.2.1.rst b/doc/source/whatsnew/v2.2.1.rst index b342eef850459..eb6e50c1be160 100644 --- a/doc/source/whatsnew/v2.2.1.rst +++ b/doc/source/whatsnew/v2.2.1.rst @@ -21,6 +21,7 @@ Fixed regressions - Fixed regression in :meth:`.DataFrameGroupBy.idxmin`, :meth:`.DataFrameGroupBy.idxmax`, :meth:`.SeriesGroupBy.idxmin`, :meth:`.SeriesGroupBy.idxmax` ignoring the ``skipna`` argument (:issue:`57040`) - Fixed regression in :meth:`.DataFrameGroupBy.idxmin`, :meth:`.DataFrameGroupBy.idxmax`, :meth:`.SeriesGroupBy.idxmin`, :meth:`.SeriesGroupBy.idxmax` where values containing the minimum or maximum value for the dtype could produce incorrect results (:issue:`57040`) - Fixed regression in :meth:`CategoricalIndex.difference` raising ``KeyError`` when other contains null values other than NaN (:issue:`57318`) +- Fixed regression in :meth:`DataFrame.groupby` raising ``ValueError`` when grouping by a :class:`Series` in some cases (:issue:`57276`) - Fixed regression in :meth:`DataFrame.loc` raising ``IndexError`` for non-unique, masked dtype indexes where result has more than 10,000 rows (:issue:`57027`) - Fixed regression in :meth:`DataFrame.merge` raising ``ValueError`` for certain types of 3rd-party extension arrays (:issue:`57316`) - Fixed regression in :meth:`DataFrame.sort_index` not producing a stable sort for a index with duplicates (:issue:`57151`) diff --git a/pandas/core/internals/managers.py b/pandas/core/internals/managers.py index 3719bf1f77f85..220bb1133dfd5 100644 --- a/pandas/core/internals/managers.py +++ b/pandas/core/internals/managers.py @@ -12,7 +12,6 @@ cast, ) import warnings -import weakref import numpy as np @@ -282,8 +281,8 @@ def references_same_values(self, mgr: BaseBlockManager, blkno: int) -> bool: Checks if two blocks from two different block managers reference the same underlying values. """ - ref = weakref.ref(self.blocks[blkno]) - return ref in mgr.blocks[blkno].refs.referenced_blocks + blk = self.blocks[blkno] + return any(blk is ref() for ref in mgr.blocks[blkno].refs.referenced_blocks) def get_dtypes(self) -> npt.NDArray[np.object_]: dtypes = np.array([blk.dtype for blk in self.blocks], dtype=object) diff --git a/pandas/tests/copy_view/test_methods.py b/pandas/tests/copy_view/test_methods.py index 862aebdc70a9d..5d1eefccbb1e7 100644 --- a/pandas/tests/copy_view/test_methods.py +++ b/pandas/tests/copy_view/test_methods.py @@ -280,6 +280,17 @@ def test_reset_index_series_drop(using_copy_on_write, index): tm.assert_series_equal(ser, ser_orig) +def test_groupby_column_index_in_references(): + df = DataFrame( + {"A": ["a", "b", "c", "d"], "B": [1, 2, 3, 4], "C": ["a", "a", "b", "b"]} + ) + df = df.set_index("A") + key = df["C"] + result = df.groupby(key, observed=True).sum() + expected = df.groupby("C", observed=True).sum() + tm.assert_frame_equal(result, expected) + + def test_rename_columns(using_copy_on_write): # Case: renaming columns returns a new dataframe # + afterwards modifying the result