Backport PR #35882: BUG: item_cache invalidation in get_numeric_data (#36188)

Co-authored-by: jbrockmendel <[email protected]>

Author: meeseeksmachine

doc/source/whatsnew/v1.1.2.rst

@@ -40,6 +40,7 @@ Bug fixes
 - Bug in :class:`Series` constructor incorrectly raising a ``TypeError`` when passed an ordered set (:issue:`36044`)
 - Bug in :meth:`Series.dt.isocalendar` and :meth:`DatetimeIndex.isocalendar` that returned incorrect year for certain dates (:issue:`36032`)
 - Bug in :class:`DataFrame` indexing returning an incorrect :class:`Series` in some cases when the series has been altered and a cache not invalidated (:issue:`33675`)
+- Bug in :meth:`DataFrame.corr` causing subsequent indexing lookups to be incorrect (:issue:`35882`)
 
 .. ---------------------------------------------------------------------------
 

pandas/core/internals/managers.py

@@ -732,7 +732,6 @@ def get_numeric_data(self, copy: bool = False) -> "BlockManager":
         copy : bool, default False
             Whether to copy the blocks
         """
-        self._consolidate_inplace()
         return self._combine([b for b in self.blocks if b.is_numeric], copy)
 
     def _combine(self, blocks: List[Block], copy: bool = True) -> "BlockManager":

pandas/tests/frame/methods/test_cov_corr.py

@@ -191,6 +191,23 @@ def test_corr_nullable_integer(self, nullable_column, other_column, method):
         expected = pd.DataFrame(np.ones((2, 2)), columns=["a", "b"], index=["a", "b"])
         tm.assert_frame_equal(result, expected)
 
+    def test_corr_item_cache(self):
+        # Check that corr does not lead to incorrect entries in item_cache
+
+        df = pd.DataFrame({"A": range(10)})
+        df["B"] = range(10)[::-1]
+
+        ser = df["A"]  # populate item_cache
+        assert len(df._mgr.blocks) == 2
+
+        _ = df.corr()
+
+        # Check that the corr didnt break link between ser and df
+        ser.values[0] = 99
+        assert df.loc[0, "A"] == 99
+        assert df["A"] is ser
+        assert df.values[0, 0] == 99
+
 
 class TestDataFrameCorrWith:
     def test_corrwith(self, datetime_frame):