BUG: TypeError when shifting DataFrame created by concatenation of slices and fills with values (pandas-dev#42453)

Author: wjsi

doc/source/whatsnew/v1.3.2.rst

@@ -17,6 +17,7 @@ Fixed regressions
 - Performance regression in :meth:`DataFrame.isin` and :meth:`Series.isin` for nullable data types (:issue:`42714`)
 - Regression in updating values of :class:`pandas.Series` using boolean index, created by using :meth:`pandas.DataFrame.pop` (:issue:`42530`)
 - Regression in :meth:`DataFrame.from_records` with empty records (:issue:`42456`)
+- Fixed regression in :meth:`DataFrame.shift` where TypeError occurred when shifting DataFrame created by concatenation of slices and fills with values (:issue:`42719`)
 -
 
 .. ---------------------------------------------------------------------------

pandas/core/internals/managers.py

@@ -386,10 +386,14 @@ def shift(self: T, periods: int, axis: int, fill_value) -> T:
             # We only get here with fill_value not-lib.no_default
             ncols = self.shape[0]
             if periods > 0:
-                indexer = [-1] * periods + list(range(ncols - periods))
+                indexer = np.array(
+                    [-1] * periods + list(range(ncols - periods)), dtype=np.intp
+                )
             else:
                 nper = abs(periods)
-                indexer = list(range(nper, ncols)) + [-1] * nper
+                indexer = np.array(
+                    list(range(nper, ncols)) + [-1] * nper, dtype=np.intp
+                )
             result = self.reindex_indexer(
                 self.items,
                 indexer,

pandas/tests/frame/methods/test_shift.py

@@ -183,6 +183,32 @@ def test_shift_axis1_multiple_blocks(self, using_array_manager):
 
         tm.assert_frame_equal(result, expected)
 
+    @td.skip_array_manager_not_yet_implemented  # TODO(ArrayManager) axis=1 support
+    def test_shift_axis1_multiple_blocks_with_int_fill(self):
+        # GH#42719
+        df1 = DataFrame(np.random.randint(1000, size=(5, 3)))
+        df2 = DataFrame(np.random.randint(1000, size=(5, 2)))
+        df3 = pd.concat([df1.iloc[:4, 1:3], df2.iloc[:4, :]], axis=1)
+        result = df3.shift(2, axis=1, fill_value=np.int_(0))
+        assert len(df3._mgr.blocks) == 2
+
+        expected = df3.take([-1, -1, 0, 1], axis=1)
+        expected.iloc[:, :2] = np.int_(0)
+        expected.columns = df3.columns
+
+        tm.assert_frame_equal(result, expected)
+
+        # Case with periods < 0
+        df3 = pd.concat([df1.iloc[:4, 1:3], df2.iloc[:4, :]], axis=1)
+        result = df3.shift(-2, axis=1, fill_value=np.int_(0))
+        assert len(df3._mgr.blocks) == 2
+
+        expected = df3.take([2, 3, -1, -1], axis=1)
+        expected.iloc[:, -2:] = np.int_(0)
+        expected.columns = df3.columns
+
+        tm.assert_frame_equal(result, expected)
+
     @pytest.mark.filterwarnings("ignore:tshift is deprecated:FutureWarning")
     def test_tshift(self, datetime_frame):
         # TODO: remove this test when tshift deprecation is enforced