Used @pytest.mark.parametrize in tests, added whatsnew

Author: anzor

doc/source/whatsnew/v3.0.0.rst

@@ -665,7 +665,7 @@ Indexing
 ^^^^^^^^
 - Bug in :meth:`DataFrame.__getitem__` returning modified columns when called with ``slice`` in Python 3.12 (:issue:`57500`)
 - Bug in :meth:`DataFrame.from_records` throwing a ``ValueError`` when passed an empty list in ``index`` (:issue:`58594`)
--
+- Fixed bug in :meth:`DataFrame.loc` with inconsistent behavior of loc-set with 2 given indexes to Series (:issue:`599333`)
 
 Missing
 ^^^^^^^

pandas/tests/indexing/test_loc.py

@@ -3298,42 +3298,55 @@ def test_loc_reindexing_of_empty_index(self):
         expected = DataFrame(index=[1, 1, 2, 2], data=["1", "1", "2", "2"])
         tm.assert_frame_equal(df, expected)
 
-    def test_loc_set_series_to_multiple_columns(self):
+    @pytest.mark.parametrize(
+        "df, row_index, col_index, setting_series, expected_df",
+        [
+            [
+                DataFrame([[1, 2, 3], [4, 5, 6]], columns=list("ABC")),
+                slice(0, 3),
+                ["A", "B", "C"],
+                Series([10, 20, 30]),
+                DataFrame([[10, 10, 10], [20, 20, 20]], columns=list("ABC")),
+            ],
+            [
+                DataFrame([[1, 2, 3], [4, 5, 6]], columns=list("ABC")),
+                slice(None),
+                ["A", "B", "C"],
+                Series([10, 20, 30]),
+                DataFrame([[10, 10, 10], [20, 20, 20]], columns=list("ABC")),
+            ],
+            [
+                DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]], columns=list("ABC")),
+                [True, True, True],
+                ["A", "B", "C"],
+                Series([10, 20, 30]),
+                DataFrame(
+                    [[10, 10, 10], [20, 20, 20], [30, 30, 30]], columns=list("ABC")
+                ),
+            ],
+            [
+                DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]], columns=list("ABC")),
+                slice(0, 4),
+                ["A", "B", "C"],
+                Series([10, 20, 30]),
+                DataFrame(
+                    [[10, 10, 10], [20, 20, 20], [30, 30, 30]], columns=list("ABC")
+                ),
+            ],
+            [
+                DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]], columns=list("ABC")),
+                slice(None),
+                slice("A", "C"),
+                Series([10, 20, 30]),
+                DataFrame(
+                    [[10, 10, 10], [20, 20, 20], [30, 30, 30]], columns=list("ABC")
+                ),
+            ],
+        ],
+    )
+    def test_loc_set_series_to_multiple_columns(
+        self, df, row_index, col_index, setting_series, expected_df
+    ):
         # GH 59933
-        df = DataFrame([[1, 2, 3], [4, 5, 6]], columns=list("ABC"))
-        df.loc[0:3, ["A", "B", "C"]] = Series([10, 20, 30])
-        expected = DataFrame([[10, 10, 10], [20, 20, 20]], columns=list("ABC"))
-        tm.assert_frame_equal(df, expected)
-
-        df = DataFrame([[1, 2, 3], [4, 5, 6]], columns=list("ABC"))
-        df.loc[:, ["A", "B", "C"]] = Series([10, 20, 30])
-        expected = DataFrame([[10, 10, 10], [20, 20, 20]], columns=list("ABC"))
-        tm.assert_frame_equal(df, expected)
-
-        df = DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]], columns=list("ABC"))
-        df.loc[df["A"] > 0, ["A", "B", "C"]] = Series([10, 20, 30])
-        expected = DataFrame(
-            [[10, 10, 10], [20, 20, 20], [30, 30, 30]], columns=list("ABC")
-        )
-        tm.assert_frame_equal(df, expected)
-
-        df = DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]], columns=list("ABC"))
-        df.loc[:, ["A", "B", "C"]] = Series([10, 20, 30])
-        expected = DataFrame(
-            [[10, 10, 10], [20, 20, 20], [30, 30, 30]], columns=list("ABC")
-        )
-        tm.assert_frame_equal(df, expected)
-
-        df = DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]], columns=list("ABC"))
-        df.loc[0:4, ["A", "B", "C"]] = Series([10, 20, 30])
-        expected = DataFrame(
-            [[10, 10, 10], [20, 20, 20], [30, 30, 30]], columns=list("ABC")
-        )
-        tm.assert_frame_equal(df, expected)
-
-        df = DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]], columns=list("ABC"))
-        df.loc[:, "A":"C"] = Series([10, 20, 30])
-        expected = DataFrame(
-            [[10, 10, 10], [20, 20, 20], [30, 30, 30]], columns=list("ABC")
-        )
-        tm.assert_frame_equal(df, expected)
+        df.loc[row_index, col_index] = setting_series
+        tm.assert_frame_equal(df, expected_df)