add whatsnew entry, update comment and unit tests in test_crosstab.py

Author: CloseChoice

doc/source/whatsnew/v1.1.0.rst

@@ -1125,6 +1125,7 @@ Reshaping
 - Bug in :meth:`Series.where` with an empty Series and empty ``cond`` having non-bool dtype (:issue:`34592`)
 - Fixed regression where :meth:`DataFrame.apply` would raise ``ValueError`` for elements whth ``S`` dtype (:issue:`34529`)
 - Bug in :meth:`DataFrame.append` leading to sorting columns even when ``sort=False`` is specified (:issue:`35092`)
+- Bug in func :meth:`crosstab` when using multiple columns with ``margins=True`` and ``normalize=True`` (:issue:`35144`)
 
 Sparse
 ^^^^^^

pandas/core/reshape/pivot.py

@@ -671,7 +671,7 @@ def _normalize(table, normalize, margins: bool, margins_name="All"):
         table_index = table.index
         table_columns = table.columns
 
-        # check if margin name is in (for MI cases) or equal to last
+        # check if margin name is not in (for MI cases) and not equal to last
         # index/column and save the column and index margin
         if (margins_name not in table.iloc[-1, :].name) & (
             margins_name != table.iloc[:, -1].name

pandas/tests/reshape/test_crosstab.py

@@ -699,26 +699,8 @@ def test_margin_normalize(self):
         )
         tm.assert_frame_equal(result, expected)
 
-    def test_crosstab_multiple_columns_normalize(self):
-        df = DataFrame(
-            {
-                "A": ["foo", "foo", "foo", "foo", "foo", "bar", "bar", "bar", "bar"],
-                "B": ["one", "one", "one", "two", "two", "one", "one", "two", "two"],
-                "C": [
-                    "small",
-                    "large",
-                    "large",
-                    "small",
-                    "small",
-                    "large",
-                    "small",
-                    "small",
-                    "large",
-                ],
-                "D": [1, 2, 2, 3, 3, 4, 5, 6, 7],
-                "E": [2, 4, 5, 5, 6, 6, 8, 9, 9],
-            }
-        )
+        # GH 35144
+        # use multiple columns with margins and normalization
         result = crosstab(
             index=df.C,
             columns=[df.A, df.B],