BUG: Check for duplicate names columns and index in crosstab

pandas/core/reshape/pivot.py

@@ -496,6 +496,17 @@ def crosstab(index, columns, values=None, rownames=None, colnames=None,
     common_idx = _get_objs_combined_axis(index + columns, intersect=True,
                                          sort=False)
 
+    if len(set(rownames)) != len(rownames):
+        raise ValueError("Duplicated index/row names not allowed")
+    if len(set(colnames)) != len(colnames):
+        raise ValueError("Duplicated column names not allowed")
+
+    repeated_names = set(rownames).intersection(set(colnames))
+    if repeated_names:
+        raise ValueError("Column and rows cannot share the same names. "
+                         "Repeated names: {repeated_names}"
+                         .format(repeated_names=", ".join(repeated_names)))
+
     data = {}
     data.update(zip(rownames, index))
     data.update(zip(colnames, columns))

pandas/tests/reshape/test_pivot.py

@@ -1830,16 +1830,30 @@ def test_crosstab_with_numpy_size(self):
                                 columns=expected_column)
         tm.assert_frame_equal(result, expected)
 
+
     def test_crosstab_dup_index_names(self):
-        # GH 13279
-        s = pd.Series(range(3), name='foo')
+        s1 = pd.Series(range(3), name='foo')
+        s2 = s1 + 1
+
+        msg = "Column and rows cannot share the same names. " \
+              "Repeated names: foo"
+        with pytest.raises(ValueError, match=msg):
+            pd.crosstab(s1, s2)
+        with pytest.raises(ValueError, match=msg):
+            pd.crosstab(s1, [s2, s2.rename("bar")])
+
+        msg = "Duplicated column names not allowed"
+        with pytest.raises(ValueError, match=msg):
+            pd.crosstab(s1.rename("bar"), [s2, s2])
+        with pytest.raises(ValueError, match=msg):
+            pd.crosstab(s1.rename("bar"), [s2.rename("one"), s2, s2])
+
+        msg = "Duplicated index/row names not allowed"
+        with pytest.raises(ValueError, match=msg):
+            pd.crosstab([s1, s1], s2.rename("bar"))
+        with pytest.raises(ValueError, match=msg):
+            pd.crosstab([s1, s1, s1.rename("one")], s2.rename("bar"))
 
-        result = pd.crosstab(s, s)
-        expected_index = pd.Index(range(3), name='foo')
-        expected = pd.DataFrame(np.eye(3, dtype=np.int64),
-                                index=expected_index,
-                                columns=expected_index)
-        tm.assert_frame_equal(result, expected)
 
     @pytest.mark.parametrize("names", [['a', ('b', 'c')],
                                        [('a', 'b'), 'c']])