TST: Add test for operations on DataFrame with Interval CategoricalIndex

Author: another-green

pandas/tests/frame/test_arithmetic.py

@@ -642,3 +642,18 @@ def test_arith_non_pandas_object(self):
         val3 = np.random.rand(*df.shape)
         added = pd.DataFrame(df.values + val3, index=df.index, columns=df.columns)
         tm.assert_frame_equal(df.add(val3), added)
+
+    def test_operations_with_interval_categories_index(self, all_arithmetic_operators):
+        # GH#27415
+        op = all_arithmetic_operators
+        ind = pd.CategoricalIndex(pd.interval_range(start=0.0, end=2.0))
+
+        df = pd.DataFrame([[1, 2]], columns=ind)
+        num = 100
+        try:
+            getattr(df, op)(num)
+        except TypeError:
+            pytest.fail(
+                "Unexpected TypeError for operations on DataFrame\
+                 with interval categories as index"
+            )

pandas/tests/indexing/test_categorical.py

@@ -758,23 +758,3 @@ def test_map_with_dict_or_series(self):
         output = cur_index.map(mapper)
         # Order of categories in output can be different
         tm.assert_index_equal(expected, output)
-
-    def test_operations_with_interval_categories_index(self):
-        ind = pd.CategoricalIndex(pd.interval_range(start=0.0, end=2.0))
-        df = pd.DataFrame([[1, 2]], columns=ind)
-        # __add__
-        result = df + 100
-        expected = pd.DataFrame([[101, 102]], columns=ind)
-        tm.assert_frame_equal(result, expected)
-        # __substract__
-        result = df - 100
-        expected = pd.DataFrame([[-99, -98]], columns=ind)
-        tm.assert_frame_equal(result, expected)
-        # __multiply__
-        result = df * 100
-        expected = pd.DataFrame([[100, 200]], columns=ind)
-        tm.assert_frame_equal(result, expected)
-        # __divide__
-        result = df / 100
-        expected = pd.DataFrame([[0.01, 0.02]], columns=ind)
-        tm.assert_frame_equal(result, expected)