TST Add test for iloc on interval index (pandas-dev#40866)

Author: EricLeer

pandas/tests/indexing/test_iloc.py

@@ -17,6 +17,7 @@
     CategoricalDtype,
     DataFrame,
     Index,
+    Interval,
     NaT,
     Series,
     array,
@@ -1092,6 +1093,23 @@ def test_iloc_getitem_with_duplicates2(self):
         expected = df.take([0], axis=1)
         tm.assert_frame_equal(result, expected)
 
+    def test_iloc_interval(self):
+        # GH#17130
+        df = DataFrame({Interval(1, 2): [1, 2]})
+
+        result = df.iloc[0]
+        expected = Series({Interval(1, 2): 1}, name=0)
+        tm.assert_series_equal(result, expected)
+
+        result = df.iloc[:, 0]
+        expected = Series([1, 2], name=Interval(1, 2))
+        tm.assert_series_equal(result, expected)
+
+        result = df.copy()
+        result.iloc[:, 0] += 1
+        expected = DataFrame({Interval(1, 2): [2, 3]})
+        tm.assert_frame_equal(result, expected)
+
 
 class TestILocErrors:
     # NB: this test should work for _any_ Series we can pass as