catch ValueErrors in now invalid test cases.

Author: groutr

pandas/tests/indexes/test_base.py

@@ -1412,9 +1412,11 @@ def test_str_attribute(self):
         tm.assert_index_equal(idx.str.split(), expected)
         tm.assert_index_equal(idx.str.split(expand=False), expected)
 
-        expected = MultiIndex.from_tuples([('a', 'b', 'c'), ('d', 'e', np.nan),
-                                           ('f', np.nan, np.nan)])
-        tm.assert_index_equal(idx.str.split(expand=True), expected)
+        # This is invalid behavior
+        with self.assertRaises(ValueError):
+            expected = MultiIndex.from_tuples([('a', 'b', 'c'), ('d', 'e', np.nan),
+                                            ('f', np.nan, np.nan)])
+            tm.assert_index_equal(idx.str.split(expand=True), expected)
 
         # test boolean case, should return np.array instead of boolean Index
         idx = Index(['a1', 'a2', 'b1', 'b2'])

pandas/tests/test_strings.py

@@ -1951,13 +1951,14 @@ def test_split_to_multiindex_expand(self):
         tm.assert_index_equal(result, exp)
         self.assertEqual(result.nlevels, 3)
 
-        idx = Index(['some_unequal_splits', 'one_of_these_things_is_not'])
-        result = idx.str.split('_', expand=True)
-        exp = MultiIndex.from_tuples([('some', 'unequal', 'splits', NA, NA, NA
-                                       ), ('one', 'of', 'these', 'things',
-                                           'is', 'not')])
-        tm.assert_index_equal(result, exp)
-        self.assertEqual(result.nlevels, 6)
+        with self.assertRaises(ValueError):
+            idx = Index(['some_unequal_splits', 'one_of_these_things_is_not'])
+            result = idx.str.split('_', expand=True)
+            exp = MultiIndex.from_tuples([('some', 'unequal', 'splits', NA, NA, NA
+                                        ), ('one', 'of', 'these', 'things',
+                                            'is', 'not')])
+            tm.assert_index_equal(result, exp)
+            self.assertEqual(result.nlevels, 6)
 
         with tm.assertRaisesRegexp(ValueError, "expand must be"):
             idx.str.split('_', expand="not_a_boolean")