use skipUnless

Lib/test/test_readline.py

@@ -15,7 +15,7 @@ class TestHistoryManipulation (unittest.TestCase):
     That's why the tests cover only a small subset of the interface.
     """
 
-    @unittest.skipIf(not hasattr(readline, 'clear_history'),
+    @unittest.skipUnless(hasattr(readline, "clear_history"),
                          "The history update test cannot be run because the "
                          "clear_history method is not available.")
     def testHistoryUpdates(self):