use assert[Not]In where appropriate
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index e28c4b0..4f2a0b7 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -388,8 +388,7 @@
         self.assertTrue(isinstance(vi.major, int))
         self.assertTrue(isinstance(vi.minor, int))
         self.assertTrue(isinstance(vi.micro, int))
-        self.assertTrue(vi.releaselevel in
-                     ("alpha", "beta", "candidate", "final"))
+        self.assertIn(vi.releaselevel, ("alpha", "beta", "candidate", "final"))
         self.assertTrue(isinstance(vi.serial, int))
         self.assertEqual(vi[0], vi.major)
         self.assertEqual(vi[1], vi.minor)