use assert[Not]In where appropriate
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 8d41bf0..27ed92e 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -487,7 +487,7 @@
         expect_somewhere = ["1st=1", "2nd=2", "3rd=3"]
         result = urllib.urlencode(given)
         for expected in expect_somewhere:
-            self.assertTrue(expected in result,
+            self.assertIn(expected, result,
                          "testing %s: %s not found in %s" %
                          (test_type, expected, result))
         self.assertEqual(result.count('&'), 2,
@@ -534,8 +534,7 @@
         result = urllib.urlencode(given, True)
         for value in given["sequence"]:
             expect = "sequence=%s" % value
-            self.assertTrue(expect in result,
-                         "%s not found in %s" % (expect, result))
+            self.assertIn(expect, result)
         self.assertEqual(result.count('&'), 2,
                          "Expected 2 '&'s, got %s" % result.count('&'))