diff --git a/Lib/test/mapping_tests.py b/Lib/test/mapping_tests.py
index ea6a717..f446b39 100644
--- a/Lib/test/mapping_tests.py
+++ b/Lib/test/mapping_tests.py
@@ -56,9 +56,9 @@
         self.assertEqual(len(d), len(self.reference))
         #__contains__
         for k in self.reference:
-            self.assertTrue(k in d)
+            self.assertIn(k, d)
         for k in self.other:
-            self.assertFalse(k in d)
+            self.assertNotIn(k, d)
         #cmp
         self.assertEqual(p, p)
         self.assertEqual(d, d)
@@ -85,7 +85,7 @@
         knownkey, knownvalue = next(iter(self.other.items()))
         self.assertEqual(d.get(key, knownvalue), value)
         self.assertEqual(d.get(knownkey, knownvalue), knownvalue)
-        self.assertFalse(knownkey in d)
+        self.assertNotIn(knownkey, d)
 
     def test_write(self):
         # Test for write operations on mapping
@@ -115,16 +115,16 @@
         self.assertEqual(d[knownkey], knownvalue)
         #pop
         self.assertEqual(d.pop(knownkey), knownvalue)
-        self.assertFalse(knownkey in d)
+        self.assertNotIn(knownkey, d)
         self.assertRaises(KeyError, d.pop, knownkey)
         default = 909
         d[knownkey] = knownvalue
         self.assertEqual(d.pop(knownkey, default), knownvalue)
-        self.assertFalse(knownkey in d)
+        self.assertNotIn(knownkey, d)
         self.assertEqual(d.pop(knownkey, default), default)
         #popitem
         key, value = d.popitem()
-        self.assertFalse(key in d)
+        self.assertNotIn(key, d)
         self.assertEqual(value, self.reference[key])
         p=self._empty_mapping()
         self.assertRaises(KeyError, p.popitem)
@@ -142,8 +142,8 @@
         d = self._empty_mapping()
         self.assertEqual(list(d.keys()), [])
         d = self.reference
-        self.assertTrue(list(self.inmapping.keys())[0] in d.keys())
-        self.assertTrue(list(self.other.keys())[0] not in d.keys())
+        self.assertIn(list(self.inmapping.keys())[0], d.keys())
+        self.assertNotIn(list(self.other.keys())[0], d.keys())
         self.assertRaises(TypeError, d.keys, None)
 
     def test_values(self):
@@ -320,9 +320,9 @@
         self.assertEqual(list(d.keys()), [])
         d = self._full_mapping({'a': 1, 'b': 2})
         k = d.keys()
-        self.assertTrue('a' in k)
-        self.assertTrue('b' in k)
-        self.assertTrue('c' not in k)
+        self.assertIn('a', k)
+        self.assertIn('b', k)
+        self.assertNotIn('c', k)
 
     def test_values(self):
         BasicTestMappingProtocol.test_values(self)
@@ -337,12 +337,13 @@
 
     def test_contains(self):
         d = self._empty_mapping()
+        self.assertNotIn('a', d)
         self.assertTrue(not ('a' in d))
         self.assertTrue('a' not in d)
         d = self._full_mapping({'a': 1, 'b': 2})
-        self.assertTrue('a' in d)
-        self.assertTrue('b' in d)
-        self.assertTrue('c' not in d)
+        self.assertIn('a', d)
+        self.assertIn('b', d)
+        self.assertNotIn('c', d)
 
         self.assertRaises(TypeError, d.__contains__)
 
diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index 7ded8b6..dc1d156 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -770,8 +770,8 @@
 
             # Dump using protocol 1 for comparison.
             s1 = self.dumps(x, 1)
-            self.assertTrue(__name__.encode("utf-8") in s1)
-            self.assertTrue(b"MyList" in s1)
+            self.assertIn(__name__.encode("utf-8"), s1)
+            self.assertIn(b"MyList", s1)
             self.assertEqual(opcode_in_pickle(opcode, s1), False)
 
             y = self.loads(s1)
@@ -780,8 +780,8 @@
 
             # Dump using protocol 2 for test.
             s2 = self.dumps(x, 2)
-            self.assertTrue(__name__.encode("utf-8") not in s2)
-            self.assertTrue(b"MyList" not in s2)
+            self.assertNotIn(__name__.encode("utf-8"), s2)
+            self.assertNotIn(b"MyList", s2)
             self.assertEqual(opcode_in_pickle(opcode, s2), True, repr(s2))
 
             y = self.loads(s2)
diff --git a/Lib/test/seq_tests.py b/Lib/test/seq_tests.py
index 5148d4b..d181e19 100644
--- a/Lib/test/seq_tests.py
+++ b/Lib/test/seq_tests.py
@@ -199,9 +199,9 @@
     def test_contains(self):
         u = self.type2test([0, 1, 2])
         for i in u:
-            self.assert_(i in u)
+            self.assertIn(i, u)
         for i in min(u)-1, max(u)+1:
-            self.assert_(i not in u)
+            self.assertNotIn(i, u)
 
         self.assertRaises(TypeError, u.__contains__)
 
@@ -213,8 +213,8 @@
             def __eq__(self, other):
                 return True
             __hash__ = None # Can't meet hash invariant requirements
-        self.assert_(AllEq() not in self.type2test([]))
-        self.assert_(AllEq() in self.type2test([1]))
+        self.assertNotIn(AllEq(), self.type2test([]))
+        self.assertIn(AllEq(), self.type2test([1]))
 
     def test_contains_order(self):
         # Sequences must test in-order.  If a rich comparison has side
@@ -227,7 +227,7 @@
                 raise DoNotTestEq
 
         checkfirst = self.type2test([1, StopCompares()])
-        self.assert_(1 in checkfirst)
+        self.assertIn(1, checkfirst)
         checklast = self.type2test([StopCompares(), 1])
         self.assertRaises(DoNotTestEq, checklast.__contains__, 1)
 
diff --git a/Lib/test/test_bigmem.py b/Lib/test/test_bigmem.py
index 843abb9..6b54e85 100644
--- a/Lib/test/test_bigmem.py
+++ b/Lib/test/test_bigmem.py
@@ -520,9 +520,9 @@
         s = _('').join([edge, SUBSTR, edge])
         del edge
         self.assertIn(SUBSTR, s)
-        self.assertFalse(SUBSTR * 2 in s)
+        self.assertNotIn(SUBSTR * 2, s)
         self.assertIn(_('-'), s)
-        self.assertFalse(_('a') in s)
+        self.assertNotIn(_('a'), s)
         s += _('a')
         self.assertIn(_('a'), s)
 
@@ -769,8 +769,8 @@
         t = (1, 2, 3, 4, 5) * size
         self.assertEquals(len(t), size * 5)
         self.assertIn(5, t)
-        self.assertFalse((1, 2, 3, 4, 5) in t)
-        self.assertFalse(0 in t)
+        self.assertNotIn((1, 2, 3, 4, 5), t)
+        self.assertNotIn(0, t)
 
     @bigmemtest(minsize=_2G + 10, memuse=8)
     def test_hash(self, size):
@@ -918,8 +918,8 @@
         l = [1, 2, 3, 4, 5] * size
         self.assertEquals(len(l), size * 5)
         self.assertIn(5, l)
-        self.assertFalse([1, 2, 3, 4, 5] in l)
-        self.assertFalse(0 in l)
+        self.assertNotIn([1, 2, 3, 4, 5], l)
+        self.assertNotIn(0, l)
 
     @bigmemtest(minsize=_2G + 10, memuse=8)
     def test_hash(self, size):
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index f05bd96..f456226 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -231,8 +231,7 @@
         b = self.type2test(b"abc")
         self.assertIn(ord('a'), b)
         self.assertIn(int(ord('a')), b)
-        self.assertFalse(200 in b)
-        self.assertFalse(200 in b)
+        self.assertNotIn(200, b)
         self.assertRaises(ValueError, lambda: 300 in b)
         self.assertRaises(ValueError, lambda: -1 in b)
         self.assertRaises(TypeError, lambda: None in b)
@@ -246,10 +245,10 @@
             self.assertIn(f(b"ab"), b)
             self.assertIn(f(b"bc"), b)
             self.assertIn(f(b"abc"), b)
-            self.assertFalse(f(b"ac") in b)
-            self.assertFalse(f(b"d") in b)
-            self.assertFalse(f(b"dab") in b)
-            self.assertFalse(f(b"abd") in b)
+            self.assertNotIn(f(b"ac"), b)
+            self.assertNotIn(f(b"d"), b)
+            self.assertNotIn(f(b"dab"), b)
+            self.assertNotIn(f(b"abd"), b)
 
     def test_fromhex(self):
         self.assertRaises(TypeError, self.type2test.fromhex)
diff --git a/Lib/test/test_cfgparser.py b/Lib/test/test_cfgparser.py
index a3d2640..6271d6f 100644
--- a/Lib/test/test_cfgparser.py
+++ b/Lib/test/test_cfgparser.py
@@ -76,8 +76,8 @@
         eq(cf.get('Spaces', 'key with spaces'), 'value')
         eq(cf.get('Spaces', 'another with spaces'), 'splat!')
 
-        self.assertFalse('__name__' in cf.options("Foo Bar"),
-                    '__name__ "option" should not be exposed by the API!')
+        self.assertNotIn('__name__', cf.options("Foo Bar"),
+                         '__name__ "option" should not be exposed by the API!')
 
         # Make sure the right things happen for remove_option();
         # added to include check for SourceForge bug #123324:
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index 1c3d4fe..cadac99 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -540,10 +540,10 @@
         self.assertEqual(c, dict(a=4, b=0, d=-2, e=-5, f=4))
         self.assertEqual(''.join(sorted(c.elements())), 'aaaaffff')
         self.assertEqual(c.pop('f'), 4)
-        self.assertEqual('f' in c, False)
+        self.assertNotIn('f', c)
         for i in range(3):
             elem, cnt = c.popitem()
-            self.assertEqual(elem in c, False)
+            self.assertNotIn(elem, c)
         c.clear()
         self.assertEqual(c, {})
         self.assertEqual(repr(c), 'Counter()')
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
index af4572f..cd74052 100644
--- a/Lib/test/test_compile.py
+++ b/Lib/test/test_compile.py
@@ -317,56 +317,56 @@
         d[1] += 1
         self.assertEqual(d[1], 2)
         del d[1]
-        self.assertEqual(1 in d, False)
+        self.assertNotIn(1, d)
         # Tuple of indices
         d[1, 1] = 1
         self.assertEqual(d[1, 1], 1)
         d[1, 1] += 1
         self.assertEqual(d[1, 1], 2)
         del d[1, 1]
-        self.assertEqual((1, 1) in d, False)
+        self.assertNotIn((1, 1), d)
         # Simple slice
         d[1:2] = 1
         self.assertEqual(d[1:2], 1)
         d[1:2] += 1
         self.assertEqual(d[1:2], 2)
         del d[1:2]
-        self.assertEqual(slice(1, 2) in d, False)
+        self.assertNotIn(slice(1, 2), d)
         # Tuple of simple slices
         d[1:2, 1:2] = 1
         self.assertEqual(d[1:2, 1:2], 1)
         d[1:2, 1:2] += 1
         self.assertEqual(d[1:2, 1:2], 2)
         del d[1:2, 1:2]
-        self.assertEqual((slice(1, 2), slice(1, 2)) in d, False)
+        self.assertNotIn((slice(1, 2), slice(1, 2)), d)
         # Extended slice
         d[1:2:3] = 1
         self.assertEqual(d[1:2:3], 1)
         d[1:2:3] += 1
         self.assertEqual(d[1:2:3], 2)
         del d[1:2:3]
-        self.assertEqual(slice(1, 2, 3) in d, False)
+        self.assertNotIn(slice(1, 2, 3), d)
         # Tuple of extended slices
         d[1:2:3, 1:2:3] = 1
         self.assertEqual(d[1:2:3, 1:2:3], 1)
         d[1:2:3, 1:2:3] += 1
         self.assertEqual(d[1:2:3, 1:2:3], 2)
         del d[1:2:3, 1:2:3]
-        self.assertEqual((slice(1, 2, 3), slice(1, 2, 3)) in d, False)
+        self.assertNotIn((slice(1, 2, 3), slice(1, 2, 3)), d)
         # Ellipsis
         d[...] = 1
         self.assertEqual(d[...], 1)
         d[...] += 1
         self.assertEqual(d[...], 2)
         del d[...]
-        self.assertEqual(Ellipsis in d, False)
+        self.assertNotIn(Ellipsis, d)
         # Tuple of Ellipses
         d[..., ...] = 1
         self.assertEqual(d[..., ...], 1)
         d[..., ...] += 1
         self.assertEqual(d[..., ...], 2)
         del d[..., ...]
-        self.assertEqual((Ellipsis, Ellipsis) in d, False)
+        self.assertNotIn((Ellipsis, Ellipsis), d)
 
     def test_annotation_limit(self):
         # 16 bits are available for # of annotations, but only 8 bits are
diff --git a/Lib/test/test_copy.py b/Lib/test/test_copy.py
index 2df0deb..732b4f4 100644
--- a/Lib/test/test_copy.py
+++ b/Lib/test/test_copy.py
@@ -627,7 +627,7 @@
         x, y = C(), C()
         # The underlying containers are decoupled
         v[x] = y
-        self.assertFalse(x in u)
+        self.assertNotIn(x, u)
 
     def test_copy_weakkeydict(self):
         self._check_copy_weakdict(weakref.WeakKeyDictionary)
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index 01a031a..658b390 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -140,10 +140,7 @@
         self.assertTrue(() != me)
 
         self.assertIn(me, [1, 20, [], me])
-        self.assertFalse(me not in [1, 20, [], me])
-
         self.assertIn([], [me, 1, 20, []])
-        self.assertFalse([] not in [me, 1, 20, []])
 
     def test_harmful_mixed_comparison(self):
         me = self.theclass(1, 1, 1)
diff --git a/Lib/test/test_dbm.py b/Lib/test/test_dbm.py
index 2008776..78357a0 100644
--- a/Lib/test/test_dbm.py
+++ b/Lib/test/test_dbm.py
@@ -93,7 +93,7 @@
         self.init_db()
         f = dbm.open(_fname, 'r')
         key = "a".encode("ascii")
-        assert(key in f)
+        self.assertIn(key, f)
         assert(f[key] == b"Python:")
         f.close()
 
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 57b69e6..797b887 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1654,7 +1654,7 @@
         self.assertNotIn(-1, c1)
         for i in range(10):
             self.assertIn(i, c1)
-        self.assertFalse(10 in c1)
+        self.assertNotIn(10, c1)
         # Test the default behavior for dynamic classes
         class D(object):
             def __getitem__(self, i):
@@ -1677,7 +1677,7 @@
         self.assertNotIn(-1, d1)
         for i in range(10):
             self.assertIn(i, d1)
-        self.assertFalse(10 in d1)
+        self.assertNotIn(10, d1)
         # Test overridden behavior
         class Proxy(object):
             def __init__(self, x):
@@ -1721,10 +1721,10 @@
         self.assertEqual(str(p0), "Proxy:0")
         self.assertEqual(repr(p0), "Proxy(0)")
         p10 = Proxy(range(10))
-        self.assertFalse(-1 in p10)
+        self.assertNotIn(-1, p10)
         for i in range(10):
             self.assertIn(i, p10)
-        self.assertFalse(10 in p10)
+        self.assertNotIn(10, p10)
 
     def test_weakrefs(self):
         # Testing weak references...
diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py
index 919fce8..c04d700 100644
--- a/Lib/test/test_dict.py
+++ b/Lib/test/test_dict.py
@@ -34,9 +34,7 @@
         self.assertEqual(set(d.keys()), set())
         d = {'a': 1, 'b': 2}
         k = d.keys()
-        self.assertTrue('a' in d)
         self.assertIn('a', d)
-        self.assertTrue('b' in d)
         self.assertIn('b', d)
         self.assertRaises(TypeError, d.keys, None)
         self.assertEqual(repr(dict(a=1).keys()), "dict_keys(['a'])")
@@ -60,15 +58,12 @@
 
     def test_contains(self):
         d = {}
+        self.assertNotIn('a', d)
         self.assertTrue(not ('a' in d))
         self.assertTrue('a' not in d)
-        self.assertNotIn('a', d)
         d = {'a': 1, 'b': 2}
-        self.assertTrue('a' in d)
         self.assertIn('a', d)
-        self.assertTrue('b' in d)
         self.assertIn('b', d)
-        self.assertTrue('c' not in d)
         self.assertNotIn('c', d)
 
         self.assertRaises(TypeError, d.__contains__)
@@ -524,9 +519,7 @@
         d = D({1: 2, 3: 4})
         self.assertEqual(d[1], 2)
         self.assertEqual(d[3], 4)
-        self.assertTrue(2 not in d)
         self.assertNotIn(2, d)
-        self.assertTrue(2 not in d.keys())
         self.assertNotIn(2, d.keys())
         self.assertEqual(d[2], 42)
         class E(dict):
diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index d82dc5a..3eda2bd 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -118,8 +118,8 @@
 
     def test_opmap(self):
         self.assertEqual(dis.opmap["STOP_CODE"], 0)
-        self.assertEqual(dis.opmap["LOAD_CONST"] in dis.hasconst, True)
-        self.assertEqual(dis.opmap["STORE_NAME"] in dis.hasname, True)
+        self.assertIn(dis.opmap["LOAD_CONST"], dis.hasconst)
+        self.assertIn(dis.opmap["STORE_NAME"], dis.hasname)
 
     def test_opname(self):
         self.assertEqual(dis.opname[dis.opmap["LOAD_FAST"]], "LOAD_FAST")
diff --git a/Lib/test/test_docxmlrpc.py b/Lib/test/test_docxmlrpc.py
index d48058c..d0b604c 100644
--- a/Lib/test/test_docxmlrpc.py
+++ b/Lib/test/test_docxmlrpc.py
@@ -18,8 +18,8 @@
         serv.set_server_title("DocXMLRPCServer Test Documentation")
         serv.set_server_name("DocXMLRPCServer Test Docs")
         serv.set_server_documentation(
-"""This is an XML-RPC server's documentation, but the server can be used by
-POSTing to /RPC2. Try self.add, too.""")
+            "This is an XML-RPC server's documentation, but the server "
+            "can be used by POSTing to /RPC2. Try self.add, too.")
 
         # Create and register classes and functions
         class TestClass(object):
@@ -106,9 +106,9 @@
         self.client.request("GET", "/")
         response = self.client.getresponse()
 
-        self.assertTrue(
-b"""<dl><dt><a name="-&lt;lambda&gt;"><strong>&lt;lambda&gt;</strong></a>(x, y)</dt></dl>"""
-            in response.read())
+        self.assertIn((b'<dl><dt><a name="-&lt;lambda&gt;"><strong>'
+                       b'&lt;lambda&gt;</strong></a>(x, y)</dt></dl>'),
+                      response.read())
 
     def test_autolinking(self):
         """Test that the server correctly automatically wraps references to PEPS
@@ -120,9 +120,17 @@
         self.client.request("GET", "/")
         response = self.client.getresponse().read()
 
-        self.assertTrue( # This is ugly ... how can it be made better?
-b"""<dl><dt><a name="-add"><strong>add</strong></a>(x, y)</dt><dd><tt>Add&nbsp;two&nbsp;instances&nbsp;together.&nbsp;This&nbsp;follows&nbsp;<a href="http://www.python.org/dev/peps/pep-0008/">PEP008</a>,&nbsp;but&nbsp;has&nbsp;nothing<br>\nto&nbsp;do&nbsp;with&nbsp;<a href="http://www.rfc-editor.org/rfc/rfc1952.txt">RFC1952</a>.&nbsp;Case&nbsp;should&nbsp;matter:&nbsp;pEp008&nbsp;and&nbsp;rFC1952.&nbsp;&nbsp;Things<br>\nthat&nbsp;start&nbsp;with&nbsp;http&nbsp;and&nbsp;ftp&nbsp;should&nbsp;be&nbsp;auto-linked,&nbsp;too:<br>\n<a href="http://google.com">http://google.com</a>.</tt></dd></dl>"""
-          in response, response)
+        self.assertIn(
+            (b'<dl><dt><a name="-add"><strong>add</strong></a>(x, y)</dt><dd>'
+             b'<tt>Add&nbsp;two&nbsp;instances&nbsp;together.&nbsp;This&nbsp;'
+             b'follows&nbsp;<a href="http://www.python.org/dev/peps/pep-0008/">'
+             b'PEP008</a>,&nbsp;but&nbsp;has&nbsp;nothing<br>\nto&nbsp;do&nbsp;'
+             b'with&nbsp;<a href="http://www.rfc-editor.org/rfc/rfc1952.txt">'
+             b'RFC1952</a>.&nbsp;Case&nbsp;should&nbsp;matter:&nbsp;pEp008&nbsp;'
+             b'and&nbsp;rFC1952.&nbsp;&nbsp;Things<br>\nthat&nbsp;start&nbsp;'
+             b'with&nbsp;http&nbsp;and&nbsp;ftp&nbsp;should&nbsp;be&nbsp;'
+             b'auto-linked,&nbsp;too:<br>\n<a href="http://google.com">'
+             b'http://google.com</a>.</tt></dd></dl>'), response)
 
     def test_system_methods(self):
         """Test the precense of three consecutive system.* methods.
@@ -133,8 +141,26 @@
         self.client.request("GET", "/")
         response = self.client.getresponse().read()
 
-        self.assertTrue(
-b"""<dl><dt><a name="-system.methodHelp"><strong>system.methodHelp</strong></a>(method_name)</dt><dd><tt><a href="#-system.methodHelp">system.methodHelp</a>(\'add\')&nbsp;=&gt;&nbsp;"Adds&nbsp;two&nbsp;integers&nbsp;together"<br>\n&nbsp;<br>\nReturns&nbsp;a&nbsp;string&nbsp;containing&nbsp;documentation&nbsp;for&nbsp;the&nbsp;specified&nbsp;method.</tt></dd></dl>\n<dl><dt><a name="-system.methodSignature"><strong>system.methodSignature</strong></a>(method_name)</dt><dd><tt><a href="#-system.methodSignature">system.methodSignature</a>(\'add\')&nbsp;=&gt;&nbsp;[double,&nbsp;int,&nbsp;int]<br>\n&nbsp;<br>\nReturns&nbsp;a&nbsp;list&nbsp;describing&nbsp;the&nbsp;signature&nbsp;of&nbsp;the&nbsp;method.&nbsp;In&nbsp;the<br>\nabove&nbsp;example,&nbsp;the&nbsp;add&nbsp;method&nbsp;takes&nbsp;two&nbsp;integers&nbsp;as&nbsp;arguments<br>\nand&nbsp;returns&nbsp;a&nbsp;double&nbsp;result.<br>\n&nbsp;<br>\nThis&nbsp;server&nbsp;does&nbsp;NOT&nbsp;support&nbsp;system.methodSignature.</tt></dd></dl>\n<dl><dt><a name="-test_method"><strong>test_method</strong></a>(arg)</dt><dd><tt>Test&nbsp;method\'s&nbsp;docs.&nbsp;This&nbsp;method&nbsp;truly&nbsp;does&nbsp;very&nbsp;little.</tt></dd></dl>""" in response)
+        self.assertIn(
+            (b'<dl><dt><a name="-system.methodHelp"><strong>system.methodHelp'
+             b'</strong></a>(method_name)</dt><dd><tt><a href="#-system.method'
+             b'Help">system.methodHelp</a>(\'add\')&nbsp;=&gt;&nbsp;"Adds&nbsp;'
+             b'two&nbsp;integers&nbsp;together"<br>\n&nbsp;<br>\nReturns&nbsp;a'
+             b'&nbsp;string&nbsp;containing&nbsp;documentation&nbsp;for&nbsp;'
+             b'the&nbsp;specified&nbsp;method.</tt></dd></dl>\n<dl><dt><a name'
+             b'="-system.methodSignature"><strong>system.methodSignature</strong>'
+             b'</a>(method_name)</dt><dd><tt><a href="#-system.methodSignature">'
+             b'system.methodSignature</a>(\'add\')&nbsp;=&gt;&nbsp;[double,&nbsp;'
+             b'int,&nbsp;int]<br>\n&nbsp;<br>\nReturns&nbsp;a&nbsp;list&nbsp;'
+             b'describing&nbsp;the&nbsp;signature&nbsp;of&nbsp;the&nbsp;method.'
+             b'&nbsp;In&nbsp;the<br>\nabove&nbsp;example,&nbsp;the&nbsp;add&nbsp;'
+             b'method&nbsp;takes&nbsp;two&nbsp;integers&nbsp;as&nbsp;arguments'
+             b'<br>\nand&nbsp;returns&nbsp;a&nbsp;double&nbsp;result.<br>\n&nbsp;'
+             b'<br>\nThis&nbsp;server&nbsp;does&nbsp;NOT&nbsp;support&nbsp;system'
+             b'.methodSignature.</tt></dd></dl>\n<dl><dt><a name="-test_method">'
+             b'<strong>test_method</strong></a>(arg)</dt><dd><tt>Test&nbsp;'
+             b'method\'s&nbsp;docs.&nbsp;This&nbsp;method&nbsp;truly&nbsp;does'
+             b'&nbsp;very&nbsp;little.</tt></dd></dl>'), response)
 
     def test_autolink_dotted_methods(self):
         """Test that selfdot values are made strong automatically in the
@@ -142,8 +168,8 @@
         self.client.request("GET", "/")
         response = self.client.getresponse()
 
-        self.assertTrue(b"""Try&nbsp;self.<strong>add</strong>,&nbsp;too.""" in
-            response.read())
+        self.assertIn(b"""Try&nbsp;self.<strong>add</strong>,&nbsp;too.""",
+                      response.read())
 
 def test_main():
     support.run_unittest(DocXMLRPCHTTPGETServer)
diff --git a/Lib/test/test_errno.py b/Lib/test/test_errno.py
index 80edcc6..621335c 100755
--- a/Lib/test/test_errno.py
+++ b/Lib/test/test_errno.py
@@ -28,8 +28,8 @@
     def test_attributes_in_errorcode(self):
         for attribute in errno.__dict__.keys():
             if attribute.isupper():
-                self.assertTrue(getattr(errno, attribute) in errno.errorcode,
-                             'no %s attr in errno.errorcode' % attribute)
+                self.assertIn(getattr(errno, attribute), errno.errorcode,
+                              'no %s attr in errno.errorcode' % attribute)
 
 
 def test_main():
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index c3be3f3..e9c2c4f 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -413,7 +413,7 @@
         except Exception as e:
             self.assertTrue(e)
             del e
-        self.assertFalse('e' in locals())
+        self.assertNotIn('e', locals())
 
     def testExceptionCleanupState(self):
         # Make sure exception state is cleaned up as soon as the except
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index db397ce..0538b0c 100644
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -214,16 +214,11 @@
         floats = (INF, -INF, 0.0, 1.0, NAN)
         for f in floats:
             self.assertIn(f, [f])
-            self.assertTrue(f in [f], "'%r' not in []" % f)
             self.assertIn(f, (f,))
-            self.assertTrue(f in (f,), "'%r' not in ()" % f)
             self.assertIn(f, {f})
-            self.assertTrue(f in {f}, "'%r' not in set()" % f)
             self.assertIn(f, {f: None})
-            self.assertTrue(f in {f: None}, "'%r' not in {}" % f)
             self.assertEqual([f].count(f), 1, "[].count('%r') != 1" % f)
             self.assertIn(f, floats)
-            self.assertTrue(f in floats, "'%r' not in container" % f)
 
         for f in floats:
             # nonidentical containers, same type, same contents
@@ -459,10 +454,10 @@
         float.__setformat__('float', self.save_formats['float'])
 
     def test_getformat(self):
-        self.assertTrue(float.__getformat__('double') in
-                     ['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
-        self.assertTrue(float.__getformat__('float') in
-                     ['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
+        self.assertIn(float.__getformat__('double'),
+                      ['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
+        self.assertIn(float.__getformat__('float'),
+                      ['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
         self.assertRaises(ValueError, float.__getformat__, 'chicken')
         self.assertRaises(TypeError, float.__getformat__, 1)
 
diff --git a/Lib/test/test_http_cookiejar.py b/Lib/test/test_http_cookiejar.py
index f244b2b..1c047b4 100644
--- a/Lib/test/test_http_cookiejar.py
+++ b/Lib/test/test_http_cookiejar.py
@@ -901,8 +901,7 @@
         url = "http://foo.bar.com/"
         interact_2965(c, url, "spam=eggs; Version=1")
         h = interact_2965(c, url)
-        self.assertTrue("Path" not in h,
-                     "absent path returned with path present")
+        self.assertNotIn("Path", h, "absent path returned with path present")
 
         c = CookieJar(pol)
         url = "http://foo.bar.com/"
@@ -917,8 +916,7 @@
         url = "http://foo.bar.com/"
         interact_2965(c, url, "spam=eggs; Version=1")
         h = interact_2965(c, url)
-        self.assertTrue("Port" not in h,
-                     "absent port returned with port present")
+        self.assertNotIn("Port", h, "absent port returned with port present")
 
         c = CookieJar(pol)
         url = "http://foo.bar.com/"
@@ -931,16 +929,16 @@
         url = "http://foo.bar.com/"
         interact_2965(c, url, 'spam=eggs; Version=1; Port="80"')
         h = interact_2965(c, url)
-        self.assertTrue('$Port="80"' in h,
-                     "port with single value not returned with single value")
+        self.assertIn('$Port="80"', h,
+                      "port with single value not returned with single value")
 
         c = CookieJar(pol)
         url = "http://foo.bar.com/"
         interact_2965(c, url, 'spam=eggs; Version=1; Port="80,8080"')
         h = interact_2965(c, url)
-        self.assertTrue('$Port="80,8080"' in h,
-                     "port with multiple values not returned with multiple "
-                     "values")
+        self.assertIn('$Port="80,8080"', h,
+                      "port with multiple values not returned with multiple "
+                      "values")
 
     def test_no_return_comment(self):
         c = CookieJar(DefaultCookiePolicy(rfc2965=True))
@@ -1105,8 +1103,8 @@
         c.add_cookie_header(req)
 
         h = req.get_header("Cookie")
-        self.assertTrue("PART_NUMBER=ROCKET_LAUNCHER_0001" in h and
-                     "CUSTOMER=WILE_E_COYOTE" in h)
+        self.assertIn("PART_NUMBER=ROCKET_LAUNCHER_0001", h)
+        self.assertIn("CUSTOMER=WILE_E_COYOTE", h)
 
         headers.append('Set-Cookie: SHIPPING=FEDEX; path=/foo')
         res = FakeResponse(headers, "http://www.acme.com")
@@ -1116,17 +1114,17 @@
         c.add_cookie_header(req)
 
         h = req.get_header("Cookie")
-        self.assertTrue("PART_NUMBER=ROCKET_LAUNCHER_0001" in h and
-                     "CUSTOMER=WILE_E_COYOTE" in h and
-                     "SHIPPING=FEDEX" not in h)
+        self.assertIn("PART_NUMBER=ROCKET_LAUNCHER_0001", h)
+        self.assertIn("CUSTOMER=WILE_E_COYOTE", h)
+        self.assertNotIn("SHIPPING=FEDEX", h)
 
         req = urllib.request.Request("http://www.acme.com/foo/")
         c.add_cookie_header(req)
 
         h = req.get_header("Cookie")
-        self.assertTrue(("PART_NUMBER=ROCKET_LAUNCHER_0001" in h and
-                      "CUSTOMER=WILE_E_COYOTE" in h and
-                      h.startswith("SHIPPING=FEDEX;")))
+        self.assertIn("PART_NUMBER=ROCKET_LAUNCHER_0001", h)
+        self.assertIn("CUSTOMER=WILE_E_COYOTE", h)
+        self.assertTrue(h.startswith("SHIPPING=FEDEX;"))
 
     def test_netscape_example_2(self):
         # Second Example transaction sequence:
@@ -1344,8 +1342,8 @@
         # the server.
 
         cookie = interact_2965(c, "http://www.acme.com/acme/parts/")
-        self.assertTrue("Rocket_Launcher_0001" in cookie and
-                     "Riding_Rocket_0023" not in cookie)
+        self.assertIn("Rocket_Launcher_0001", cookie)
+        self.assertNotIn("Riding_Rocket_0023", cookie)
 
     def test_rejection(self):
         # Test rejection of Set-Cookie2 responses based on domain, path, port.
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index d7e5e38..67d76be 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -474,8 +474,8 @@
         self.assertIn(('s', 'static method', A), attrs, 'missing static method')
         self.assertIn(('c', 'class method', A), attrs, 'missing class method')
         self.assertIn(('p', 'property', A), attrs, 'missing property')
-        self.assertTrue(('m', 'method', A) in attrs,
-            'missing plain method: %r' % attrs)
+        self.assertIn(('m', 'method', A), attrs,
+                      'missing plain method: %r' % attrs)
         self.assertIn(('m1', 'method', A), attrs, 'missing plain method')
         self.assertIn(('datablob', 'data', A), attrs, 'missing data')
 
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index 16e65ca..553eacf 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -1405,7 +1405,7 @@
                 Subclass(newarg=1)
             except TypeError as err:
                 # we expect type errors because of wrong argument count
-                self.assertFalse("does not take keyword arguments" in err.args[0])
+                self.assertNotIn("does not take keyword arguments", err.args[0])
 
 
 libreftest = """ Doctest for examples in the library reference: libitertools.tex
diff --git a/Lib/test/test_multibytecodec.py b/Lib/test/test_multibytecodec.py
index b482b39..e4e86ff 100644
--- a/Lib/test/test_multibytecodec.py
+++ b/Lib/test/test_multibytecodec.py
@@ -242,7 +242,7 @@
         self.assertEqual(iso2022jp2.decode('iso2022-jp-2'), uni)
 
     def test_iso2022_jp_g0(self):
-        self.assertFalse(b'\x0e' in '\N{SOFT HYPHEN}'.encode('iso-2022-jp-2'))
+        self.assertNotIn(b'\x0e', '\N{SOFT HYPHEN}'.encode('iso-2022-jp-2'))
         for encoding in ('iso-2022-jp-2004', 'iso-2022-jp-3'):
             e = '\u3406'.encode(encoding)
             self.assertFalse(any(x > 0x80 for x in e))
diff --git a/Lib/test/test_pep352.py b/Lib/test/test_pep352.py
index a2b4ec8..558cdb5 100644
--- a/Lib/test/test_pep352.py
+++ b/Lib/test/test_pep352.py
@@ -38,8 +38,8 @@
                 last_exc = getattr(builtins, superclass_name)
             except AttributeError:
                 self.fail("base class %s not a built-in" % superclass_name)
-            self.assertTrue(superclass_name in exc_set,
-                            '%s not found' % superclass_name)
+            self.assertIn(superclass_name, exc_set,
+                          '%s not found' % superclass_name)
             exc_set.discard(superclass_name)
             superclasses = []  # Loop will insert base exception
             last_depth = 0
diff --git a/Lib/test/test_pkgimport.py b/Lib/test/test_pkgimport.py
index 60f5c32..a9a475c 100644
--- a/Lib/test/test_pkgimport.py
+++ b/Lib/test/test_pkgimport.py
@@ -51,9 +51,9 @@
         self.rewrite_file('for')
         try: __import__(self.module_name)
         except SyntaxError: pass
-        else: raise RuntimeError('Failed to induce SyntaxError')
-        self.assertTrue(self.module_name not in sys.modules and
-                     not hasattr(sys.modules[self.package_name], 'foo'))
+        else: raise RuntimeError('Failed to induce SyntaxError') # self.fail()?
+        self.assertNotIn(self.module_name, sys.modules)
+        self.assertFalse(hasattr(sys.modules[self.package_name], 'foo'))
 
         # ...make up a variable name that isn't bound in __builtins__
         var = 'a'
diff --git a/Lib/test/test_profile.py b/Lib/test/test_profile.py
index 243a322..699fe4a 100755
--- a/Lib/test/test_profile.py
+++ b/Lib/test/test_profile.py
@@ -72,7 +72,7 @@
             stats = pstats.Stats(prof, stream=s)
             stats.print_stats()
             res = s.getvalue()
-            self.assertTrue(self.expected_max_output in res,
+            self.assertIn(self.expected_max_output, res,
                 "Profiling {0!r} didn't report max:\n{1}".format(stmt, res))
 
 
diff --git a/Lib/test/test_pyclbr.py b/Lib/test/test_pyclbr.py
index 06f3338..f1cb51f 100644
--- a/Lib/test/test_pyclbr.py
+++ b/Lib/test/test_pyclbr.py
@@ -41,7 +41,6 @@
         if key not in obj:
             print("***",key, file=sys.stderr)
         self.assertIn(key, obj)
-        self.assertTrue(key in obj, "%r in %r" % (key, obj))
 
     def assertEqualsOrIgnored(self, a, b, ignore):
         ''' succeed iff a == b or a in ignore or b in ignore '''
diff --git a/Lib/test/test_range.py b/Lib/test/test_range.py
index d9bf5a0..812b73d 100644
--- a/Lib/test/test_range.py
+++ b/Lib/test/test_range.py
@@ -126,7 +126,7 @@
         class C2:
             def __int__(self): return 1
             def __index__(self): return 1
-        self.assertFalse(C2() in range(3))
+        self.assertNotIn(C2(), range(3))
         # ..except if explicitly told so.
         self.assertIn(int(C2()), range(3))
 
@@ -140,32 +140,32 @@
     def test_strided_limits(self):
         r = range(0, 101, 2)
         self.assertIn(0, r)
-        self.assertFalse(1 in r)
+        self.assertNotIn(1, r)
         self.assertIn(2, r)
-        self.assertFalse(99 in r)
+        self.assertNotIn(99, r)
         self.assertIn(100, r)
-        self.assertFalse(101 in r)
+        self.assertNotIn(101, r)
 
         r = range(0, -20, -1)
         self.assertIn(0, r)
         self.assertIn(-1, r)
         self.assertIn(-19, r)
-        self.assertFalse(-20 in r)
+        self.assertNotIn(-20, r)
 
         r = range(0, -20, -2)
         self.assertIn(-18, r)
-        self.assertFalse(-19 in r)
-        self.assertFalse(-20 in r)
+        self.assertNotIn(-19, r)
+        self.assertNotIn(-20, r)
 
     def test_empty(self):
         r = range(0)
-        self.assertFalse(0 in r)
-        self.assertFalse(1 in r)
+        self.assertNotIn(0, r)
+        self.assertNotIn(1, r)
 
         r = range(0, -10)
-        self.assertFalse(0 in r)
-        self.assertFalse(-1 in r)
-        self.assertFalse(1 in r)
+        self.assertNotIn(0, r)
+        self.assertNotIn(-1, r)
+        self.assertNotIn(1, r)
 
     def test_range_iterators(self):
         # exercise 'fast' iterators, that use a rangeiterobject internally.
diff --git a/Lib/test/test_sax.py b/Lib/test/test_sax.py
index c920ad3..781cf51 100644
--- a/Lib/test/test_sax.py
+++ b/Lib/test/test_sax.py
@@ -30,7 +30,7 @@
         self.assertEquals(attrs.getNames(), [])
         self.assertEquals(attrs.getQNames(), [])
         self.assertEquals(len(attrs), 0)
-        self.assertFalse("attr" in attrs)
+        self.assertNotIn("attr", attrs)
         self.assertEquals(list(attrs.keys()), [])
         self.assertEquals(attrs.get("attrs"), None)
         self.assertEquals(attrs.get("attrs", 25), 25)
@@ -47,7 +47,7 @@
         self.assertEquals(attrs.getNames(), [])
         self.assertEquals(attrs.getQNames(), [])
         self.assertEquals(len(attrs), 0)
-        self.assertFalse((ns_uri, "attr") in attrs)
+        self.assertNotIn((ns_uri, "attr"), attrs)
         self.assertEquals(list(attrs.keys()), [])
         self.assertEquals(attrs.get((ns_uri, "attr")), None)
         self.assertEquals(attrs.get((ns_uri, "attr"), 25), 25)
diff --git a/Lib/test/test_site.py b/Lib/test/test_site.py
index f785319..0fde46a 100644
--- a/Lib/test/test_site.py
+++ b/Lib/test/test_site.py
@@ -63,14 +63,14 @@
         dir_set = site._init_pathinfo()
         for entry in [site.makepath(path)[1] for path in sys.path
                         if path and os.path.isdir(path)]:
-            self.assertTrue(entry in dir_set,
-                            "%s from sys.path not found in set returned "
-                            "by _init_pathinfo(): %s" % (entry, dir_set))
+            self.assertIn(entry, dir_set,
+                          "%s from sys.path not found in set returned "
+                          "by _init_pathinfo(): %s" % (entry, dir_set))
 
     def pth_file_tests(self, pth_file):
         """Contain common code for testing results of reading a .pth file"""
-        self.assertTrue(pth_file.imported in sys.modules,
-                "%s not in sys.modules" % pth_file.imported)
+        self.assertIn(pth_file.imported, sys.modules,
+                      "%s not in sys.modules" % pth_file.imported)
         self.assertIn(site.makepath(pth_file.good_dir_path)[0], sys.path)
         self.assertFalse(os.path.exists(pth_file.bad_dir_path))
 
diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py
index e0263b4..9f1bb44 100644
--- a/Lib/test/test_strptime.py
+++ b/Lib/test/test_strptime.py
@@ -36,8 +36,8 @@
         """
         strftime_output = time.strftime(directive, self.time_tuple).lower()
         comparison = testing[self.time_tuple[tuple_position]]
-        self.assertTrue(strftime_output in testing, "%s: not found in tuple" %
-                                                    error_msg)
+        self.assertIn(strftime_output, testing,
+                      "%s: not found in tuple" % error_msg)
         self.assertTrue(comparison == strftime_output,
                         "%s: position within tuple incorrect; %s != %s" %
                         (error_msg, comparison, strftime_output))
@@ -61,8 +61,8 @@
     def test_am_pm(self):
         # Make sure AM/PM representation done properly
         strftime_output = time.strftime("%p", self.time_tuple).lower()
-        self.assertTrue(strftime_output in self.LT_ins.am_pm,
-                        "AM/PM representation not in tuple")
+        self.assertIn(strftime_output, self.LT_ins.am_pm,
+                      "AM/PM representation not in tuple")
         if self.time_tuple[3] < 12: position = 0
         else: position = 1
         self.assertTrue(strftime_output == self.LT_ins.am_pm[position],
@@ -72,7 +72,7 @@
         # Make sure timezone is correct
         timezone = time.strftime("%Z", self.time_tuple).lower()
         if timezone:
-            self.assertTrue(timezone in self.LT_ins.timezone[0] or \
+            self.assertTrue(timezone in self.LT_ins.timezone[0] or
                             timezone in self.LT_ins.timezone[1],
                             "timezone %s not found in %s" %
                             (timezone, self.LT_ins.timezone))
@@ -133,9 +133,9 @@
         # Make sure any characters in the format string that might be taken as
         # regex syntax is escaped.
         pattern_string = self.time_re.pattern("\d+")
-        self.assertTrue(r"\\d\+" in pattern_string,
-                        "%s does not have re characters escaped properly" %
-                        pattern_string)
+        self.assertIn(r"\\d\+", pattern_string,
+                      "%s does not have re characters escaped properly" %
+                      pattern_string)
 
     def test_compile(self):
         # Check that compiled regex is correct
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)
diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py
index d296fac..0076c48 100644
--- a/Lib/test/test_tempfile.py
+++ b/Lib/test/test_tempfile.py
@@ -113,7 +113,7 @@
         for i in range(TEST_FILES):
             s = next(r)
             self.nameCheck(s, '', '', '')
-            self.assertFalse(s in dict)
+            self.assertNotIn(s, dict)
             dict[s] = 1
 
     def supports_iter(self):
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 0d43d42..8737c3d 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -350,7 +350,7 @@
                 t.start()
                 t.join()
                 l = enum()
-                self.assertFalse(t in l,
+                self.assertNotIn(t, l,
                     "#1703448 triggered after %d trials: %s" % (i, l))
         finally:
             sys.setswitchinterval(old_interval)
diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
index e4681c0..3db8864 100644
--- a/Lib/test/test_traceback.py
+++ b/Lib/test/test_traceback.py
@@ -131,7 +131,7 @@
             err_line = "raise RuntimeError('{0}')".format(message_ascii)
             err_msg = "RuntimeError: {0}".format(message_ascii)
 
-            self.assertTrue(("line %s" % lineno) in stdout[1],
+            self.assertIn(("line %s" % lineno), stdout[1],
                 "Invalid line number: {0!r} instead of {1}".format(
                     stdout[1], lineno))
             self.assertTrue(stdout[2].endswith(err_line),
@@ -271,7 +271,7 @@
         self.assertEquals(len(blocks), 3)
         self.assertEquals(blocks[1], cause_message)
         self.check_zero_div(blocks[0])
-        self.assert_('inner_raise() # Marker' in blocks[2])
+        self.assertIn('inner_raise() # Marker', blocks[2])
 
     def test_cause_recursive(self):
         def inner_raise():
diff --git a/Lib/test/test_unittest.py b/Lib/test/test_unittest.py
index 95febe1..13f7d2d 100644
--- a/Lib/test/test_unittest.py
+++ b/Lib/test/test_unittest.py
@@ -3035,7 +3035,7 @@
         try:
             self.assertRaises(KeyError, lambda: None)
         except self.failureException as e:
-            self.assert_("KeyError not raised" in str(e), str(e))
+            self.assertIn("KeyError not raised", str(e))
         else:
             self.fail("assertRaises() didn't fail")
         try:
@@ -3052,7 +3052,7 @@
             with self.assertRaises(KeyError):
                 pass
         except self.failureException as e:
-            self.assert_("KeyError not raised" in str(e), str(e))
+            self.assertIn("KeyError not raised", str(e))
         else:
             self.fail("assertRaises() didn't fail")
         try:
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index ad0c100..1f18190 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -731,7 +731,7 @@
         expect_somewhere = ["1st=1", "2nd=2", "3rd=3"]
         result = urllib.parse.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,
@@ -778,8 +778,7 @@
         result = urllib.parse.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('&'))
 
diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index 269451f..c43e1dd 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -1027,10 +1027,10 @@
         # Verify Proxy-Authorization gets tunneled to request.
         # httpsconn req_headers do not have the Proxy-Authorization header but
         # the req will have.
-        self.assertFalse(("Proxy-Authorization","FooBar") in
+        self.assertNotIn(("Proxy-Authorization","FooBar"),
                          https_handler.httpconn.req_headers)
-        self.assertTrue(("User-Agent","Grail") in
-                        https_handler.httpconn.req_headers)
+        self.assertIn(("User-Agent","Grail"),
+                      https_handler.httpconn.req_headers)
         self.assertIsNotNone(req._tunnel_host)
         self.assertEqual(req.get_host(), "proxy.example.com:3128")
         self.assertEqual(req.get_header("Proxy-authorization"),"FooBar")
diff --git a/Lib/test/test_weakref.py b/Lib/test/test_weakref.py
index 57a098d..a909428 100644
--- a/Lib/test/test_weakref.py
+++ b/Lib/test/test_weakref.py
@@ -169,8 +169,7 @@
         p[:] = [2, 3]
         self.assertEqual(len(L), 2)
         self.assertEqual(len(p), 2)
-        self.assertTrue(3 in p,
-                        "proxy didn't support __contains__() properly")
+        self.assertIn(3, p, "proxy didn't support __contains__() properly")
         p[1] = 5
         self.assertEqual(L[1], 5)
         self.assertEqual(p[1], 5)
@@ -961,13 +960,13 @@
         # weakref'ed objects and then return a new key/value pair corresponding
         # to the destroyed object.
         with testcontext() as (k, v):
-            self.assertFalse(k in dict)
+            self.assertNotIn(k, dict)
         with testcontext() as (k, v):
             self.assertRaises(KeyError, dict.__delitem__, k)
-        self.assertFalse(k in dict)
+        self.assertNotIn(k, dict)
         with testcontext() as (k, v):
             self.assertRaises(KeyError, dict.pop, k)
-        self.assertFalse(k in dict)
+        self.assertNotIn(k, dict)
         with testcontext() as (k, v):
             dict[k] = v
         self.assertEqual(dict[k], v)
@@ -1118,14 +1117,12 @@
         weakdict.update(dict)
         self.assertEqual(len(weakdict), len(dict))
         for k in weakdict.keys():
-            self.assertTrue(k in dict,
-                         "mysterious new key appeared in weak dict")
+            self.assertIn(k, dict, "mysterious new key appeared in weak dict")
             v = dict.get(k)
             self.assertTrue(v is weakdict[k])
             self.assertTrue(v is weakdict.get(k))
         for k in dict.keys():
-            self.assertTrue(k in weakdict,
-                         "original key disappeared in weak dict")
+            self.assertIn(k, weakdict, "original key disappeared in weak dict")
             v = dict[k]
             self.assertTrue(v is weakdict[k])
             self.assertTrue(v is weakdict.get(k))
diff --git a/Lib/test/test_weakset.py b/Lib/test/test_weakset.py
index 0136d75..fe68b66 100644
--- a/Lib/test/test_weakset.py
+++ b/Lib/test/test_weakset.py
@@ -35,7 +35,7 @@
         for method in dir(set):
             if method == 'test_c_api' or method.startswith('_'):
                 continue
-            self.assertTrue(method in weaksetmethods,
+            self.assertIn(method, weaksetmethods,
                          "WeakSet missing method " + method)
 
     def test_new_or_init(self):
@@ -342,10 +342,10 @@
                 it = None           # should commit all removals
 
         with testcontext() as u:
-            self.assertFalse(u in s)
+            self.assertNotIn(u, s)
         with testcontext() as u:
             self.assertRaises(KeyError, s.remove, u)
-        self.assertFalse(u in s)
+        self.assertNotIn(u, s)
         with testcontext() as u:
             s.add(u)
         self.assertIn(u, s)