diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index 74dccbf..424a25c 100755
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -9,6 +9,7 @@
 from weakref import proxy
 import array, cStringIO
 from cPickle import loads, dumps, HIGHEST_PROTOCOL
+import sys
 
 class ArraySubclass(array.array):
     pass
@@ -772,15 +773,15 @@
         s = None
         self.assertRaises(ReferenceError, len, p)
 
+    @unittest.skipUnless(hasattr(sys, 'getrefcount'),
+                         'test needs sys.getrefcount()')
     def test_bug_782369(self):
-        import sys
-        if hasattr(sys, "getrefcount"):
-            for i in range(10):
-                b = array.array('B', range(64))
-            rc = sys.getrefcount(10)
-            for i in range(10):
-                b = array.array('B', range(64))
-            self.assertEqual(rc, sys.getrefcount(10))
+        for i in range(10):
+            b = array.array('B', range(64))
+        rc = sys.getrefcount(10)
+        for i in range(10):
+            b = array.array('B', range(64))
+        self.assertEqual(rc, sys.getrefcount(10))
 
     def test_subclass_with_kwargs(self):
         # SF bug #1486663 -- this used to erroneously raise a TypeError
diff --git a/Lib/test/test_compileall.py b/Lib/test/test_compileall.py
index bff6989..d3a26db 100644
--- a/Lib/test/test_compileall.py
+++ b/Lib/test/test_compileall.py
@@ -31,11 +31,10 @@
         compare = struct.pack('<4sl', imp.get_magic(), mtime)
         return data, compare
 
+    @unittest.skipUnless(hasattr(os, 'stat'), 'test needs os.stat()')
     def recreation_check(self, metadata):
         """Check that compileall recreates bytecode when the new metadata is
         used."""
-        if not hasattr(os, 'stat'):
-            return
         py_compile.compile(self.source_path)
         self.assertEqual(*self.data())
         with open(self.bc_path, 'rb') as file:
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index 3f82665..d3c1dec 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -1014,78 +1014,77 @@
         dialect = sniffer.sniff(self.sample9)
         self.assertTrue(dialect.doublequote)
 
-if not hasattr(sys, "gettotalrefcount"):
-    if test_support.verbose: print "*** skipping leakage tests ***"
-else:
-    class NUL:
-        def write(s, *args):
-            pass
-        writelines = write
+class NUL:
+    def write(s, *args):
+        pass
+    writelines = write
 
-    class TestLeaks(unittest.TestCase):
-        def test_create_read(self):
-            delta = 0
-            lastrc = sys.gettotalrefcount()
-            for i in xrange(20):
-                gc.collect()
-                self.assertEqual(gc.garbage, [])
-                rc = sys.gettotalrefcount()
-                csv.reader(["a,b,c\r\n"])
-                csv.reader(["a,b,c\r\n"])
-                csv.reader(["a,b,c\r\n"])
-                delta = rc-lastrc
-                lastrc = rc
-            # if csv.reader() leaks, last delta should be 3 or more
-            self.assertEqual(delta < 3, True)
+@unittest.skipUnless(hasattr(sys, "gettotalrefcount"),
+                     'requires sys.gettotalrefcount()')
+class TestLeaks(unittest.TestCase):
+    def test_create_read(self):
+        delta = 0
+        lastrc = sys.gettotalrefcount()
+        for i in xrange(20):
+            gc.collect()
+            self.assertEqual(gc.garbage, [])
+            rc = sys.gettotalrefcount()
+            csv.reader(["a,b,c\r\n"])
+            csv.reader(["a,b,c\r\n"])
+            csv.reader(["a,b,c\r\n"])
+            delta = rc-lastrc
+            lastrc = rc
+        # if csv.reader() leaks, last delta should be 3 or more
+        self.assertEqual(delta < 3, True)
 
-        def test_create_write(self):
-            delta = 0
-            lastrc = sys.gettotalrefcount()
-            s = NUL()
-            for i in xrange(20):
-                gc.collect()
-                self.assertEqual(gc.garbage, [])
-                rc = sys.gettotalrefcount()
-                csv.writer(s)
-                csv.writer(s)
-                csv.writer(s)
-                delta = rc-lastrc
-                lastrc = rc
-            # if csv.writer() leaks, last delta should be 3 or more
-            self.assertEqual(delta < 3, True)
+    def test_create_write(self):
+        delta = 0
+        lastrc = sys.gettotalrefcount()
+        s = NUL()
+        for i in xrange(20):
+            gc.collect()
+            self.assertEqual(gc.garbage, [])
+            rc = sys.gettotalrefcount()
+            csv.writer(s)
+            csv.writer(s)
+            csv.writer(s)
+            delta = rc-lastrc
+            lastrc = rc
+        # if csv.writer() leaks, last delta should be 3 or more
+        self.assertEqual(delta < 3, True)
 
-        def test_read(self):
-            delta = 0
-            rows = ["a,b,c\r\n"]*5
-            lastrc = sys.gettotalrefcount()
-            for i in xrange(20):
-                gc.collect()
-                self.assertEqual(gc.garbage, [])
-                rc = sys.gettotalrefcount()
-                rdr = csv.reader(rows)
-                for row in rdr:
-                    pass
-                delta = rc-lastrc
-                lastrc = rc
-            # if reader leaks during read, delta should be 5 or more
-            self.assertEqual(delta < 5, True)
+    def test_read(self):
+        delta = 0
+        rows = ["a,b,c\r\n"]*5
+        lastrc = sys.gettotalrefcount()
+        for i in xrange(20):
+            gc.collect()
+            self.assertEqual(gc.garbage, [])
+            rc = sys.gettotalrefcount()
+            rdr = csv.reader(rows)
+            for row in rdr:
+                pass
+            delta = rc-lastrc
+            lastrc = rc
+        # if reader leaks during read, delta should be 5 or more
+        self.assertEqual(delta < 5, True)
 
-        def test_write(self):
-            delta = 0
-            rows = [[1,2,3]]*5
-            s = NUL()
-            lastrc = sys.gettotalrefcount()
-            for i in xrange(20):
-                gc.collect()
-                self.assertEqual(gc.garbage, [])
-                rc = sys.gettotalrefcount()
-                writer = csv.writer(s)
-                for row in rows:
-                    writer.writerow(row)
-                delta = rc-lastrc
-                lastrc = rc
-            # if writer leaks during write, last delta should be 5 or more
-            self.assertEqual(delta < 5, True)
+    def test_write(self):
+        delta = 0
+        rows = [[1,2,3]]*5
+        s = NUL()
+        lastrc = sys.gettotalrefcount()
+        for i in xrange(20):
+            gc.collect()
+            self.assertEqual(gc.garbage, [])
+            rc = sys.gettotalrefcount()
+            writer = csv.writer(s)
+            for row in rows:
+                writer.writerow(row)
+            delta = rc-lastrc
+            lastrc = rc
+        # if writer leaks during write, last delta should be 5 or more
+        self.assertEqual(delta < 5, True)
 
 # commented out for now - csv module doesn't yet support Unicode
 ## class TestUnicode(unittest.TestCase):
diff --git a/Lib/test/test_enumerate.py b/Lib/test/test_enumerate.py
index 6b9ff79..aac4da7 100644
--- a/Lib/test/test_enumerate.py
+++ b/Lib/test/test_enumerate.py
@@ -188,11 +188,10 @@
         self.assertRaises(TypeError, reversed)
         self.assertRaises(TypeError, reversed, [], 'extra')
 
+    @unittest.skipUnless(hasattr(sys, 'getrefcount'), 'test needs sys.getrefcount()')
     def test_bug1229429(self):
         # this bug was never in reversed, it was in
         # PyObject_CallMethod, and reversed_new calls that sometimes.
-        if not hasattr(sys, "getrefcount"):
-            return
         def f():
             pass
         r = f.__reversed__ = object()
diff --git a/Lib/test/test_ftplib.py b/Lib/test/test_ftplib.py
index 4060015..15cb336 100644
--- a/Lib/test/test_ftplib.py
+++ b/Lib/test/test_ftplib.py
@@ -15,7 +15,7 @@
 except ImportError:
     ssl = None
 
-from unittest import TestCase
+from unittest import TestCase, SkipTest, skipUnless
 from test import test_support
 from test.test_support import HOST, HOSTv6
 threading = test_support.import_module('threading')
@@ -579,8 +579,16 @@
         self.assertRaises(ftplib.Error, self.client.storlines, 'stor', f)
 
 
+@skipUnless(socket.has_ipv6, "IPv6 not enabled")
 class TestIPv6Environment(TestCase):
 
+    @classmethod
+    def setUpClass(cls):
+        try:
+            DummyFTPServer((HOST, 0), af=socket.AF_INET6)
+        except socket.error:
+            raise SkipTest("IPv6 not enabled")
+
     def setUp(self):
         self.server = DummyFTPServer((HOSTv6, 0), af=socket.AF_INET6)
         self.server.start()
@@ -615,6 +623,7 @@
         retr()
 
 
+@skipUnless(ssl, "SSL not available")
 class TestTLS_FTPClassMixin(TestFTPClass):
     """Repeat TestFTPClass tests starting the TLS layer for both control
     and data connections first.
@@ -630,6 +639,7 @@
         self.client.prot_p()
 
 
+@skipUnless(ssl, "SSL not available")
 class TestTLS_FTPClass(TestCase):
     """Specific TLS_FTP class tests."""
 
@@ -783,17 +793,9 @@
 
 
 def test_main():
-    tests = [TestFTPClass, TestTimeouts]
-    if socket.has_ipv6:
-        try:
-            DummyFTPServer((HOST, 0), af=socket.AF_INET6)
-        except socket.error:
-            pass
-        else:
-            tests.append(TestIPv6Environment)
-
-    if ssl is not None:
-        tests.extend([TestTLS_FTPClassMixin, TestTLS_FTPClass])
+    tests = [TestFTPClass, TestTimeouts,
+             TestIPv6Environment,
+             TestTLS_FTPClassMixin, TestTLS_FTPClass]
 
     thread_info = test_support.threading_setup()
     try:
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index 5e8e3c1..dbf6a58 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -772,10 +772,10 @@
         for msg in self._box:
             pass
 
+    @unittest.skipUnless(hasattr(os, 'umask'), 'test needs os.umask()')
+    @unittest.skipUnless(hasattr(os, 'stat'), 'test needs os.stat()')
     def test_file_permissions(self):
         # Verify that message files are created without execute permissions
-        if not hasattr(os, "stat") or not hasattr(os, "umask"):
-            return
         msg = mailbox.MaildirMessage(self._template % 0)
         orig_umask = os.umask(0)
         try:
@@ -786,12 +786,11 @@
         mode = os.stat(path).st_mode
         self.assertEqual(mode & 0111, 0)
 
+    @unittest.skipUnless(hasattr(os, 'umask'), 'test needs os.umask()')
+    @unittest.skipUnless(hasattr(os, 'stat'), 'test needs os.stat()')
     def test_folder_file_perms(self):
         # From bug #3228, we want to verify that the file created inside a Maildir
         # subfolder isn't marked as executable.
-        if not hasattr(os, "stat") or not hasattr(os, "umask"):
-            return
-
         orig_umask = os.umask(0)
         try:
             subfolder = self._box.add_folder('subfolder')
@@ -991,24 +990,25 @@
 
     _factory = lambda self, path, factory=None: mailbox.mbox(path, factory)
 
+    @unittest.skipUnless(hasattr(os, 'umask'), 'test needs os.umask()')
+    @unittest.skipUnless(hasattr(os, 'stat'), 'test needs os.stat()')
     def test_file_perms(self):
         # From bug #3228, we want to verify that the mailbox file isn't executable,
         # even if the umask is set to something that would leave executable bits set.
         # We only run this test on platforms that support umask.
-        if hasattr(os, 'umask') and hasattr(os, 'stat'):
-            try:
-                old_umask = os.umask(0077)
-                self._box.close()
-                os.unlink(self._path)
-                self._box = mailbox.mbox(self._path, create=True)
-                self._box.add('')
-                self._box.close()
-            finally:
-                os.umask(old_umask)
+        try:
+            old_umask = os.umask(0077)
+            self._box.close()
+            os.unlink(self._path)
+            self._box = mailbox.mbox(self._path, create=True)
+            self._box.add('')
+            self._box.close()
+        finally:
+            os.umask(old_umask)
 
-            st = os.stat(self._path)
-            perms = st.st_mode
-            self.assertFalse((perms & 0111)) # Execute bits should all be off.
+        st = os.stat(self._path)
+        perms = st.st_mode
+        self.assertFalse((perms & 0111)) # Execute bits should all be off.
 
     def test_terminating_newline(self):
         message = email.message.Message()
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index a8677ce..c7f5752 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -906,38 +906,37 @@
     # still fails this part of the test on some platforms.  For now, we only
     # *run* test_exceptions() in verbose mode, so that this isn't normally
     # tested.
+    @unittest.skipUnless(verbose, 'requires verbose mode')
+    def test_exceptions(self):
+        try:
+            x = math.exp(-1000000000)
+        except:
+            # mathmodule.c is failing to weed out underflows from libm, or
+            # we've got an fp format with huge dynamic range
+            self.fail("underflowing exp() should not have raised "
+                        "an exception")
+        if x != 0:
+            self.fail("underflowing exp() should have returned 0")
 
-    if verbose:
-        def test_exceptions(self):
-            try:
-                x = math.exp(-1000000000)
-            except:
-                # mathmodule.c is failing to weed out underflows from libm, or
-                # we've got an fp format with huge dynamic range
-                self.fail("underflowing exp() should not have raised "
-                          "an exception")
-            if x != 0:
-                self.fail("underflowing exp() should have returned 0")
+        # If this fails, probably using a strict IEEE-754 conforming libm, and x
+        # is +Inf afterwards.  But Python wants overflows detected by default.
+        try:
+            x = math.exp(1000000000)
+        except OverflowError:
+            pass
+        else:
+            self.fail("overflowing exp() didn't trigger OverflowError")
 
-            # If this fails, probably using a strict IEEE-754 conforming libm, and x
-            # is +Inf afterwards.  But Python wants overflows detected by default.
-            try:
-                x = math.exp(1000000000)
-            except OverflowError:
-                pass
-            else:
-                self.fail("overflowing exp() didn't trigger OverflowError")
-
-            # If this fails, it could be a puzzle.  One odd possibility is that
-            # mathmodule.c's macros are getting confused while comparing
-            # Inf (HUGE_VAL) to a NaN, and artificially setting errno to ERANGE
-            # as a result (and so raising OverflowError instead).
-            try:
-                x = math.sqrt(-1.0)
-            except ValueError:
-                pass
-            else:
-                self.fail("sqrt(-1) didn't raise ValueError")
+        # If this fails, it could be a puzzle.  One odd possibility is that
+        # mathmodule.c's macros are getting confused while comparing
+        # Inf (HUGE_VAL) to a NaN, and artificially setting errno to ERANGE
+        # as a result (and so raising OverflowError instead).
+        try:
+            x = math.sqrt(-1.0)
+        except ValueError:
+            pass
+        else:
+            self.fail("sqrt(-1) didn't raise ValueError")
 
     @requires_IEEE_754
     def test_testfile(self):
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 9fd2184..62c65bd 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -320,26 +320,25 @@
         mf.close()
         f.close()
 
+    @unittest.skipUnless(hasattr(os, "stat"), "needs os.stat()")
     def test_entire_file(self):
         # test mapping of entire file by passing 0 for map length
-        if hasattr(os, "stat"):
-            f = open(TESTFN, "w+")
+        f = open(TESTFN, "w+")
 
-            f.write(2**16 * 'm') # Arbitrary character
-            f.close()
+        f.write(2**16 * 'm') # Arbitrary character
+        f.close()
 
-            f = open(TESTFN, "rb+")
-            mf = mmap.mmap(f.fileno(), 0)
-            self.assertEqual(len(mf), 2**16, "Map size should equal file size.")
-            self.assertEqual(mf.read(2**16), 2**16 * "m")
-            mf.close()
-            f.close()
+        f = open(TESTFN, "rb+")
+        mf = mmap.mmap(f.fileno(), 0)
+        self.assertEqual(len(mf), 2**16, "Map size should equal file size.")
+        self.assertEqual(mf.read(2**16), 2**16 * "m")
+        mf.close()
+        f.close()
 
+    @unittest.skipUnless(hasattr(os, "stat"), "needs os.stat()")
     def test_length_0_offset(self):
         # Issue #10916: test mapping of remainder of file by passing 0 for
         # map length with an offset doesn't cause a segfault.
-        if not hasattr(os, "stat"):
-            self.skipTest("needs os.stat")
         # NOTE: allocation granularity is currently 65536 under Win64,
         # and therefore the minimum offset alignment.
         with open(TESTFN, "wb") as f:
@@ -352,12 +351,10 @@
             finally:
                 mf.close()
 
+    @unittest.skipUnless(hasattr(os, "stat"), "needs os.stat()")
     def test_length_0_large_offset(self):
         # Issue #10959: test mapping of a file by passing 0 for
         # map length with a large offset doesn't cause a segfault.
-        if not hasattr(os, "stat"):
-            self.skipTest("needs os.stat")
-
         with open(TESTFN, "wb") as f:
             f.write(115699 * b'm') # Arbitrary character
 
@@ -538,9 +535,8 @@
                 return mmap.mmap.__new__(klass, -1, *args, **kwargs)
         anon_mmap(PAGESIZE)
 
+    @unittest.skipUnless(hasattr(mmap, 'PROT_READ'), "needs mmap.PROT_READ")
     def test_prot_readonly(self):
-        if not hasattr(mmap, 'PROT_READ'):
-            return
         mapsize = 10
         open(TESTFN, "wb").write("a"*mapsize)
         f = open(TESTFN, "rb")
@@ -584,66 +580,68 @@
         m.seek(8)
         self.assertRaises(ValueError, m.write, "bar")
 
-    if os.name == 'nt':
-        def test_tagname(self):
-            data1 = "0123456789"
-            data2 = "abcdefghij"
-            assert len(data1) == len(data2)
+    @unittest.skipUnless(os.name == 'nt', 'requires Windows')
+    def test_tagname(self):
+        data1 = "0123456789"
+        data2 = "abcdefghij"
+        assert len(data1) == len(data2)
 
-            # Test same tag
-            m1 = mmap.mmap(-1, len(data1), tagname="foo")
-            m1[:] = data1
-            m2 = mmap.mmap(-1, len(data2), tagname="foo")
-            m2[:] = data2
-            self.assertEqual(m1[:], data2)
-            self.assertEqual(m2[:], data2)
-            m2.close()
-            m1.close()
+        # Test same tag
+        m1 = mmap.mmap(-1, len(data1), tagname="foo")
+        m1[:] = data1
+        m2 = mmap.mmap(-1, len(data2), tagname="foo")
+        m2[:] = data2
+        self.assertEqual(m1[:], data2)
+        self.assertEqual(m2[:], data2)
+        m2.close()
+        m1.close()
 
-            # Test different tag
-            m1 = mmap.mmap(-1, len(data1), tagname="foo")
-            m1[:] = data1
-            m2 = mmap.mmap(-1, len(data2), tagname="boo")
-            m2[:] = data2
-            self.assertEqual(m1[:], data1)
-            self.assertEqual(m2[:], data2)
-            m2.close()
-            m1.close()
+        # Test different tag
+        m1 = mmap.mmap(-1, len(data1), tagname="foo")
+        m1[:] = data1
+        m2 = mmap.mmap(-1, len(data2), tagname="boo")
+        m2[:] = data2
+        self.assertEqual(m1[:], data1)
+        self.assertEqual(m2[:], data2)
+        m2.close()
+        m1.close()
 
-        def test_crasher_on_windows(self):
-            # Should not crash (Issue 1733986)
-            m = mmap.mmap(-1, 1000, tagname="foo")
-            try:
-                mmap.mmap(-1, 5000, tagname="foo")[:] # same tagname, but larger size
-            except:
-                pass
-            m.close()
+    @unittest.skipUnless(os.name == 'nt', 'requires Windows')
+    def test_crasher_on_windows(self):
+        # Should not crash (Issue 1733986)
+        m = mmap.mmap(-1, 1000, tagname="foo")
+        try:
+            mmap.mmap(-1, 5000, tagname="foo")[:] # same tagname, but larger size
+        except:
+            pass
+        m.close()
 
-            # Should not crash (Issue 5385)
-            open(TESTFN, "wb").write("x"*10)
-            f = open(TESTFN, "r+b")
-            m = mmap.mmap(f.fileno(), 0)
-            f.close()
-            try:
-                m.resize(0) # will raise WindowsError
-            except:
-                pass
-            try:
-                m[:]
-            except:
-                pass
-            m.close()
+        # Should not crash (Issue 5385)
+        open(TESTFN, "wb").write("x"*10)
+        f = open(TESTFN, "r+b")
+        m = mmap.mmap(f.fileno(), 0)
+        f.close()
+        try:
+            m.resize(0) # will raise WindowsError
+        except:
+            pass
+        try:
+            m[:]
+        except:
+            pass
+        m.close()
 
-        def test_invalid_descriptor(self):
-            # socket file descriptors are valid, but out of range
-            # for _get_osfhandle, causing a crash when validating the
-            # parameters to _get_osfhandle.
-            s = socket.socket()
-            try:
-                with self.assertRaises(mmap.error):
-                    m = mmap.mmap(s.fileno(), 10)
-            finally:
-                s.close()
+    @unittest.skipUnless(os.name == 'nt', 'requires Windows')
+    def test_invalid_descriptor(self):
+        # socket file descriptors are valid, but out of range
+        # for _get_osfhandle, causing a crash when validating the
+        # parameters to _get_osfhandle.
+        s = socket.socket()
+        try:
+            with self.assertRaises(mmap.error):
+                m = mmap.mmap(s.fileno(), 10)
+        finally:
+            s.close()
 
 
 class LargeMmapTests(unittest.TestCase):
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 1d7e836..a35162f 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -83,9 +83,8 @@
         open(name, "w")
         self.files.append(name)
 
+    @unittest.skipUnless(hasattr(os, 'tempnam'), 'test needs os.tempnam()')
     def test_tempnam(self):
-        if not hasattr(os, "tempnam"):
-            return
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", "tempnam", RuntimeWarning,
                                     r"test_os$")
@@ -99,9 +98,8 @@
             self.assertTrue(os.path.basename(name)[:3] == "pfx")
             self.check_tempfile(name)
 
+    @unittest.skipUnless(hasattr(os, 'tmpfile'), 'test needs os.tmpfile()')
     def test_tmpfile(self):
-        if not hasattr(os, "tmpfile"):
-            return
         # As with test_tmpnam() below, the Windows implementation of tmpfile()
         # attempts to create a file in the root directory of the current drive.
         # On Vista and Server 2008, this test will always fail for normal users
@@ -150,9 +148,8 @@
             fp.close()
             self.assertTrue(s == "foobar")
 
+    @unittest.skipUnless(hasattr(os, 'tmpnam'), 'test needs os.tmpnam()')
     def test_tmpnam(self):
-        if not hasattr(os, "tmpnam"):
-            return
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", "tmpnam", RuntimeWarning,
                                     r"test_os$")
@@ -193,10 +190,8 @@
         os.unlink(self.fname)
         os.rmdir(test_support.TESTFN)
 
+    @unittest.skipUnless(hasattr(os, 'stat'), 'test needs os.stat()')
     def test_stat_attributes(self):
-        if not hasattr(os, "stat"):
-            return
-
         import stat
         result = os.stat(self.fname)
 
@@ -256,10 +251,8 @@
             pass
 
 
+    @unittest.skipUnless(hasattr(os, 'statvfs'), 'test needs os.statvfs()')
     def test_statvfs_attributes(self):
-        if not hasattr(os, "statvfs"):
-            return
-
         try:
             result = os.statvfs(self.fname)
         except OSError, e:
@@ -311,10 +304,10 @@
         st2 = os.stat(test_support.TESTFN)
         self.assertEqual(st2.st_mtime, int(st.st_mtime-delta))
 
-    # Restrict test to Win32, since there is no guarantee other
+    # Restrict tests to Win32, since there is no guarantee other
     # systems support centiseconds
-    if sys.platform == 'win32':
-        def get_file_system(path):
+    def get_file_system(path):
+        if sys.platform == 'win32':
             root = os.path.splitdrive(os.path.abspath(path))[0] + '\\'
             import ctypes
             kernel32 = ctypes.windll.kernel32
@@ -322,25 +315,31 @@
             if kernel32.GetVolumeInformationA(root, None, 0, None, None, None, buf, len(buf)):
                 return buf.value
 
-        if get_file_system(test_support.TESTFN) == "NTFS":
-            def test_1565150(self):
-                t1 = 1159195039.25
-                os.utime(self.fname, (t1, t1))
-                self.assertEqual(os.stat(self.fname).st_mtime, t1)
+    @unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
+    @unittest.skipUnless(get_file_system(support.TESTFN) == "NTFS",
+                         "requires NTFS")
+    def test_1565150(self):
+        t1 = 1159195039.25
+        os.utime(self.fname, (t1, t1))
+        self.assertEqual(os.stat(self.fname).st_mtime, t1)
 
-            def test_large_time(self):
-                t1 = 5000000000 # some day in 2128
-                os.utime(self.fname, (t1, t1))
-                self.assertEqual(os.stat(self.fname).st_mtime, t1)
+    @unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
+    @unittest.skipUnless(get_file_system(support.TESTFN) == "NTFS",
+                         "requires NTFS")
+    def test_large_time(self):
+        t1 = 5000000000 # some day in 2128
+        os.utime(self.fname, (t1, t1))
+        self.assertEqual(os.stat(self.fname).st_mtime, t1)
 
-        def test_1686475(self):
-            # Verify that an open file can be stat'ed
-            try:
-                os.stat(r"c:\pagefile.sys")
-            except WindowsError, e:
-                if e.errno == 2: # file does not exist; cannot run test
-                    return
-                self.fail("Could not stat pagefile.sys")
+    @unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
+    def test_1686475(self):
+        # Verify that an open file can be stat'ed
+        try:
+            os.stat(r"c:\pagefile.sys")
+        except WindowsError, e:
+            if e.errno == 2: # file does not exist; cannot run test
+                return
+            self.fail("Could not stat pagefile.sys")
 
 from test import mapping_tests
 
@@ -598,6 +597,7 @@
         self.assertRaises(ValueError, os.execvpe, 'notepad', [], None)
 
 
+@unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
 class Win32ErrorTests(unittest.TestCase):
     def test_rename(self):
         self.assertRaises(WindowsError, os.rename, test_support.TESTFN, test_support.TESTFN+".bak")
@@ -644,121 +644,118 @@
             self.fail("%r didn't raise a OSError with a bad file descriptor"
                       % f)
 
+    @unittest.skipUnless(hasattr(os, 'isatty'), 'test needs os.isatty()')
     def test_isatty(self):
-        if hasattr(os, "isatty"):
-            self.assertEqual(os.isatty(test_support.make_bad_fd()), False)
+        self.assertEqual(os.isatty(test_support.make_bad_fd()), False)
 
+    @unittest.skipUnless(hasattr(os, 'closerange'), 'test needs os.closerange()')
     def test_closerange(self):
-        if hasattr(os, "closerange"):
-            fd = test_support.make_bad_fd()
-            # Make sure none of the descriptors we are about to close are
-            # currently valid (issue 6542).
-            for i in range(10):
-                try: os.fstat(fd+i)
-                except OSError:
-                    pass
-                else:
-                    break
-            if i < 2:
-                raise unittest.SkipTest(
-                    "Unable to acquire a range of invalid file descriptors")
-            self.assertEqual(os.closerange(fd, fd + i-1), None)
+        fd = test_support.make_bad_fd()
+        # Make sure none of the descriptors we are about to close are
+        # currently valid (issue 6542).
+        for i in range(10):
+            try: os.fstat(fd+i)
+            except OSError:
+                pass
+            else:
+                break
+        if i < 2:
+            raise unittest.SkipTest(
+                "Unable to acquire a range of invalid file descriptors")
+        self.assertEqual(os.closerange(fd, fd + i-1), None)
 
+    @unittest.skipUnless(hasattr(os, 'dup2'), 'test needs os.dup2()')
     def test_dup2(self):
-        if hasattr(os, "dup2"):
-            self.check(os.dup2, 20)
+        self.check(os.dup2, 20)
 
+    @unittest.skipUnless(hasattr(os, 'fchmod'), 'test needs os.fchmod()')
     def test_fchmod(self):
-        if hasattr(os, "fchmod"):
-            self.check(os.fchmod, 0)
+        self.check(os.fchmod, 0)
 
+    @unittest.skipUnless(hasattr(os, 'fchown'), 'test needs os.fchown()')
     def test_fchown(self):
-        if hasattr(os, "fchown"):
-            self.check(os.fchown, -1, -1)
+        self.check(os.fchown, -1, -1)
 
+    @unittest.skipUnless(hasattr(os, 'fpathconf'), 'test needs os.fpathconf()')
     def test_fpathconf(self):
-        if hasattr(os, "fpathconf"):
-            self.check(os.fpathconf, "PC_NAME_MAX")
+        self.check(os.fpathconf, "PC_NAME_MAX")
 
+    @unittest.skipUnless(hasattr(os, 'ftruncate'), 'test needs os.ftruncate()')
     def test_ftruncate(self):
-        if hasattr(os, "ftruncate"):
-            self.check(os.ftruncate, 0)
+        self.check(os.ftruncate, 0)
 
+    @unittest.skipUnless(hasattr(os, 'lseek'), 'test needs os.lseek()')
     def test_lseek(self):
-        if hasattr(os, "lseek"):
-            self.check(os.lseek, 0, 0)
+        self.check(os.lseek, 0, 0)
 
+    @unittest.skipUnless(hasattr(os, 'read'), 'test needs os.read()')
     def test_read(self):
-        if hasattr(os, "read"):
-            self.check(os.read, 1)
+        self.check(os.read, 1)
 
+    @unittest.skipUnless(hasattr(os, 'tcsetpgrp'), 'test needs os.tcsetpgrp()')
     def test_tcsetpgrpt(self):
-        if hasattr(os, "tcsetpgrp"):
-            self.check(os.tcsetpgrp, 0)
+        self.check(os.tcsetpgrp, 0)
 
+    @unittest.skipUnless(hasattr(os, 'write'), 'test needs os.write()')
     def test_write(self):
-        if hasattr(os, "write"):
-            self.check(os.write, " ")
+        self.check(os.write, " ")
 
-if sys.platform != 'win32':
-    class Win32ErrorTests(unittest.TestCase):
-        pass
+@unittest.skipIf(sys.platform == "win32", "Posix specific tests")
+class PosixUidGidTests(unittest.TestCase):
+    @unittest.skipUnless(hasattr(os, 'setuid'), 'test needs os.setuid()')
+    def test_setuid(self):
+        if os.getuid() != 0:
+            self.assertRaises(os.error, os.setuid, 0)
+        self.assertRaises(OverflowError, os.setuid, 1<<32)
 
-    class PosixUidGidTests(unittest.TestCase):
-        if hasattr(os, 'setuid'):
-            def test_setuid(self):
-                if os.getuid() != 0:
-                    self.assertRaises(os.error, os.setuid, 0)
-                self.assertRaises(OverflowError, os.setuid, 1<<32)
+    @unittest.skipUnless(hasattr(os, 'setgid'), 'test needs os.setgid()')
+    def test_setgid(self):
+        if os.getuid() != 0:
+            self.assertRaises(os.error, os.setgid, 0)
+        self.assertRaises(OverflowError, os.setgid, 1<<32)
 
-        if hasattr(os, 'setgid'):
-            def test_setgid(self):
-                if os.getuid() != 0:
-                    self.assertRaises(os.error, os.setgid, 0)
-                self.assertRaises(OverflowError, os.setgid, 1<<32)
+    @unittest.skipUnless(hasattr(os, 'seteuid'), 'test needs os.seteuid()')
+    def test_seteuid(self):
+        if os.getuid() != 0:
+            self.assertRaises(os.error, os.seteuid, 0)
+        self.assertRaises(OverflowError, os.seteuid, 1<<32)
 
-        if hasattr(os, 'seteuid'):
-            def test_seteuid(self):
-                if os.getuid() != 0:
-                    self.assertRaises(os.error, os.seteuid, 0)
-                self.assertRaises(OverflowError, os.seteuid, 1<<32)
+    @unittest.skipUnless(hasattr(os, 'setegid'), 'test needs os.setegid()')
+    def test_setegid(self):
+        if os.getuid() != 0:
+            self.assertRaises(os.error, os.setegid, 0)
+        self.assertRaises(OverflowError, os.setegid, 1<<32)
 
-        if hasattr(os, 'setegid'):
-            def test_setegid(self):
-                if os.getuid() != 0:
-                    self.assertRaises(os.error, os.setegid, 0)
-                self.assertRaises(OverflowError, os.setegid, 1<<32)
+    @unittest.skipUnless(hasattr(os, 'setreuid'), 'test needs os.setreuid()')
+    def test_setreuid(self):
+        if os.getuid() != 0:
+            self.assertRaises(os.error, os.setreuid, 0, 0)
+        self.assertRaises(OverflowError, os.setreuid, 1<<32, 0)
+        self.assertRaises(OverflowError, os.setreuid, 0, 1<<32)
 
-        if hasattr(os, 'setreuid'):
-            def test_setreuid(self):
-                if os.getuid() != 0:
-                    self.assertRaises(os.error, os.setreuid, 0, 0)
-                self.assertRaises(OverflowError, os.setreuid, 1<<32, 0)
-                self.assertRaises(OverflowError, os.setreuid, 0, 1<<32)
+    @unittest.skipUnless(hasattr(os, 'setreuid'), 'test needs os.setreuid()')
+    def test_setreuid_neg1(self):
+        # Needs to accept -1.  We run this in a subprocess to avoid
+        # altering the test runner's process state (issue8045).
+        subprocess.check_call([
+                sys.executable, '-c',
+                'import os,sys;os.setreuid(-1,-1);sys.exit(0)'])
 
-            def test_setreuid_neg1(self):
-                # Needs to accept -1.  We run this in a subprocess to avoid
-                # altering the test runner's process state (issue8045).
-                subprocess.check_call([
-                        sys.executable, '-c',
-                        'import os,sys;os.setreuid(-1,-1);sys.exit(0)'])
+    @unittest.skipUnless(hasattr(os, 'setregid'), 'test needs os.setregid()')
+    def test_setregid(self):
+        if os.getuid() != 0:
+            self.assertRaises(os.error, os.setregid, 0, 0)
+        self.assertRaises(OverflowError, os.setregid, 1<<32, 0)
+        self.assertRaises(OverflowError, os.setregid, 0, 1<<32)
 
-        if hasattr(os, 'setregid'):
-            def test_setregid(self):
-                if os.getuid() != 0:
-                    self.assertRaises(os.error, os.setregid, 0, 0)
-                self.assertRaises(OverflowError, os.setregid, 1<<32, 0)
-                self.assertRaises(OverflowError, os.setregid, 0, 1<<32)
+    @unittest.skipUnless(hasattr(os, 'setregid'), 'test needs os.setregid()')
+    def test_setregid_neg1(self):
+        # Needs to accept -1.  We run this in a subprocess to avoid
+        # altering the test runner's process state (issue8045).
+        subprocess.check_call([
+                sys.executable, '-c',
+                'import os,sys;os.setregid(-1,-1);sys.exit(0)'])
 
-            def test_setregid_neg1(self):
-                # Needs to accept -1.  We run this in a subprocess to avoid
-                # altering the test runner's process state (issue8045).
-                subprocess.check_call([
-                        sys.executable, '-c',
-                        'import os,sys;os.setregid(-1,-1);sys.exit(0)'])
-else:
-    class PosixUidGidTests(unittest.TestCase):
-        pass
 
 @unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
 class Win32KillTests(unittest.TestCase):
diff --git a/Lib/test/test_poplib.py b/Lib/test/test_poplib.py
index 9505c22..e9b6daf 100644
--- a/Lib/test/test_poplib.py
+++ b/Lib/test/test_poplib.py
@@ -11,7 +11,7 @@
 import time
 import errno
 
-from unittest import TestCase
+from unittest import TestCase, skipUnless
 from test import test_support
 from test.test_support import HOST
 threading = test_support.import_module('threading')
@@ -263,17 +263,20 @@
             else:
                 DummyPOP3Handler.handle_read(self)
 
-    class TestPOP3_SSLClass(TestPOP3Class):
-        # repeat previous tests by using poplib.POP3_SSL
+requires_ssl = skipUnless(SUPPORTS_SSL, 'SSL not supported')
 
-        def setUp(self):
-            self.server = DummyPOP3Server((HOST, 0))
-            self.server.handler = DummyPOP3_SSLHandler
-            self.server.start()
-            self.client = poplib.POP3_SSL(self.server.host, self.server.port)
+@requires_ssl
+class TestPOP3_SSLClass(TestPOP3Class):
+    # repeat previous tests by using poplib.POP3_SSL
 
-        def test__all__(self):
-            self.assertIn('POP3_SSL', poplib.__all__)
+    def setUp(self):
+        self.server = DummyPOP3Server((HOST, 0))
+        self.server.handler = DummyPOP3_SSLHandler
+        self.server.start()
+        self.client = poplib.POP3_SSL(self.server.host, self.server.port)
+
+    def test__all__(self):
+        self.assertIn('POP3_SSL', poplib.__all__)
 
 
 class TestTimeouts(TestCase):
@@ -331,9 +334,8 @@
 
 
 def test_main():
-    tests = [TestPOP3Class, TestTimeouts]
-    if SUPPORTS_SSL:
-        tests.append(TestPOP3_SSLClass)
+    tests = [TestPOP3Class, TestTimeouts,
+             TestPOP3_SSLClass]
     thread_info = test_support.threading_setup()
     try:
         test_support.run_unittest(*tests)
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index b0a8cdf..b7f05b2 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -53,47 +53,55 @@
                     posix_func()
                     self.assertRaises(TypeError, posix_func, 1)
 
-    if hasattr(posix, 'getresuid'):
-        def test_getresuid(self):
-            user_ids = posix.getresuid()
-            self.assertEqual(len(user_ids), 3)
-            for val in user_ids:
-                self.assertGreaterEqual(val, 0)
+    @unittest.skipUnless(hasattr(posix, 'getresuid'),
+                         'test needs posix.getresuid()')
+    def test_getresuid(self):
+        user_ids = posix.getresuid()
+        self.assertEqual(len(user_ids), 3)
+        for val in user_ids:
+            self.assertGreaterEqual(val, 0)
 
-    if hasattr(posix, 'getresgid'):
-        def test_getresgid(self):
-            group_ids = posix.getresgid()
-            self.assertEqual(len(group_ids), 3)
-            for val in group_ids:
-                self.assertGreaterEqual(val, 0)
+    @unittest.skipUnless(hasattr(posix, 'getresgid'),
+                         'test needs posix.getresgid()')
+    def test_getresgid(self):
+        group_ids = posix.getresgid()
+        self.assertEqual(len(group_ids), 3)
+        for val in group_ids:
+            self.assertGreaterEqual(val, 0)
 
-    if hasattr(posix, 'setresuid'):
-        def test_setresuid(self):
-            current_user_ids = posix.getresuid()
-            self.assertIsNone(posix.setresuid(*current_user_ids))
-            # -1 means don't change that value.
-            self.assertIsNone(posix.setresuid(-1, -1, -1))
+    @unittest.skipUnless(hasattr(posix, 'setresuid'),
+                         'test needs posix.setresuid()')
+    def test_setresuid(self):
+        current_user_ids = posix.getresuid()
+        self.assertIsNone(posix.setresuid(*current_user_ids))
+        # -1 means don't change that value.
+        self.assertIsNone(posix.setresuid(-1, -1, -1))
 
-        def test_setresuid_exception(self):
-            # Don't do this test if someone is silly enough to run us as root.
-            current_user_ids = posix.getresuid()
-            if 0 not in current_user_ids:
-                new_user_ids = (current_user_ids[0]+1, -1, -1)
-                self.assertRaises(OSError, posix.setresuid, *new_user_ids)
+    @unittest.skipUnless(hasattr(posix, 'setresuid'),
+                         'test needs posix.setresuid()')
+    def test_setresuid_exception(self):
+        # Don't do this test if someone is silly enough to run us as root.
+        current_user_ids = posix.getresuid()
+        if 0 not in current_user_ids:
+            new_user_ids = (current_user_ids[0]+1, -1, -1)
+            self.assertRaises(OSError, posix.setresuid, *new_user_ids)
 
-    if hasattr(posix, 'setresgid'):
-        def test_setresgid(self):
-            current_group_ids = posix.getresgid()
-            self.assertIsNone(posix.setresgid(*current_group_ids))
-            # -1 means don't change that value.
-            self.assertIsNone(posix.setresgid(-1, -1, -1))
+    @unittest.skipUnless(hasattr(posix, 'setresgid'),
+                         'test needs posix.setresgid()')
+    def test_setresgid(self):
+        current_group_ids = posix.getresgid()
+        self.assertIsNone(posix.setresgid(*current_group_ids))
+        # -1 means don't change that value.
+        self.assertIsNone(posix.setresgid(-1, -1, -1))
 
-        def test_setresgid_exception(self):
-            # Don't do this test if someone is silly enough to run us as root.
-            current_group_ids = posix.getresgid()
-            if 0 not in current_group_ids:
-                new_group_ids = (current_group_ids[0]+1, -1, -1)
-                self.assertRaises(OSError, posix.setresgid, *new_group_ids)
+    @unittest.skipUnless(hasattr(posix, 'setresgid'),
+                         'test needs posix.setresgid()')
+    def test_setresgid_exception(self):
+        # Don't do this test if someone is silly enough to run us as root.
+        current_group_ids = posix.getresgid()
+        if 0 not in current_group_ids:
+            new_group_ids = (current_group_ids[0]+1, -1, -1)
+            self.assertRaises(OSError, posix.setresgid, *new_group_ids)
 
     @unittest.skipUnless(hasattr(posix, 'initgroups'),
                          "test needs os.initgroups()")
@@ -120,107 +128,118 @@
             else:
                 self.fail("Expected OSError to be raised by initgroups")
 
+    @unittest.skipUnless(hasattr(posix, 'statvfs'),
+                         'test needs posix.statvfs()')
     def test_statvfs(self):
-        if hasattr(posix, 'statvfs'):
-            self.assertTrue(posix.statvfs(os.curdir))
+        self.assertTrue(posix.statvfs(os.curdir))
 
+    @unittest.skipUnless(hasattr(posix, 'fstatvfs'),
+                         'test needs posix.fstatvfs()')
     def test_fstatvfs(self):
-        if hasattr(posix, 'fstatvfs'):
-            fp = open(test_support.TESTFN)
-            try:
-                self.assertTrue(posix.fstatvfs(fp.fileno()))
-            finally:
-                fp.close()
+        fp = open(test_support.TESTFN)
+        try:
+            self.assertTrue(posix.fstatvfs(fp.fileno()))
+        finally:
+            fp.close()
 
+    @unittest.skipUnless(hasattr(posix, 'ftruncate'),
+                         'test needs posix.ftruncate()')
     def test_ftruncate(self):
-        if hasattr(posix, 'ftruncate'):
-            fp = open(test_support.TESTFN, 'w+')
-            try:
-                # we need to have some data to truncate
-                fp.write('test')
-                fp.flush()
-                posix.ftruncate(fp.fileno(), 0)
-            finally:
-                fp.close()
+        fp = open(test_support.TESTFN, 'w+')
+        try:
+            # we need to have some data to truncate
+            fp.write('test')
+            fp.flush()
+            posix.ftruncate(fp.fileno(), 0)
+        finally:
+            fp.close()
 
+    @unittest.skipUnless(hasattr(posix, 'dup'),
+                         'test needs posix.dup()')
     def test_dup(self):
-        if hasattr(posix, 'dup'):
-            fp = open(test_support.TESTFN)
-            try:
-                fd = posix.dup(fp.fileno())
-                self.assertIsInstance(fd, int)
-                os.close(fd)
-            finally:
-                fp.close()
+        fp = open(test_support.TESTFN)
+        try:
+            fd = posix.dup(fp.fileno())
+            self.assertIsInstance(fd, int)
+            os.close(fd)
+        finally:
+            fp.close()
 
+    @unittest.skipUnless(hasattr(posix, 'confstr'),
+                         'test needs posix.confstr()')
     def test_confstr(self):
-        if hasattr(posix, 'confstr'):
-            self.assertRaises(ValueError, posix.confstr, "CS_garbage")
-            self.assertEqual(len(posix.confstr("CS_PATH")) > 0, True)
+        self.assertRaises(ValueError, posix.confstr, "CS_garbage")
+        self.assertEqual(len(posix.confstr("CS_PATH")) > 0, True)
 
+    @unittest.skipUnless(hasattr(posix, 'dup2'),
+                         'test needs posix.dup2()')
     def test_dup2(self):
-        if hasattr(posix, 'dup2'):
-            fp1 = open(test_support.TESTFN)
-            fp2 = open(test_support.TESTFN)
-            try:
-                posix.dup2(fp1.fileno(), fp2.fileno())
-            finally:
-                fp1.close()
-                fp2.close()
+        fp1 = open(test_support.TESTFN)
+        fp2 = open(test_support.TESTFN)
+        try:
+            posix.dup2(fp1.fileno(), fp2.fileno())
+        finally:
+            fp1.close()
+            fp2.close()
 
     def fdopen_helper(self, *args):
         fd = os.open(test_support.TESTFN, os.O_RDONLY)
         fp2 = posix.fdopen(fd, *args)
         fp2.close()
 
+    @unittest.skipUnless(hasattr(posix, 'fdopen'),
+                         'test needs posix.fdopen()')
     def test_fdopen(self):
-        if hasattr(posix, 'fdopen'):
-            self.fdopen_helper()
-            self.fdopen_helper('r')
-            self.fdopen_helper('r', 100)
+        self.fdopen_helper()
+        self.fdopen_helper('r')
+        self.fdopen_helper('r', 100)
 
+    @unittest.skipUnless(hasattr(posix, 'O_EXLOCK'),
+                         'test needs posix.O_EXLOCK')
     def test_osexlock(self):
-        if hasattr(posix, "O_EXLOCK"):
+        fd = os.open(test_support.TESTFN,
+                     os.O_WRONLY|os.O_EXLOCK|os.O_CREAT)
+        self.assertRaises(OSError, os.open, test_support.TESTFN,
+                          os.O_WRONLY|os.O_EXLOCK|os.O_NONBLOCK)
+        os.close(fd)
+
+        if hasattr(posix, "O_SHLOCK"):
             fd = os.open(test_support.TESTFN,
-                         os.O_WRONLY|os.O_EXLOCK|os.O_CREAT)
+                         os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
             self.assertRaises(OSError, os.open, test_support.TESTFN,
                               os.O_WRONLY|os.O_EXLOCK|os.O_NONBLOCK)
             os.close(fd)
 
-            if hasattr(posix, "O_SHLOCK"):
-                fd = os.open(test_support.TESTFN,
-                             os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
-                self.assertRaises(OSError, os.open, test_support.TESTFN,
-                                  os.O_WRONLY|os.O_EXLOCK|os.O_NONBLOCK)
-                os.close(fd)
-
+    @unittest.skipUnless(hasattr(posix, 'O_SHLOCK'),
+                         'test needs posix.O_SHLOCK')
     def test_osshlock(self):
-        if hasattr(posix, "O_SHLOCK"):
-            fd1 = os.open(test_support.TESTFN,
+        fd1 = os.open(test_support.TESTFN,
+                      os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
+        fd2 = os.open(test_support.TESTFN,
+                      os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
+        os.close(fd2)
+        os.close(fd1)
+
+        if hasattr(posix, "O_EXLOCK"):
+            fd = os.open(test_support.TESTFN,
                          os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
-            fd2 = os.open(test_support.TESTFN,
-                          os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
-            os.close(fd2)
-            os.close(fd1)
+            self.assertRaises(OSError, os.open, test_support.TESTFN,
+                              os.O_RDONLY|os.O_EXLOCK|os.O_NONBLOCK)
+            os.close(fd)
 
-            if hasattr(posix, "O_EXLOCK"):
-                fd = os.open(test_support.TESTFN,
-                             os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
-                self.assertRaises(OSError, os.open, test_support.TESTFN,
-                                  os.O_RDONLY|os.O_EXLOCK|os.O_NONBLOCK)
-                os.close(fd)
-
+    @unittest.skipUnless(hasattr(posix, 'fstat'),
+                         'test needs posix.fstat()')
     def test_fstat(self):
-        if hasattr(posix, 'fstat'):
-            fp = open(test_support.TESTFN)
-            try:
-                self.assertTrue(posix.fstat(fp.fileno()))
-            finally:
-                fp.close()
+        fp = open(test_support.TESTFN)
+        try:
+            self.assertTrue(posix.fstat(fp.fileno()))
+        finally:
+            fp.close()
 
+    @unittest.skipUnless(hasattr(posix, 'stat'),
+                         'test needs posix.stat()')
     def test_stat(self):
-        if hasattr(posix, 'stat'):
-            self.assertTrue(posix.stat(test_support.TESTFN))
+        self.assertTrue(posix.stat(test_support.TESTFN))
 
     def _test_all_chown_common(self, chown_func, first_param, stat_func):
         """Common code for chown, fchown and lchown tests."""
@@ -313,59 +332,62 @@
         self._test_all_chown_common(posix.lchown, test_support.TESTFN,
                                     getattr(posix, 'lstat', None))
 
+    @unittest.skipUnless(hasattr(posix, 'chdir'), 'test needs posix.chdir()')
     def test_chdir(self):
-        if hasattr(posix, 'chdir'):
-            posix.chdir(os.curdir)
-            self.assertRaises(OSError, posix.chdir, test_support.TESTFN)
+        posix.chdir(os.curdir)
+        self.assertRaises(OSError, posix.chdir, test_support.TESTFN)
 
+    @unittest.skipUnless(hasattr(posix, 'lsdir'), 'test needs posix.lsdir()')
     def test_lsdir(self):
-        if hasattr(posix, 'lsdir'):
-            self.assertIn(test_support.TESTFN, posix.lsdir(os.curdir))
+        self.assertIn(test_support.TESTFN, posix.lsdir(os.curdir))
 
+    @unittest.skipUnless(hasattr(posix, 'access'), 'test needs posix.access()')
     def test_access(self):
-        if hasattr(posix, 'access'):
-            self.assertTrue(posix.access(test_support.TESTFN, os.R_OK))
+        self.assertTrue(posix.access(test_support.TESTFN, os.R_OK))
 
+    @unittest.skipUnless(hasattr(posix, 'umask'), 'test needs posix.umask()')
     def test_umask(self):
-        if hasattr(posix, 'umask'):
-            old_mask = posix.umask(0)
-            self.assertIsInstance(old_mask, int)
-            posix.umask(old_mask)
+        old_mask = posix.umask(0)
+        self.assertIsInstance(old_mask, int)
+        posix.umask(old_mask)
 
+    @unittest.skipUnless(hasattr(posix, 'strerror'),
+                         'test needs posix.strerror()')
     def test_strerror(self):
-        if hasattr(posix, 'strerror'):
-            self.assertTrue(posix.strerror(0))
+        self.assertTrue(posix.strerror(0))
 
+    @unittest.skipUnless(hasattr(posix, 'pipe'), 'test needs posix.pipe()')
     def test_pipe(self):
-        if hasattr(posix, 'pipe'):
-            reader, writer = posix.pipe()
-            os.close(reader)
-            os.close(writer)
+        reader, writer = posix.pipe()
+        os.close(reader)
+        os.close(writer)
 
+    @unittest.skipUnless(hasattr(posix, 'tempnam'),
+                         'test needs posix.tempnam()')
     def test_tempnam(self):
-        if hasattr(posix, 'tempnam'):
-            with warnings.catch_warnings():
-                warnings.filterwarnings("ignore", "tempnam", DeprecationWarning)
-                self.assertTrue(posix.tempnam())
-                self.assertTrue(posix.tempnam(os.curdir))
-                self.assertTrue(posix.tempnam(os.curdir, 'blah'))
+        with warnings.catch_warnings():
+            warnings.filterwarnings("ignore", "tempnam", DeprecationWarning)
+            self.assertTrue(posix.tempnam())
+            self.assertTrue(posix.tempnam(os.curdir))
+            self.assertTrue(posix.tempnam(os.curdir, 'blah'))
 
+    @unittest.skipUnless(hasattr(posix, 'tmpfile'),
+                         'test needs posix.tmpfile()')
     def test_tmpfile(self):
-        if hasattr(posix, 'tmpfile'):
-            with warnings.catch_warnings():
-                warnings.filterwarnings("ignore", "tmpfile", DeprecationWarning)
-                fp = posix.tmpfile()
-                fp.close()
+        with warnings.catch_warnings():
+            warnings.filterwarnings("ignore", "tmpfile", DeprecationWarning)
+            fp = posix.tmpfile()
+            fp.close()
 
+    @unittest.skipUnless(hasattr(posix, 'utime'), 'test needs posix.utime()')
     def test_utime(self):
-        if hasattr(posix, 'utime'):
-            now = time.time()
-            posix.utime(test_support.TESTFN, None)
-            self.assertRaises(TypeError, posix.utime, test_support.TESTFN, (None, None))
-            self.assertRaises(TypeError, posix.utime, test_support.TESTFN, (now, None))
-            self.assertRaises(TypeError, posix.utime, test_support.TESTFN, (None, now))
-            posix.utime(test_support.TESTFN, (int(now), int(now)))
-            posix.utime(test_support.TESTFN, (now, now))
+        now = time.time()
+        posix.utime(test_support.TESTFN, None)
+        self.assertRaises(TypeError, posix.utime, test_support.TESTFN, (None, None))
+        self.assertRaises(TypeError, posix.utime, test_support.TESTFN, (now, None))
+        self.assertRaises(TypeError, posix.utime, test_support.TESTFN, (None, now))
+        posix.utime(test_support.TESTFN, (int(now), int(now)))
+        posix.utime(test_support.TESTFN, (now, now))
 
     def _test_chflags_regular_file(self, chflags_func, target_file):
         st = os.stat(target_file)
@@ -428,56 +450,57 @@
         finally:
             posix.lchflags(_DUMMY_SYMLINK, dummy_symlink_st.st_flags)
 
+    @unittest.skipUnless(hasattr(posix, 'getcwd'),
+                         'test needs posix.getcwd()')
     def test_getcwd_long_pathnames(self):
-        if hasattr(posix, 'getcwd'):
-            dirname = 'getcwd-test-directory-0123456789abcdef-01234567890abcdef'
-            curdir = os.getcwd()
-            base_path = os.path.abspath(test_support.TESTFN) + '.getcwd'
+        dirname = 'getcwd-test-directory-0123456789abcdef-01234567890abcdef'
+        curdir = os.getcwd()
+        base_path = os.path.abspath(test_support.TESTFN) + '.getcwd'
 
-            try:
-                os.mkdir(base_path)
-                os.chdir(base_path)
-            except:
-#               Just returning nothing instead of the SkipTest exception,
-#               because the test results in Error in that case.
-#               Is that ok?
-#                raise unittest.SkipTest, "cannot create directory for testing"
-                return
+        try:
+            os.mkdir(base_path)
+            os.chdir(base_path)
+        except:
+#           Just returning nothing instead of the SkipTest exception,
+#           because the test results in Error in that case.
+#           Is that ok?
+#            raise unittest.SkipTest, "cannot create directory for testing"
+            return
 
-            try:
-                def _create_and_do_getcwd(dirname, current_path_length = 0):
-                    try:
-                        os.mkdir(dirname)
-                    except:
-                        raise unittest.SkipTest, "mkdir cannot create directory sufficiently deep for getcwd test"
+        try:
+            def _create_and_do_getcwd(dirname, current_path_length = 0):
+                try:
+                    os.mkdir(dirname)
+                except:
+                    raise unittest.SkipTest, "mkdir cannot create directory sufficiently deep for getcwd test"
 
-                    os.chdir(dirname)
-                    try:
-                        os.getcwd()
-                        if current_path_length < 4099:
-                            _create_and_do_getcwd(dirname, current_path_length + len(dirname) + 1)
-                    except OSError as e:
-                        expected_errno = errno.ENAMETOOLONG
-                        # The following platforms have quirky getcwd()
-                        # behaviour -- see issue 9185 and 15765 for
-                        # more information.
-                        quirky_platform = (
-                            'sunos' in sys.platform or
-                            'netbsd' in sys.platform or
-                            'openbsd' in sys.platform
-                        )
-                        if quirky_platform:
-                            expected_errno = errno.ERANGE
-                        self.assertEqual(e.errno, expected_errno)
-                    finally:
-                        os.chdir('..')
-                        os.rmdir(dirname)
+                os.chdir(dirname)
+                try:
+                    os.getcwd()
+                    if current_path_length < 4099:
+                        _create_and_do_getcwd(dirname, current_path_length + len(dirname) + 1)
+                except OSError as e:
+                    expected_errno = errno.ENAMETOOLONG
+                    # The following platforms have quirky getcwd()
+                    # behaviour -- see issue 9185 and 15765 for
+                    # more information.
+                    quirky_platform = (
+                        'sunos' in sys.platform or
+                        'netbsd' in sys.platform or
+                        'openbsd' in sys.platform
+                    )
+                    if quirky_platform:
+                        expected_errno = errno.ERANGE
+                    self.assertEqual(e.errno, expected_errno)
+                finally:
+                    os.chdir('..')
+                    os.rmdir(dirname)
 
-                _create_and_do_getcwd(dirname)
+            _create_and_do_getcwd(dirname)
 
-            finally:
-                os.chdir(curdir)
-                shutil.rmtree(base_path)
+        finally:
+            os.chdir(curdir)
+            shutil.rmtree(base_path)
 
     @unittest.skipUnless(hasattr(os, 'getegid'), "test needs os.getegid()")
     def test_getgroups(self):
@@ -522,7 +545,7 @@
             posix.initgroups(name, self.saved_groups[0])
 
     @unittest.skipUnless(hasattr(posix, 'initgroups'),
-                         "test needs posix.initgroups()")
+                         'test needs posix.initgroups()')
     def test_initgroups(self):
         # find missing group
 
@@ -532,7 +555,7 @@
         self.assertIn(g, posix.getgroups())
 
     @unittest.skipUnless(hasattr(posix, 'setgroups'),
-                         "test needs posix.setgroups()")
+                         'test needs posix.setgroups()')
     def test_setgroups(self):
         for groups in [[0], range(16)]:
             posix.setgroups(groups)
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index 8db26ed..9db7394 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -561,10 +561,10 @@
         s = None
         self.assertRaises(ReferenceError, str, p)
 
-    # C API test only available in a debug build
-    if hasattr(set, "test_c_api"):
-        def test_c_api(self):
-            self.assertEqual(set().test_c_api(), True)
+    @unittest.skipUnless(hasattr(set, "test_c_api"),
+                         'C API test only available in a debug build')
+    def test_c_api(self):
+        self.assertEqual(set().test_c_api(), True)
 
 class SetSubclass(set):
     pass
diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
index 9bdb724..8f1abd8 100644
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -78,33 +78,34 @@
         filename = tempfile.mktemp()
         self.assertRaises(OSError, shutil.rmtree, filename)
 
-    # See bug #1071513 for why we don't run this on cygwin
-    # and bug #1076467 for why we don't run this as root.
-    if (hasattr(os, 'chmod') and sys.platform[:6] != 'cygwin'
-        and not (hasattr(os, 'geteuid') and os.geteuid() == 0)):
-        def test_on_error(self):
-            self.errorState = 0
-            os.mkdir(TESTFN)
-            self.childpath = os.path.join(TESTFN, 'a')
-            f = open(self.childpath, 'w')
-            f.close()
-            old_dir_mode = os.stat(TESTFN).st_mode
-            old_child_mode = os.stat(self.childpath).st_mode
-            # Make unwritable.
-            os.chmod(self.childpath, stat.S_IREAD)
-            os.chmod(TESTFN, stat.S_IREAD)
+    @unittest.skipUnless(hasattr(os, 'chmod'), 'requires os.chmod()')
+    @unittest.skipIf(sys.platform[:6] == 'cygwin',
+                     "This test can't be run on Cygwin (issue #1071513).")
+    @unittest.skipIf(hasattr(os, 'geteuid') and os.geteuid() == 0,
+                     "This test can't be run reliably as root (issue #1076467).")
+    def test_on_error(self):
+        self.errorState = 0
+        os.mkdir(TESTFN)
+        self.childpath = os.path.join(TESTFN, 'a')
+        f = open(self.childpath, 'w')
+        f.close()
+        old_dir_mode = os.stat(TESTFN).st_mode
+        old_child_mode = os.stat(self.childpath).st_mode
+        # Make unwritable.
+        os.chmod(self.childpath, stat.S_IREAD)
+        os.chmod(TESTFN, stat.S_IREAD)
 
-            shutil.rmtree(TESTFN, onerror=self.check_args_to_onerror)
-            # Test whether onerror has actually been called.
-            self.assertEqual(self.errorState, 2,
-                             "Expected call to onerror function did not happen.")
+        shutil.rmtree(TESTFN, onerror=self.check_args_to_onerror)
+        # Test whether onerror has actually been called.
+        self.assertEqual(self.errorState, 2,
+                            "Expected call to onerror function did not happen.")
 
-            # Make writable again.
-            os.chmod(TESTFN, old_dir_mode)
-            os.chmod(self.childpath, old_child_mode)
+        # Make writable again.
+        os.chmod(TESTFN, old_dir_mode)
+        os.chmod(self.childpath, old_child_mode)
 
-            # Clean up.
-            shutil.rmtree(TESTFN)
+        # Clean up.
+        shutil.rmtree(TESTFN)
 
     def check_args_to_onerror(self, func, arg, exc):
         # test_rmtree_errors deliberately runs rmtree
@@ -308,37 +309,38 @@
             finally:
                 shutil.rmtree(TESTFN, ignore_errors=True)
 
-    if hasattr(os, "mkfifo"):
-        # Issue #3002: copyfile and copytree block indefinitely on named pipes
-        def test_copyfile_named_pipe(self):
-            os.mkfifo(TESTFN)
-            try:
-                self.assertRaises(shutil.SpecialFileError,
-                                  shutil.copyfile, TESTFN, TESTFN2)
-                self.assertRaises(shutil.SpecialFileError,
-                                  shutil.copyfile, __file__, TESTFN)
-            finally:
-                os.remove(TESTFN)
+    # Issue #3002: copyfile and copytree block indefinitely on named pipes
+    @unittest.skipUnless(hasattr(os, "mkfifo"), 'requires os.mkfifo()')
+    def test_copyfile_named_pipe(self):
+        os.mkfifo(TESTFN)
+        try:
+            self.assertRaises(shutil.SpecialFileError,
+                              shutil.copyfile, TESTFN, TESTFN2)
+            self.assertRaises(shutil.SpecialFileError,
+                              shutil.copyfile, __file__, TESTFN)
+        finally:
+            os.remove(TESTFN)
 
-        def test_copytree_named_pipe(self):
-            os.mkdir(TESTFN)
+    @unittest.skipUnless(hasattr(os, "mkfifo"), 'requires os.mkfifo()')
+    def test_copytree_named_pipe(self):
+        os.mkdir(TESTFN)
+        try:
+            subdir = os.path.join(TESTFN, "subdir")
+            os.mkdir(subdir)
+            pipe = os.path.join(subdir, "mypipe")
+            os.mkfifo(pipe)
             try:
-                subdir = os.path.join(TESTFN, "subdir")
-                os.mkdir(subdir)
-                pipe = os.path.join(subdir, "mypipe")
-                os.mkfifo(pipe)
-                try:
-                    shutil.copytree(TESTFN, TESTFN2)
-                except shutil.Error as e:
-                    errors = e.args[0]
-                    self.assertEqual(len(errors), 1)
-                    src, dst, error_msg = errors[0]
-                    self.assertEqual("`%s` is a named pipe" % pipe, error_msg)
-                else:
-                    self.fail("shutil.Error should have been raised")
-            finally:
-                shutil.rmtree(TESTFN, ignore_errors=True)
-                shutil.rmtree(TESTFN2, ignore_errors=True)
+                shutil.copytree(TESTFN, TESTFN2)
+            except shutil.Error as e:
+                errors = e.args[0]
+                self.assertEqual(len(errors), 1)
+                src, dst, error_msg = errors[0]
+                self.assertEqual("`%s` is a named pipe" % pipe, error_msg)
+            else:
+                self.fail("shutil.Error should have been raised")
+        finally:
+            shutil.rmtree(TESTFN, ignore_errors=True)
+            shutil.rmtree(TESTFN2, ignore_errors=True)
 
     @unittest.skipUnless(hasattr(os, 'chflags') and
                          hasattr(errno, 'EOPNOTSUPP') and
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index aef9b1a..53c8b2f 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -343,16 +343,17 @@
         if not fqhn in all_host_names:
             self.fail("Error testing host resolution mechanisms. (fqdn: %s, all: %s)" % (fqhn, repr(all_host_names)))
 
+    @unittest.skipUnless(hasattr(sys, 'getrefcount'),
+                         'test needs sys.getrefcount()')
     def testRefCountGetNameInfo(self):
         # Testing reference count for getnameinfo
-        if hasattr(sys, "getrefcount"):
-            try:
-                # On some versions, this loses a reference
-                orig = sys.getrefcount(__name__)
-                socket.getnameinfo(__name__,0)
-            except TypeError:
-                self.assertEqual(sys.getrefcount(__name__), orig,
-                                 "socket.getnameinfo loses a reference")
+        try:
+            # On some versions, this loses a reference
+            orig = sys.getrefcount(__name__)
+            socket.getnameinfo(__name__,0)
+        except TypeError:
+            self.assertEqual(sys.getrefcount(__name__), orig,
+                             "socket.getnameinfo loses a reference")
 
     def testInterpreterCrash(self):
         # Making sure getnameinfo doesn't crash the interpreter
@@ -459,17 +460,17 @@
         # Check that setting it to an invalid type raises TypeError
         self.assertRaises(TypeError, socket.setdefaulttimeout, "spam")
 
+    @unittest.skipUnless(hasattr(socket, 'inet_aton'),
+                         'test needs socket.inet_aton()')
     def testIPv4_inet_aton_fourbytes(self):
-        if not hasattr(socket, 'inet_aton'):
-            return  # No inet_aton, nothing to check
         # Test that issue1008086 and issue767150 are fixed.
         # It must return 4 bytes.
         self.assertEqual('\x00'*4, socket.inet_aton('0.0.0.0'))
         self.assertEqual('\xff'*4, socket.inet_aton('255.255.255.255'))
 
+    @unittest.skipUnless(hasattr(socket, 'inet_pton'),
+                         'test needs socket.inet_pton()')
     def testIPv4toString(self):
-        if not hasattr(socket, 'inet_pton'):
-            return # No inet_pton() on this platform
         from socket import inet_aton as f, inet_pton, AF_INET
         g = lambda a: inet_pton(AF_INET, a)
 
@@ -484,9 +485,9 @@
         self.assertEqual('\xaa\xaa\xaa\xaa', g('170.170.170.170'))
         self.assertEqual('\xff\xff\xff\xff', g('255.255.255.255'))
 
+    @unittest.skipUnless(hasattr(socket, 'inet_pton'),
+                         'test needs socket.inet_pton()')
     def testIPv6toString(self):
-        if not hasattr(socket, 'inet_pton'):
-            return # No inet_pton() on this platform
         try:
             from socket import inet_pton, AF_INET6, has_ipv6
             if not has_ipv6:
@@ -503,9 +504,9 @@
             f('45ef:76cb:1a:56ef:afeb:bac:1924:aeae')
         )
 
+    @unittest.skipUnless(hasattr(socket, 'inet_ntop'),
+                         'test needs socket.inet_ntop()')
     def testStringToIPv4(self):
-        if not hasattr(socket, 'inet_ntop'):
-            return # No inet_ntop() on this platform
         from socket import inet_ntoa as f, inet_ntop, AF_INET
         g = lambda a: inet_ntop(AF_INET, a)
 
@@ -518,9 +519,9 @@
         self.assertEqual('170.85.170.85', g('\xaa\x55\xaa\x55'))
         self.assertEqual('255.255.255.255', g('\xff\xff\xff\xff'))
 
+    @unittest.skipUnless(hasattr(socket, 'inet_ntop'),
+                         'test needs socket.inet_ntop()')
     def testStringToIPv6(self):
-        if not hasattr(socket, 'inet_ntop'):
-            return # No inet_ntop() on this platform
         try:
             from socket import inet_ntop, AF_INET6, has_ipv6
             if not has_ipv6:
@@ -871,6 +872,8 @@
         self.cli.connect((HOST, self.port))
         time.sleep(1.0)
 
+@unittest.skipUnless(hasattr(socket, 'socketpair'),
+                     'test needs socket.socketpair()')
 @unittest.skipUnless(thread, 'Threading required for this test.')
 class BasicSocketPairTest(SocketPairTest):
 
@@ -1456,12 +1459,12 @@
         if not ok:
             self.fail("accept() returned success when we did not expect it")
 
+    @unittest.skipUnless(hasattr(signal, 'alarm'),
+                         'test needs signal.alarm()')
     def testInterruptedTimeout(self):
         # XXX I don't know how to do this test on MSWindows or any other
         # plaform that doesn't support signal.alarm() or os.kill(), though
         # the bug should have existed on all platforms.
-        if not hasattr(signal, "alarm"):
-            return                  # can only test on *nix
         self.serv.settimeout(5.0)   # must be longer than alarm
         class Alarm(Exception):
             pass
@@ -1521,6 +1524,7 @@
         self.assertTrue(issubclass(socket.gaierror, socket.error))
         self.assertTrue(issubclass(socket.timeout, socket.error))
 
+@unittest.skipUnless(sys.platform == 'linux', 'Linux specific test')
 class TestLinuxAbstractNamespace(unittest.TestCase):
 
     UNIX_PATH_MAX = 108
@@ -1635,11 +1639,11 @@
         for line in f:
             if line.startswith("tipc "):
                 return True
-    if test_support.verbose:
-        print "TIPC module is not loaded, please 'sudo modprobe tipc'"
     return False
 
-class TIPCTest (unittest.TestCase):
+@unittest.skipUnless(isTipcAvailable(),
+                     "TIPC module is not loaded, please 'sudo modprobe tipc'")
+class TIPCTest(unittest.TestCase):
     def testRDM(self):
         srv = socket.socket(socket.AF_TIPC, socket.SOCK_RDM)
         cli = socket.socket(socket.AF_TIPC, socket.SOCK_RDM)
@@ -1659,7 +1663,9 @@
         self.assertEqual(msg, MSG)
 
 
-class TIPCThreadableTest (unittest.TestCase, ThreadableTest):
+@unittest.skipUnless(isTipcAvailable(),
+                     "TIPC module is not loaded, please 'sudo modprobe tipc'")
+class TIPCThreadableTest(unittest.TestCase, ThreadableTest):
     def __init__(self, methodName = 'runTest'):
         unittest.TestCase.__init__(self, methodName = methodName)
         ThreadableTest.__init__(self)
@@ -1712,13 +1718,9 @@
         NetworkConnectionAttributesTest,
         NetworkConnectionBehaviourTest,
     ])
-    if hasattr(socket, "socketpair"):
-        tests.append(BasicSocketPairTest)
-    if sys.platform == 'linux2':
-        tests.append(TestLinuxAbstractNamespace)
-    if isTipcAvailable():
-        tests.append(TIPCTest)
-        tests.append(TIPCThreadableTest)
+    tests.append(BasicSocketPairTest)
+    tests.append(TestLinuxAbstractNamespace)
+    tests.extend([TIPCTest, TIPCThreadableTest])
 
     thread_info = test_support.threading_setup()
     test_support.run_unittest(*tests)
diff --git a/Lib/test/test_socketserver.py b/Lib/test/test_socketserver.py
index 0dbb8e2..83f5e3f 100644
--- a/Lib/test/test_socketserver.py
+++ b/Lib/test/test_socketserver.py
@@ -27,7 +27,10 @@
 HOST = test.test_support.HOST
 
 HAVE_UNIX_SOCKETS = hasattr(socket, "AF_UNIX")
+requires_unix_sockets = unittest.skipUnless(HAVE_UNIX_SOCKETS,
+                                            'requires Unix sockets')
 HAVE_FORKING = hasattr(os, "fork") and os.name != "os2"
+requires_forking = unittest.skipUnless(HAVE_FORKING, 'requires forking')
 
 def signal_alarm(n):
     """Call signal.alarm when it exists (i.e. not on Windows)."""
@@ -188,31 +191,33 @@
                         SocketServer.StreamRequestHandler,
                         self.stream_examine)
 
-    if HAVE_FORKING:
-        def test_ForkingTCPServer(self):
-            with simple_subprocess(self):
-                self.run_server(SocketServer.ForkingTCPServer,
-                                SocketServer.StreamRequestHandler,
-                                self.stream_examine)
-
-    if HAVE_UNIX_SOCKETS:
-        def test_UnixStreamServer(self):
-            self.run_server(SocketServer.UnixStreamServer,
+    @requires_forking
+    def test_ForkingTCPServer(self):
+        with simple_subprocess(self):
+            self.run_server(SocketServer.ForkingTCPServer,
                             SocketServer.StreamRequestHandler,
                             self.stream_examine)
 
-        def test_ThreadingUnixStreamServer(self):
-            self.run_server(SocketServer.ThreadingUnixStreamServer,
+    @requires_unix_sockets
+    def test_UnixStreamServer(self):
+        self.run_server(SocketServer.UnixStreamServer,
+                        SocketServer.StreamRequestHandler,
+                        self.stream_examine)
+
+    @requires_unix_sockets
+    def test_ThreadingUnixStreamServer(self):
+        self.run_server(SocketServer.ThreadingUnixStreamServer,
+                        SocketServer.StreamRequestHandler,
+                        self.stream_examine)
+
+    @requires_unix_sockets
+    @requires_forking
+    def test_ForkingUnixStreamServer(self):
+        with simple_subprocess(self):
+            self.run_server(ForkingUnixStreamServer,
                             SocketServer.StreamRequestHandler,
                             self.stream_examine)
 
-        if HAVE_FORKING:
-            def test_ForkingUnixStreamServer(self):
-                with simple_subprocess(self):
-                    self.run_server(ForkingUnixStreamServer,
-                                    SocketServer.StreamRequestHandler,
-                                    self.stream_examine)
-
     def test_UDPServer(self):
         self.run_server(SocketServer.UDPServer,
                         SocketServer.DatagramRequestHandler,
@@ -223,12 +228,12 @@
                         SocketServer.DatagramRequestHandler,
                         self.dgram_examine)
 
-    if HAVE_FORKING:
-        def test_ForkingUDPServer(self):
-            with simple_subprocess(self):
-                self.run_server(SocketServer.ForkingUDPServer,
-                                SocketServer.DatagramRequestHandler,
-                                self.dgram_examine)
+    @requires_forking
+    def test_ForkingUDPServer(self):
+        with simple_subprocess(self):
+            self.run_server(SocketServer.ForkingUDPServer,
+                            SocketServer.DatagramRequestHandler,
+                            self.dgram_examine)
 
     @contextlib.contextmanager
     def mocked_select_module(self):
@@ -265,22 +270,24 @@
     # Alas, on Linux (at least) recvfrom() doesn't return a meaningful
     # client address so this cannot work:
 
-    # if HAVE_UNIX_SOCKETS:
-    #     def test_UnixDatagramServer(self):
-    #         self.run_server(SocketServer.UnixDatagramServer,
-    #                         SocketServer.DatagramRequestHandler,
-    #                         self.dgram_examine)
+    # @requires_unix_sockets
+    # def test_UnixDatagramServer(self):
+    #     self.run_server(SocketServer.UnixDatagramServer,
+    #                     SocketServer.DatagramRequestHandler,
+    #                     self.dgram_examine)
     #
-    #     def test_ThreadingUnixDatagramServer(self):
-    #         self.run_server(SocketServer.ThreadingUnixDatagramServer,
-    #                         SocketServer.DatagramRequestHandler,
-    #                         self.dgram_examine)
+    # @requires_unix_sockets
+    # def test_ThreadingUnixDatagramServer(self):
+    #     self.run_server(SocketServer.ThreadingUnixDatagramServer,
+    #                     SocketServer.DatagramRequestHandler,
+    #                     self.dgram_examine)
     #
-    #     if HAVE_FORKING:
-    #         def test_ForkingUnixDatagramServer(self):
-    #             self.run_server(SocketServer.ForkingUnixDatagramServer,
-    #                             SocketServer.DatagramRequestHandler,
-    #                             self.dgram_examine)
+    # @requires_unix_sockets
+    # @requires_forking
+    # def test_ForkingUnixDatagramServer(self):
+    #     self.run_server(SocketServer.ForkingUnixDatagramServer,
+    #                     SocketServer.DatagramRequestHandler,
+    #                     self.dgram_examine)
 
     @reap_threads
     def test_shutdown(self):
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index fbea655..fcca676 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -266,15 +266,16 @@
         #  still has 5 elements
         maj, min, buildno, plat, csd = sys.getwindowsversion()
 
+    @unittest.skipUnless(hasattr(sys, "setdlopenflags"),
+                         'test needs sys.setdlopenflags()')
     def test_dlopenflags(self):
-        if hasattr(sys, "setdlopenflags"):
-            self.assertTrue(hasattr(sys, "getdlopenflags"))
-            self.assertRaises(TypeError, sys.getdlopenflags, 42)
-            oldflags = sys.getdlopenflags()
-            self.assertRaises(TypeError, sys.setdlopenflags)
-            sys.setdlopenflags(oldflags+1)
-            self.assertEqual(sys.getdlopenflags(), oldflags+1)
-            sys.setdlopenflags(oldflags)
+        self.assertTrue(hasattr(sys, "getdlopenflags"))
+        self.assertRaises(TypeError, sys.getdlopenflags, 42)
+        oldflags = sys.getdlopenflags()
+        self.assertRaises(TypeError, sys.setdlopenflags)
+        sys.setdlopenflags(oldflags+1)
+        self.assertEqual(sys.getdlopenflags(), oldflags+1)
+        sys.setdlopenflags(oldflags)
 
     def test_refcount(self):
         # n here must be a global in order for this test to pass while
diff --git a/Lib/test/test_warnings.py b/Lib/test/test_warnings.py
index e502ed8..e4850a4 100644
--- a/Lib/test/test_warnings.py
+++ b/Lib/test/test_warnings.py
@@ -259,11 +259,10 @@
         finally:
             warning_tests.__file__ = filename
 
+    @unittest.skipUnless(hasattr(sys, 'argv'), 'test needs sys.argv')
     def test_missing_filename_main_with_argv(self):
         # If __file__ is not specified and the caller is __main__ and sys.argv
         # exists, then use sys.argv[0] as the file.
-        if not hasattr(sys, 'argv'):
-            return
         filename = warning_tests.__file__
         module_name = warning_tests.__name__
         try:
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index f3dffd6..fb62081 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -12,6 +12,13 @@
 
 zlib = import_module('zlib')
 
+requires_Compress_copy = unittest.skipUnless(
+        hasattr(zlib.compressobj(), "copy"),
+        'requires Compress.copy()')
+requires_Decompress_copy = unittest.skipUnless(
+        hasattr(zlib.decompressobj(), "copy"),
+        'requires Decompress.copy()')
+
 
 class ChecksumTestCase(unittest.TestCase):
     # checksum test cases
@@ -339,39 +346,39 @@
                                         "mode=%i, level=%i") % (sync, level))
                 del obj
 
+    @unittest.skipUnless(hasattr(zlib, 'Z_SYNC_FLUSH'),
+                         'requires zlib.Z_SYNC_FLUSH')
     def test_odd_flush(self):
         # Test for odd flushing bugs noted in 2.0, and hopefully fixed in 2.1
         import random
+        # Testing on 17K of "random" data
 
-        if hasattr(zlib, 'Z_SYNC_FLUSH'):
-            # Testing on 17K of "random" data
+        # Create compressor and decompressor objects
+        co = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
+        dco = zlib.decompressobj()
 
-            # Create compressor and decompressor objects
-            co = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
-            dco = zlib.decompressobj()
-
-            # Try 17K of data
-            # generate random data stream
+        # Try 17K of data
+        # generate random data stream
+        try:
+            # In 2.3 and later, WichmannHill is the RNG of the bug report
+            gen = random.WichmannHill()
+        except AttributeError:
             try:
-                # In 2.3 and later, WichmannHill is the RNG of the bug report
-                gen = random.WichmannHill()
+                # 2.2 called it Random
+                gen = random.Random()
             except AttributeError:
-                try:
-                    # 2.2 called it Random
-                    gen = random.Random()
-                except AttributeError:
-                    # others might simply have a single RNG
-                    gen = random
-            gen.seed(1)
-            data = genblock(1, 17 * 1024, generator=gen)
+                # others might simply have a single RNG
+                gen = random
+        gen.seed(1)
+        data = genblock(1, 17 * 1024, generator=gen)
 
-            # compress, sync-flush, and decompress
-            first = co.compress(data)
-            second = co.flush(zlib.Z_SYNC_FLUSH)
-            expanded = dco.decompress(first + second)
+        # compress, sync-flush, and decompress
+        first = co.compress(data)
+        second = co.flush(zlib.Z_SYNC_FLUSH)
+        expanded = dco.decompress(first + second)
 
-            # if decompressed data is different from the input data, choke.
-            self.assertEqual(expanded, data, "17K random source doesn't match")
+        # if decompressed data is different from the input data, choke.
+        self.assertEqual(expanded, data, "17K random source doesn't match")
 
     def test_empty_flush(self):
         # Test that calling .flush() on unused objects works.
@@ -408,35 +415,36 @@
         data = zlib.compress(input2)
         self.assertEqual(dco.flush(), input1[1:])
 
-    if hasattr(zlib.compressobj(), "copy"):
-        def test_compresscopy(self):
-            # Test copying a compression object
-            data0 = HAMLET_SCENE
-            data1 = HAMLET_SCENE.swapcase()
-            c0 = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
-            bufs0 = []
-            bufs0.append(c0.compress(data0))
+    @requires_Compress_copy
+    def test_compresscopy(self):
+        # Test copying a compression object
+        data0 = HAMLET_SCENE
+        data1 = HAMLET_SCENE.swapcase()
+        c0 = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
+        bufs0 = []
+        bufs0.append(c0.compress(data0))
 
-            c1 = c0.copy()
-            bufs1 = bufs0[:]
+        c1 = c0.copy()
+        bufs1 = bufs0[:]
 
-            bufs0.append(c0.compress(data0))
-            bufs0.append(c0.flush())
-            s0 = ''.join(bufs0)
+        bufs0.append(c0.compress(data0))
+        bufs0.append(c0.flush())
+        s0 = ''.join(bufs0)
 
-            bufs1.append(c1.compress(data1))
-            bufs1.append(c1.flush())
-            s1 = ''.join(bufs1)
+        bufs1.append(c1.compress(data1))
+        bufs1.append(c1.flush())
+        s1 = ''.join(bufs1)
 
-            self.assertEqual(zlib.decompress(s0),data0+data0)
-            self.assertEqual(zlib.decompress(s1),data0+data1)
+        self.assertEqual(zlib.decompress(s0),data0+data0)
+        self.assertEqual(zlib.decompress(s1),data0+data1)
 
-        def test_badcompresscopy(self):
-            # Test copying a compression object in an inconsistent state
-            c = zlib.compressobj()
-            c.compress(HAMLET_SCENE)
-            c.flush()
-            self.assertRaises(ValueError, c.copy)
+    @requires_Compress_copy
+    def test_badcompresscopy(self):
+        # Test copying a compression object in an inconsistent state
+        c = zlib.compressobj()
+        c.compress(HAMLET_SCENE)
+        c.flush()
+        self.assertRaises(ValueError, c.copy)
 
     def test_decompress_unused_data(self):
         # Repeated calls to decompress() after EOF should accumulate data in
@@ -463,35 +471,36 @@
                 self.assertEqual(dco.unconsumed_tail, b'')
                 self.assertEqual(dco.unused_data, remainder)
 
-    if hasattr(zlib.decompressobj(), "copy"):
-        def test_decompresscopy(self):
-            # Test copying a decompression object
-            data = HAMLET_SCENE
-            comp = zlib.compress(data)
+    @requires_Decompress_copy
+    def test_decompresscopy(self):
+        # Test copying a decompression object
+        data = HAMLET_SCENE
+        comp = zlib.compress(data)
 
-            d0 = zlib.decompressobj()
-            bufs0 = []
-            bufs0.append(d0.decompress(comp[:32]))
+        d0 = zlib.decompressobj()
+        bufs0 = []
+        bufs0.append(d0.decompress(comp[:32]))
 
-            d1 = d0.copy()
-            bufs1 = bufs0[:]
+        d1 = d0.copy()
+        bufs1 = bufs0[:]
 
-            bufs0.append(d0.decompress(comp[32:]))
-            s0 = ''.join(bufs0)
+        bufs0.append(d0.decompress(comp[32:]))
+        s0 = ''.join(bufs0)
 
-            bufs1.append(d1.decompress(comp[32:]))
-            s1 = ''.join(bufs1)
+        bufs1.append(d1.decompress(comp[32:]))
+        s1 = ''.join(bufs1)
 
-            self.assertEqual(s0,s1)
-            self.assertEqual(s0,data)
+        self.assertEqual(s0,s1)
+        self.assertEqual(s0,data)
 
-        def test_baddecompresscopy(self):
-            # Test copying a compression object in an inconsistent state
-            data = zlib.compress(HAMLET_SCENE)
-            d = zlib.decompressobj()
-            d.decompress(data)
-            d.flush()
-            self.assertRaises(ValueError, d.copy)
+    @requires_Decompress_copy
+    def test_baddecompresscopy(self):
+        # Test copying a compression object in an inconsistent state
+        data = zlib.compress(HAMLET_SCENE)
+        d = zlib.decompressobj()
+        d.decompress(data)
+        d.flush()
+        self.assertRaises(ValueError, d.copy)
 
     # Memory use of the following functions takes into account overallocation
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 6f3b33a..12bfafb 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -23,6 +23,8 @@
 Tests
 -----
 
+- Issue #18702: All skipped tests now reported as skipped.
+
 - Issue #19085: Added basic tests for all tkinter widget options.