Issue 19572: More silently skipped tests explicitly skipped.

34 files changed, 137 insertions, 146 deletions

diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py
index bd26e3d..e439194 100644
--- a/Lib/test/_test_multiprocessing.py
+++ b/Lib/test/_test_multiprocessing.py
@@ -198,7 +198,7 @@ class _TestProcess(BaseTestCase):
 
     def test_current(self):
         if self.TYPE == 'threads':
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
 
         current = self.current_process()
         authkey = current.authkey
@@ -212,7 +212,7 @@ class _TestProcess(BaseTestCase):
 
     def test_daemon_argument(self):
         if self.TYPE == "threads":
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
 
         # By default uses the current process's daemon flag.
         proc0 = self.Process(target=self._test)
@@ -277,7 +277,7 @@ class _TestProcess(BaseTestCase):
 
     def test_terminate(self):
         if self.TYPE == 'threads':
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
 
         p = self.Process(target=self._test_terminate)
         p.daemon = True
@@ -385,7 +385,7 @@ class _TestProcess(BaseTestCase):
 
     def test_sentinel(self):
         if self.TYPE == "threads":
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
         event = self.Event()
         p = self.Process(target=self._test_sentinel, args=(event,))
         with self.assertRaises(ValueError):
@@ -441,7 +441,7 @@ class _TestSubclassingProcess(BaseTestCase):
     def test_stderr_flush(self):
         # sys.stderr is flushed at process shutdown (issue #13812)
         if self.TYPE == "threads":
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
 
         testfn = test.support.TESTFN
         self.addCleanup(test.support.unlink, testfn)
@@ -469,7 +469,7 @@ class _TestSubclassingProcess(BaseTestCase):
     def test_sys_exit(self):
         # See Issue 13854
         if self.TYPE == 'threads':
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
 
         testfn = test.support.TESTFN
         self.addCleanup(test.support.unlink, testfn)
@@ -678,7 +678,7 @@ class _TestQueue(BaseTestCase):
         try:
             self.assertEqual(q.qsize(), 0)
         except NotImplementedError:
-            return
+            self.skipTest('qsize method not implemented')
         q.put(1)
         self.assertEqual(q.qsize(), 1)
         q.put(5)
@@ -786,7 +786,7 @@ class _TestSemaphore(BaseTestCase):
 
     def test_timeout(self):
         if self.TYPE != 'processes':
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
 
         sem = self.Semaphore(0)
         acquire = TimingWrapper(sem.acquire)
@@ -1406,7 +1406,7 @@ class _TestBarrier(BaseTestCase):
 
     def test_thousand(self):
         if self.TYPE == 'manager':
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
         passes = 1000
         lock = self.Lock()
         conn, child_conn = self.Pipe(False)
@@ -1701,7 +1701,7 @@ class _TestPool(BaseTestCase):
     def test_map_unplicklable(self):
         # Issue #19425 -- failure to pickle should not cause a hang
         if self.TYPE == 'threads':
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
         class A(object):
             def __reduce__(self):
                 raise RuntimeError('cannot pickle')
@@ -2224,7 +2224,7 @@ class _TestConnection(BaseTestCase):
 
     def test_sendbytes(self):
         if self.TYPE != 'processes':
-            return
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
 
         msg = latin('abcdefghijklmnopqrstuvwxyz')
         a, b = self.Pipe()
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index b67d28c..3f3c60a 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -2029,6 +2029,7 @@ class TestDateTime(TestDate):
 class TestSubclassDateTime(TestDateTime):
     theclass = SubclassDatetime
     # Override tests not designed for subclass
+    @unittest.skip('not appropriate for subclasses')
     def test_roundtrip(self):
         pass
 
diff --git a/Lib/test/multibytecodec_support.py b/Lib/test/multibytecodec_support.py
index dcaae7b..b93cc83 100644
--- a/Lib/test/multibytecodec_support.py
+++ b/Lib/test/multibytecodec_support.py
@@ -73,7 +73,7 @@ class TestBase:
 
     def test_xmlcharrefreplace(self):
         if self.has_iso10646:
-            return
+            self.skipTest('encoding contains full ISO 10646 map')
 
         s = "\u0b13\u0b23\u0b60 nd eggs"
         self.assertEqual(
@@ -83,7 +83,7 @@ class TestBase:
 
     def test_customreplace_encode(self):
         if self.has_iso10646:
-            return
+            self.skipTest('encoding contains full ISO 10646 map')
 
         from html.entities import codepoint2name
 
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index 30784d4..ef995e2 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -676,10 +676,10 @@ class BaseTest:
         self.checkraises(TypeError, 'hello', 'replace', 42, 'h')
         self.checkraises(TypeError, 'hello', 'replace', 'h', 42)
 
+    @unittest.skipIf(sys.maxsize > (1 << 32) or struct.calcsize('P') != 4,
+                     'only applies to 32-bit platforms')
     def test_replace_overflow(self):
         # Check for overflow checking on 32 bit machines
-        if sys.maxsize != 2147483647 or struct.calcsize("P") > 4:
-            return
         A2_16 = "A" * (2**16)
         self.checkraises(OverflowError, A2_16, "replace", "", A2_16)
         self.checkraises(OverflowError, A2_16, "replace", "A", A2_16)
diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index 409d586..9821a84 100755
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -946,7 +946,7 @@ class BaseTest:
         try:
             import gc
         except ImportError:
-            return
+            self.skipTest('gc module not available')
         a = array.array(self.typecode)
         l = [iter(a)]
         l.append(l)
diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py
index 1c2560c..0c6b0fe 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -899,7 +899,7 @@ class EventLoopTestsMixin:
     def test_internal_fds(self):
         loop = self.create_event_loop()
         if not isinstance(loop, selector_events.BaseSelectorEventLoop):
-            return
+            self.skipTest('loop is not a BaseSelectorEventLoop')
 
         self.assertEqual(1, loop._internal_fds)
         loop.close()
diff --git a/Lib/test/test_codecencodings_iso2022.py b/Lib/test/test_codecencodings_iso2022.py
index e4c1839..e4b2f30 100644
--- a/Lib/test/test_codecencodings_iso2022.py
+++ b/Lib/test/test_codecencodings_iso2022.py
@@ -36,6 +36,7 @@ class Test_ISO2022_KR(multibytecodec_support.TestBase, unittest.TestCase):
 
     # iso2022_kr.txt cannot be used to test "chunk coding": the escape
     # sequence is only written on the first line
+    @unittest.skip('iso2022_kr.txt cannot be used to test "chunk coding"')
     def test_chunkcoding(self):
         pass
 
diff --git a/Lib/test/test_configparser.py b/Lib/test/test_configparser.py
index 29e7ed9..78bd315 100644
--- a/Lib/test/test_configparser.py
+++ b/Lib/test/test_configparser.py
@@ -707,8 +707,7 @@ boolean {0[0]} NO
 
     def test_read_returns_file_list(self):
         if self.delimiters[0] != '=':
-            # skip reading the file if we're using an incompatible format
-            return
+            self.skipTest('incompatible format')
         file1 = support.findfile("cfgparser.1")
         # check when we pass a mix of readable and non-readable files:
         cf = self.newconfig()
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 6378ef3..d67df79 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -300,7 +300,6 @@ class IBMTestCases(unittest.TestCase):
                     #Exception raised where there shouldn't have been one.
                     self.fail('Exception "'+exception.__class__.__name__ + '" raised on line '+line)
 
-        return
 
     def eval_line(self, s):
         if s.find(' -> ') >= 0 and s[:2] != '--' and not s.startswith('  --'):
@@ -460,7 +459,6 @@ class IBMTestCases(unittest.TestCase):
 
         self.assertEqual(myexceptions, theirexceptions,
               'Incorrect flags set in ' + s + ' -- got ' + str(myexceptions))
-        return
 
     def getexceptions(self):
         return [e for e in Signals[self.decimal] if self.context.flags[e]]
@@ -1072,7 +1070,7 @@ class FormatTest(unittest.TestCase):
         try:
             from locale import CHAR_MAX
         except ImportError:
-            return
+            self.skipTest('locale.CHAR_MAX not available')
 
         def make_grouping(lst):
             return ''.join([chr(x) for x in lst]) if self.decimal == C else lst
@@ -1163,8 +1161,12 @@ class FormatTest(unittest.TestCase):
 
         decimal_point = locale.localeconv()['decimal_point']
         thousands_sep = locale.localeconv()['thousands_sep']
-        if decimal_point != '\u066b' or thousands_sep != '\u066c':
-            return
+        if decimal_point != '\u066b':
+            self.skipTest('inappropriate decimal point separator'
+                          '({!r} not {!r})'.format(decimal_point, '\u066b'))
+        if thousands_sep != '\u066c':
+            self.skipTest('inappropriate thousands separator'
+                          '({!r} not {!r})'.format(thousands_sep, '\u066c'))
 
         self.assertEqual(format(Decimal('100000000.123'), 'n'),
                          '100\u066c000\u066c000\u066b123')
@@ -1514,7 +1516,6 @@ def thfunc1(cls):
     cls.assertTrue(c1.flags[Inexact])
     for sig in Overflow, Underflow, DivisionByZero, InvalidOperation:
         cls.assertFalse(c1.flags[sig])
-    return
 
 def thfunc2(cls):
     Decimal = cls.decimal.Decimal
@@ -1559,7 +1560,6 @@ def thfunc2(cls):
     cls.assertTrue(thiscontext.flags[Inexact])
     for sig in Overflow, Underflow, DivisionByZero, InvalidOperation:
         cls.assertFalse(thiscontext.flags[sig])
-    return
 
 class ThreadingTest(unittest.TestCase):
     '''Unit tests for thread local contexts in Decimal.'''
@@ -1601,7 +1601,6 @@ class ThreadingTest(unittest.TestCase):
         DefaultContext.prec = save_prec
         DefaultContext.Emax = save_emax
         DefaultContext.Emin = save_emin
-        return
 
 @unittest.skipUnless(threading, 'threading required')
 class CThreadingTest(ThreadingTest):
@@ -4524,7 +4523,6 @@ class PyWhitebox(unittest.TestCase):
                 self.assertEqual(d1._sign, b1._sign)
                 self.assertEqual(d1._int, b1._int)
                 self.assertEqual(d1._exp, b1._exp)
-            return
 
         Decimal(d1)
         self.assertEqual(d1._sign, b1._sign)
@@ -5270,7 +5268,7 @@ class CWhitebox(unittest.TestCase):
         try:
             from locale import CHAR_MAX
         except ImportError:
-            return
+            self.skipTest('locale.CHAR_MAX not available')
 
         def make_grouping(lst):
             return ''.join([chr(x) for x in lst])
diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index 94d6be7..eb6ac3c 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -265,16 +265,18 @@ class DisTests(unittest.TestCase):
     def test_bug_708901(self):
         self.do_disassembly_test(bug708901, dis_bug708901)
 
+    # Test has been disabled due to change in the way
+    # list comps are handled. The byte code now includes
+    # a memory address and a file location, so they change from
+    # run to run.
+    @unittest.skip('disabled due to a change in the way list comps are handled')
     def test_bug_1333982(self):
         # XXX: re-enable this test!
         # This one is checking bytecodes generated for an `assert` statement,
         # so fails if the tests are run with -O.  Skip this test then.
-        pass # Test has been disabled due to change in the way
-             # list comps are handled. The byte code now includes
-             # a memory address and a file location, so they change from
-             # run to run.
-        # if __debug__:
-        #    self.do_disassembly_test(bug1333982, dis_bug1333982)
+
+        if __debug__:
+            self.do_disassembly_test(bug1333982, dis_bug1333982)
 
     def test_big_linenos(self):
         def func(count):
diff --git a/Lib/test/test_fileio.py b/Lib/test/test_fileio.py
index e678769..b10ea89 100644
--- a/Lib/test/test_fileio.py
+++ b/Lib/test/test_fileio.py
@@ -341,8 +341,7 @@ class OtherFileTests(unittest.TestCase):
         try:
             fn = TESTFN.encode("ascii")
         except UnicodeEncodeError:
-            # Skip test
-            return
+            self.skipTest('could not encode %r to ascii' % TESTFN)
         f = _FileIO(fn, "w")
         try:
             f.write(b"abc")
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index 5c2dc3f..e1e1f04 100644
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -71,7 +71,7 @@ class GeneralFloatCases(unittest.TestCase):
         # it still has to accept the normal python syntax
         import locale
         if not locale.localeconv()['decimal_point'] == ',':
-            return
+            self.skipTest('decimal_point is not ","')
 
         self.assertEqual(float("  3.14  "), 3.14)
         self.assertEqual(float("+3.14  "), 3.14)
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 38c9713..d044237 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -42,20 +42,6 @@ class TestPartial:
         self.assertEqual(p.func, capture)
         self.assertEqual(p.args, (1, 2))
         self.assertEqual(p.keywords, dict(a=10, b=20))
-        # attributes should not be writable
-        if not isinstance(self.partial, type):
-            return
-        self.assertRaises(AttributeError, setattr, p, 'func', map)
-        self.assertRaises(AttributeError, setattr, p, 'args', (1, 2))
-        self.assertRaises(AttributeError, setattr, p, 'keywords', dict(a=1, b=2))
-
-        p = self.partial(hex)
-        try:
-            del p.__dict__
-        except TypeError:
-            pass
-        else:
-            self.fail('partial object allowed __dict__ to be deleted')
 
     def test_argument_checking(self):
         self.assertRaises(TypeError, self.partial)     # need at least a func arg
@@ -151,6 +137,21 @@ class TestPartialC(TestPartial, unittest.TestCase):
     if c_functools:
         partial = c_functools.partial
 
+    def test_attributes_unwritable(self):
+        # attributes should not be writable
+        p = self.partial(capture, 1, 2, a=10, b=20)
+        self.assertRaises(AttributeError, setattr, p, 'func', map)
+        self.assertRaises(AttributeError, setattr, p, 'args', (1, 2))
+        self.assertRaises(AttributeError, setattr, p, 'keywords', dict(a=1, b=2))
+
+        p = self.partial(hex)
+        try:
+            del p.__dict__
+        except TypeError:
+            pass
+        else:
+            self.fail('partial object allowed __dict__ to be deleted')
+
     def test_repr(self):
         args = (object(), object())
         args_repr = ', '.join(repr(a) for a in args)
diff --git a/Lib/test/test_grp.py b/Lib/test/test_grp.py
index 04a8af6..749041c 100644
--- a/Lib/test/test_grp.py
+++ b/Lib/test/test_grp.py
@@ -26,8 +26,10 @@ class GroupDatabaseTestCase(unittest.TestCase):
         for e in entries:
             self.check_value(e)
 
+    def test_values_extended(self):
+        entries = grp.getgrall()
         if len(entries) > 1000:  # Huge group file (NIS?) -- skip the rest
-            return
+            self.skipTest('huge group file, extended test skipped')
 
         for e in entries:
             e2 = grp.getgrgid(e.gr_gid)
diff --git a/Lib/test/test_imp.py b/Lib/test/test_imp.py
index 78f5734..024f438 100644
--- a/Lib/test/test_imp.py
+++ b/Lib/test/test_imp.py
@@ -272,7 +272,7 @@ class ImportTests(unittest.TestCase):
         if found[0] is not None:
             found[0].close()
         if found[2][2] != imp.C_EXTENSION:
-            return
+            self.skipTest("found module doesn't appear to be a C extension")
         imp.load_module(name, None, *found[1:])
 
     @unittest.skipIf(sys.dont_write_bytecode,
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 57f3659..344425b 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -421,14 +421,9 @@ class IOTest(unittest.TestCase):
         # a long time to build the >2GB file and takes >2GB of disk space
         # therefore the resource must be enabled to run this test.
         if sys.platform[:3] == 'win' or sys.platform == 'darwin':
-            if not support.is_resource_enabled("largefile"):
-                print("\nTesting large file ops skipped on %s." % sys.platform,
-                      file=sys.stderr)
-                print("It requires %d bytes and a long time." % self.LARGE,
-                      file=sys.stderr)
-                print("Use 'regrtest.py -u largefile test_io' to run it.",
-                      file=sys.stderr)
-                return
+            support.requires(
+                'largefile',
+                'test requires %s bytes and a long time to run' % self.LARGE)
         with self.open(support.TESTFN, "w+b", 0) as f:
             self.large_file_ops(f)
         with self.open(support.TESTFN, "w+b") as f:
@@ -698,6 +693,7 @@ class CommonBufferedTests:
 
         self.assertEqual(42, bufio.fileno())
 
+    @unittest.skip('test having existential crisis')
     def test_no_fileno(self):
         # XXX will we always have fileno() function? If so, kill
         # this test. Else, write it.
diff --git a/Lib/test/test_memoryview.py b/Lib/test/test_memoryview.py
index ffd4f58..e7df8a7 100644
--- a/Lib/test/test_memoryview.py
+++ b/Lib/test/test_memoryview.py
@@ -57,7 +57,7 @@ class AbstractMemoryTests:
 
     def test_setitem_readonly(self):
         if not self.ro_type:
-            return
+            self.skipTest("no read-only type to test")
         b = self.ro_type(self._source)
         oldrefcount = sys.getrefcount(b)
         m = self._view(b)
@@ -71,7 +71,7 @@ class AbstractMemoryTests:
 
     def test_setitem_writable(self):
         if not self.rw_type:
-            return
+            self.skipTest("no writable type to test")
         tp = self.rw_type
         b = self.rw_type(self._source)
         oldrefcount = sys.getrefcount(b)
@@ -189,13 +189,13 @@ class AbstractMemoryTests:
 
     def test_attributes_readonly(self):
         if not self.ro_type:
-            return
+            self.skipTest("no read-only type to test")
         m = self.check_attributes_with_type(self.ro_type)
         self.assertEqual(m.readonly, True)
 
     def test_attributes_writable(self):
         if not self.rw_type:
-            return
+            self.skipTest("no writable type to test")
         m = self.check_attributes_with_type(self.rw_type)
         self.assertEqual(m.readonly, False)
 
@@ -301,7 +301,7 @@ class AbstractMemoryTests:
         # buffer as writable causing a segfault if using mmap
         tp = self.ro_type
         if tp is None:
-            return
+            self.skipTest("no read-only type to test")
         b = tp(self._source)
         m = self._view(b)
         i = io.BytesIO(b'ZZZZ')
@@ -379,12 +379,12 @@ class BaseArrayMemoryTests(AbstractMemoryTests):
     itemsize = array.array('i').itemsize
     format = 'i'
 
+    @unittest.skip('XXX test should be adapted for non-byte buffers')
     def test_getbuffer(self):
-        # XXX Test should be adapted for non-byte buffers
         pass
 
+    @unittest.skip('XXX NotImplementedError: tolist() only supports byte views')
     def test_tolist(self):
-        # XXX NotImplementedError: tolist() only supports byte views
         pass
 
 
diff --git a/Lib/test/test_nis.py b/Lib/test/test_nis.py
index 830c24d..a3a3c26 100644
--- a/Lib/test/test_nis.py
+++ b/Lib/test/test_nis.py
@@ -12,11 +12,7 @@ class NisTests(unittest.TestCase):
             maps = nis.maps()
         except nis.error as msg:
             # NIS is probably not active, so this test isn't useful
-            if support.verbose:
-                print("Test Skipped:", msg)
-            # Can't raise SkipTest as regrtest only recognizes the exception
-            #   import time.
-            return
+            self.skipTest(str(msg))
         try:
             # On some systems, this map is only accessible to the
             # super user
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index 285ef62..0991d15 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -218,7 +218,7 @@ class TestNtpath(unittest.TestCase):
             import nt
             tester('ntpath.abspath("C:\\")', "C:\\")
         except ImportError:
-            pass
+            self.skipTest('nt module not available')
 
     def test_relpath(self):
         currentdir = os.path.split(os.getcwd())[-1]
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 1ffa7da..fa6592d 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -508,7 +508,7 @@ class StatAttributeTests(unittest.TestCase):
         try:
             os.stat(r"c:\pagefile.sys")
         except FileNotFoundError:
-            pass # file does not exist; cannot run test
+            self.skipTest(r'c:\pagefile.sys does not exist')
         except OSError as e:
             self.fail("Could not stat pagefile.sys")
 
diff --git a/Lib/test/test_pwd.py b/Lib/test/test_pwd.py
index aa8f69f..37a1bcb 100644
--- a/Lib/test/test_pwd.py
+++ b/Lib/test/test_pwd.py
@@ -8,8 +8,6 @@ class PwdTest(unittest.TestCase):
 
     def test_values(self):
         entries = pwd.getpwall()
-        entriesbyname = {}
-        entriesbyuid = {}
 
         for e in entries:
             self.assertEqual(len(e), 7)
@@ -32,13 +30,20 @@ class PwdTest(unittest.TestCase):
             # for one uid
             #    self.assertEqual(pwd.getpwuid(e.pw_uid), e)
             # instead of this collect all entries for one uid
-            # and check afterwards
+            # and check afterwards (done in test_values_extended)
+
+    def test_values_extended(self):
+        entries = pwd.getpwall()
+        entriesbyname = {}
+        entriesbyuid = {}
+
+        if len(entries) > 1000:  # Huge passwd file (NIS?) -- skip this test
+            self.skipTest('passwd file is huge; extended test skipped')
+
+        for e in entries:
             entriesbyname.setdefault(e.pw_name, []).append(e)
             entriesbyuid.setdefault(e.pw_uid, []).append(e)
 
-        if len(entries) > 1000:  # Huge passwd file (NIS?) -- skip the rest
-            return
-
         # check whether the entry returned by getpwuid()
         # for each uid is among those from getpwall() for this uid
         for e in entries:
diff --git a/Lib/test/test_reprlib.py b/Lib/test/test_reprlib.py
index a504bde..5b81ce7 100644
--- a/Lib/test/test_reprlib.py
+++ b/Lib/test/test_reprlib.py
@@ -166,6 +166,7 @@ class ReprTests(unittest.TestCase):
         eq(r([[[[[[{}]]]]]]), "[[[[[[{}]]]]]]")
         eq(r([[[[[[[{}]]]]]]]), "[[[[[[[...]]]]]]]")
 
+    @unittest.skip('hard to catch a cell object')
     def test_cell(self):
         # XXX Hmm? How to get at a cell object?
         pass
@@ -274,6 +275,7 @@ class foo(object):
         eq(repr(foo.foo),
                "<class '%s.foo'>" % foo.__name__)
 
+    @unittest.skip('need a suitable object')
     def test_object(self):
         # XXX Test the repr of a type with a really long tp_name but with no
         # tp_repr.  WIBNI we had ::Inline? :)
@@ -321,6 +323,7 @@ class aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
             '<bound method aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.amethod of <%s.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa object at 0x' \
             % (qux.__name__,) ), r)
 
+    @unittest.skip('needs a built-in function with a really long name')
     def test_builtin_function(self):
         # XXX test built-in functions and methods with really long names
         pass
diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
index deb1577..98ea6d1 100644
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -753,11 +753,9 @@ class TestShutil(unittest.TestCase):
         self.assertEqual(os.stat(restrictive_subdir).st_mode,
                           os.stat(restrictive_subdir_dst).st_mode)
 
+    @unittest.skipIf(os.name == 'nt', 'temporarily disabled on Windows')
     @unittest.skipUnless(hasattr(os, 'link'), 'requires os.link')
     def test_dont_copy_file_onto_link_to_itself(self):
-        # Temporarily disable test on Windows.
-        if os.name == 'nt':
-            return
         # bug 851123.
         os.mkdir(TESTFN)
         src = os.path.join(TESTFN, 'cheese')
diff --git a/Lib/test/test_site.py b/Lib/test/test_site.py
index cb7c393..aab5860 100644
--- a/Lib/test/test_site.py
+++ b/Lib/test/test_site.py
@@ -370,6 +370,7 @@ class ImportSideEffectTests(unittest.TestCase):
             self.assertNotIn(path, seen_paths)
             seen_paths.add(path)
 
+    @unittest.skip('test not implemented')
     def test_add_build_dir(self):
         # Test that the build directory's Modules directory is used when it
         # should be.
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 3c9fbf0..bf42432 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -745,13 +745,13 @@ class GeneralModuleTests(unittest.TestCase):
             ip = socket.gethostbyname(hostname)
         except OSError:
             # Probably name lookup wasn't set up right; skip this test
-            return
+            self.skipTest('name lookup failure')
         self.assertTrue(ip.find('.') >= 0, "Error resolving host to ip.")
         try:
             hname, aliases, ipaddrs = socket.gethostbyaddr(ip)
         except OSError:
             # Probably a similar problem as above; skip this test
-            return
+            self.skipTest('name lookup failure')
         all_host_names = [hostname, hname] + aliases
         fqhn = socket.getfqdn(ip)
         if not fqhn in all_host_names:
@@ -977,16 +977,16 @@ class GeneralModuleTests(unittest.TestCase):
         try:
             from socket import inet_pton, AF_INET6, has_ipv6
             if not has_ipv6:
-                return
+                self.skipTest('IPv6 not available')
         except ImportError:
-            return
+            self.skipTest('could not import needed symbols from socket')
 
         if sys.platform == "win32":
             try:
                 inet_pton(AF_INET6, '::')
             except OSError as e:
                 if e.winerror == 10022:
-                    return # IPv6 might not be installed on this PC
+                    self.skipTest('IPv6 might not be supported')
 
         f = lambda a: inet_pton(AF_INET6, a)
         assertInvalid = lambda a: self.assertRaises(
@@ -1063,16 +1063,16 @@ class GeneralModuleTests(unittest.TestCase):
         try:
             from socket import inet_ntop, AF_INET6, has_ipv6
             if not has_ipv6:
-                return
+                self.skipTest('IPv6 not available')
         except ImportError:
-            return
+            self.skipTest('could not import needed symbols from socket')
 
         if sys.platform == "win32":
             try:
                 inet_ntop(AF_INET6, b'\x00' * 16)
             except OSError as e:
                 if e.winerror == 10022:
-                    return # IPv6 might not be installed on this PC
+                    self.skipTest('IPv6 might not be supported')
 
         f = lambda a: inet_ntop(AF_INET6, a)
         assertInvalid = lambda a: self.assertRaises(
@@ -1106,7 +1106,7 @@ class GeneralModuleTests(unittest.TestCase):
             my_ip_addr = socket.gethostbyname(socket.gethostname())
         except OSError:
             # Probably name lookup wasn't set up right; skip this test
-            return
+            self.skipTest('name lookup failure')
         self.assertIn(name[0], ("0.0.0.0", my_ip_addr), '%s invalid' % name[0])
         self.assertEqual(name[1], port)
 
diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py
index d5bc39d..13a72d4 100644
--- a/Lib/test/test_strptime.py
+++ b/Lib/test/test_strptime.py
@@ -323,7 +323,7 @@ class StrptimeTests(unittest.TestCase):
         # when time.tzname[0] == time.tzname[1] and time.daylight
         tz_name = time.tzname[0]
         if tz_name.upper() in ("UTC", "GMT"):
-            return
+            self.skipTest('need non-UTC/GMT timezone')
         try:
             original_tzname = time.tzname
             original_daylight = time.daylight
@@ -536,7 +536,7 @@ class CacheTests(unittest.TestCase):
         try:
             locale.setlocale(locale.LC_TIME, ('en_US', 'UTF8'))
         except locale.Error:
-            return
+            self.skipTest('test needs en_US.UTF8 locale')
         try:
             _strptime._strptime_time('10', '%d')
             # Get id of current cache object.
@@ -553,7 +553,7 @@ class CacheTests(unittest.TestCase):
             # If this is the case just suppress the exception and fall-through
             # to the resetting to the original locale.
             except locale.Error:
-                pass
+                self.skipTest('test needs de_DE.UTF8 locale')
         # Make sure we don't trample on the locale setting once we leave the
         # test.
         finally:
diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py
index ac4d860..2e99013 100644
--- a/Lib/test/test_tempfile.py
+++ b/Lib/test/test_tempfile.py
@@ -324,10 +324,9 @@ class TestMkstempInner(BaseTestCase):
         finally:
             os.rmdir(dir)
 
+    @unittest.skipUnless(has_stat, 'os.stat not available')
     def test_file_mode(self):
         # _mkstemp_inner creates files with the proper mode
-        if not has_stat:
-            return            # ugh, can't use SkipTest.
 
         file = self.do_create()
         mode = stat.S_IMODE(os.stat(file.name).st_mode)
@@ -339,10 +338,9 @@ class TestMkstempInner(BaseTestCase):
             expected = user * (1 + 8 + 64)
         self.assertEqual(mode, expected)
 
+    @unittest.skipUnless(has_spawnl, 'os.spawnl not available')
     def test_noinherit(self):
         # _mkstemp_inner file handles are not inherited by child processes
-        if not has_spawnl:
-            return            # ugh, can't use SkipTest.
 
         if support.verbose:
             v="v"
@@ -378,10 +376,9 @@ class TestMkstempInner(BaseTestCase):
                     "child process caught fatal signal %d" % -retval)
         self.assertFalse(retval > 0, "child process reports failure %d"%retval)
 
+    @unittest.skipUnless(has_textmode, "text mode not available")
     def test_textmode(self):
         # _mkstemp_inner can create files in text mode
-        if not has_textmode:
-            return            # ugh, can't use SkipTest.
 
         # A text file is truncated at the first Ctrl+Z byte
         f = self.do_create(bin=0)
@@ -571,10 +568,9 @@ class TestMkdtemp(BaseTestCase):
         finally:
             os.rmdir(dir)
 
+    @unittest.skipUnless(has_stat, 'os.stat not available')
     def test_mode(self):
         # mkdtemp creates directories with the proper mode
-        if not has_stat:
-            return            # ugh, can't use SkipTest.
 
         dir = self.do_create()
         try:
diff --git a/Lib/test/test_thread.py b/Lib/test/test_thread.py
index f9a721b..6144901 100644
--- a/Lib/test/test_thread.py
+++ b/Lib/test/test_thread.py
@@ -68,39 +68,35 @@ class ThreadRunningTests(BasicThreadTest):
         thread.stack_size(0)
         self.assertEqual(thread.stack_size(), 0, "stack_size not reset to default")
 
-        if os.name not in ("nt", "posix"):
-            return
-
-        tss_supported = True
+    @unittest.skipIf(os.name not in ("nt", "posix"), 'test meant for nt and posix')
+    def test_nt_and_posix_stack_size(self):
         try:
             thread.stack_size(4096)
         except ValueError:
             verbose_print("caught expected ValueError setting "
                             "stack_size(4096)")
         except thread.error:
-            tss_supported = False
-            verbose_print("platform does not support changing thread stack "
-                            "size")
-
-        if tss_supported:
-            fail_msg = "stack_size(%d) failed - should succeed"
-            for tss in (262144, 0x100000, 0):
-                thread.stack_size(tss)
-                self.assertEqual(thread.stack_size(), tss, fail_msg % tss)
-                verbose_print("successfully set stack_size(%d)" % tss)
-
-            for tss in (262144, 0x100000):
-                verbose_print("trying stack_size = (%d)" % tss)
-                self.next_ident = 0
-                self.created = 0
-                for i in range(NUMTASKS):
-                    self.newtask()
-
-                verbose_print("waiting for all tasks to complete")
-                self.done_mutex.acquire()
-                verbose_print("all tasks done")
-
-            thread.stack_size(0)
+            self.skipTest("platform does not support changing thread stack "
+                          "size")
+
+        fail_msg = "stack_size(%d) failed - should succeed"
+        for tss in (262144, 0x100000, 0):
+            thread.stack_size(tss)
+            self.assertEqual(thread.stack_size(), tss, fail_msg % tss)
+            verbose_print("successfully set stack_size(%d)" % tss)
+
+        for tss in (262144, 0x100000):
+            verbose_print("trying stack_size = (%d)" % tss)
+            self.next_ident = 0
+            self.created = 0
+            for i in range(NUMTASKS):
+                self.newtask()
+
+            verbose_print("waiting for all tasks to complete")
+            self.done_mutex.acquire()
+            verbose_print("all tasks done")
+
+        thread.stack_size(0)
 
     def test__count(self):
         # Test the _count() function.
diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py
index 44bcb94..048cb3b 100644
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -472,8 +472,7 @@ class TestLocale(unittest.TestCase):
         try:
             tmp = locale.setlocale(locale.LC_ALL, "fr_FR")
         except locale.Error:
-            # skip this test
-            return
+            self.skipTest('could not set locale.LC_ALL to fr_FR')
         # This should not cause an exception
         time.strftime("%B", (2009,2,1,0,0,0,0,0,0))
 
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index 575c4a5..c0d5dae 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -2002,12 +2002,12 @@ class UnicodeTest(string_tests.CommonTest,
         self.assertEqual(repr('\U00010000'), "'%c'" % (0x10000,)) # printable
         self.assertEqual(repr('\U00014000'), "'\\U00014000'")     # nonprintable
 
+    # This test only affects 32-bit platforms because expandtabs can only take
+    # an int as the max value, not a 64-bit C long.  If expandtabs is changed
+    # to take a 64-bit long, this test should apply to all platforms.
+    @unittest.skipIf(sys.maxsize > (1 << 32) or struct.calcsize('P') != 4,
+                     'only applies to 32-bit platforms')
     def test_expandtabs_overflows_gracefully(self):
-        # This test only affects 32-bit platforms because expandtabs can only take
-        # an int as the max value, not a 64-bit C long.  If expandtabs is changed
-        # to take a 64-bit long, this test should apply to all platforms.
-        if sys.maxsize > (1 << 32) or struct.calcsize('P') != 4:
-            return
         self.assertRaises(OverflowError, 't\tt\t'.expandtabs, sys.maxsize)
 
     @support.cpython_only
diff --git a/Lib/test/test_urllibnet.py b/Lib/test/test_urllibnet.py
index b6888f3..7214a67 100644
--- a/Lib/test/test_urllibnet.py
+++ b/Lib/test/test_urllibnet.py
@@ -98,11 +98,10 @@ class urlopenNetworkTests(unittest.TestCase):
                 open_url.close()
             self.assertEqual(code, 404)
 
+    # On Windows, socket handles are not file descriptors; this
+    # test can't pass on Windows.
+    @unittest.skipIf(sys.platform in ('win32',), 'not appropriate for Windows')
     def test_fileno(self):
-        if sys.platform in ('win32',):
-            # On Windows, socket handles are not file descriptors; this
-            # test can't pass on Windows.
-            return
         # Make sure fd returned by fileno is valid.
         with self.urlopen("http://www.python.org/", timeout=None) as open_url:
             fd = open_url.fileno()
diff --git a/Lib/test/test_warnings.py b/Lib/test/test_warnings.py
index 87463ac..ccdc65b 100644
--- a/Lib/test/test_warnings.py
+++ b/Lib/test/test_warnings.py
@@ -695,7 +695,7 @@ class CatchWarningTests(BaseTest):
         # Explicit tests for the test.support convenience wrapper
         wmod = self.module
         if wmod is not sys.modules['warnings']:
-            return
+            self.skipTest('module to test is not loaded warnings module')
         with support.check_warnings(quiet=False) as w:
             self.assertEqual(w.warnings, [])
             wmod.simplefilter("always")
diff --git a/Lib/test/test_xmlrpc_net.py b/Lib/test/test_xmlrpc_net.py
index 00aca19..4a3b64f 100644
--- a/Lib/test/test_xmlrpc_net.py
+++ b/Lib/test/test_xmlrpc_net.py
@@ -19,7 +19,6 @@ class PythonBuildersTest(unittest.TestCase):
             builders = server.getAllBuilders()
         except OSError as e:
             self.skipTest("network error: %s" % e)
-            return
         self.addCleanup(lambda: server('close')())
 
         # Perform a minimal sanity check on the result, just to be sure
diff --git a/Lib/test/test_zipimport.py b/Lib/test/test_zipimport.py
index 3f16041..1e351c8 100644
--- a/Lib/test/test_zipimport.py
+++ b/Lib/test/test_zipimport.py
@@ -136,7 +136,7 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
         # so we'll simply skip it then. Bug #765456.
         #
         if "zlib" in sys.builtin_module_names:
-            return
+            self.skipTest('zlib is a builtin module')
         if "zlib" in sys.modules:
             del sys.modules["zlib"]
         files = {"zlib.py": (NOW, test_src)}