Replace IOError with OSError (#16715)

44 files changed, 162 insertions, 162 deletions

diff --git a/Lib/test/fork_wait.py b/Lib/test/fork_wait.py
index 88527df..19b54ec 100644
--- a/Lib/test/fork_wait.py
+++ b/Lib/test/fork_wait.py
@@ -28,7 +28,7 @@ class ForkWait(unittest.TestCase):
             self.alive[id] = os.getpid()
             try:
                 time.sleep(SHORTSLEEP)
-            except IOError:
+            except OSError:
                 pass
 
     def wait_impl(self, cpid):
diff --git a/Lib/test/multibytecodec_support.py b/Lib/test/multibytecodec_support.py
index 26bac7b..dcaae7b 100644
--- a/Lib/test/multibytecodec_support.py
+++ b/Lib/test/multibytecodec_support.py
@@ -282,7 +282,7 @@ class TestBase_Mapping(unittest.TestCase):
         unittest.TestCase.__init__(self, *args, **kw)
         try:
             self.open_mapping_file().close() # test it to report the error early
-        except (IOError, HTTPException):
+        except (OSError, HTTPException):
             self.skipTest("Could not retrieve "+self.mapfileurl)
 
     def open_mapping_file(self):
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 5d9d82d..4e6064c 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -506,7 +506,7 @@ def main(tests=None, testdir=None, verbose=0, quiet=False,
             next_test = fp.read().strip()
             tests = [next_test]
             fp.close()
-        except IOError:
+        except OSError:
             pass
 
     if fromfile:
diff --git a/Lib/test/sortperf.py b/Lib/test/sortperf.py
index a370ed9..90722f7 100644
--- a/Lib/test/sortperf.py
+++ b/Lib/test/sortperf.py
@@ -22,7 +22,7 @@ def randfloats(n):
     fn = os.path.join(td, "rr%06d" % n)
     try:
         fp = open(fn, "rb")
-    except IOError:
+    except OSError:
         r = random.random
         result = [r() for i in range(n)]
         try:
@@ -37,7 +37,7 @@ def randfloats(n):
                         os.unlink(fn)
                     except OSError:
                         pass
-        except IOError as msg:
+        except OSError as msg:
             print("can't write", fn, ":", msg)
     else:
         result = marshal.load(fp)
diff --git a/Lib/test/support.py b/Lib/test/support.py
index d776b99..dab0f1b 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -1097,9 +1097,9 @@ class TransientResource(object):
 # Context managers that raise ResourceDenied when various issues
 # with the Internet connection manifest themselves as exceptions.
 # XXX deprecate these and use transient_internet() instead
-time_out = TransientResource(IOError, errno=errno.ETIMEDOUT)
+time_out = TransientResource(OSError, errno=errno.ETIMEDOUT)
 socket_peer_reset = TransientResource(OSError, errno=errno.ECONNRESET)
-ioerror_peer_reset = TransientResource(IOError, errno=errno.ECONNRESET)
+ioerror_peer_reset = TransientResource(OSError, errno=errno.ECONNRESET)
 
 
 @contextlib.contextmanager
@@ -1145,17 +1145,17 @@ def transient_internet(resource_name, *, timeout=30.0, errnos=()):
         if timeout is not None:
             socket.setdefaulttimeout(timeout)
         yield
-    except IOError as err:
+    except OSError as err:
         # urllib can wrap original socket errors multiple times (!), we must
         # unwrap to get at the original error.
         while True:
             a = err.args
-            if len(a) >= 1 and isinstance(a[0], IOError):
+            if len(a) >= 1 and isinstance(a[0], OSError):
                 err = a[0]
             # The error can also be wrapped as args[1]:
             #    except socket.error as msg:
-            #        raise IOError('socket error', msg).with_traceback(sys.exc_info()[2])
-            elif len(a) >= 2 and isinstance(a[1], IOError):
+            #        raise OSError('socket error', msg).with_traceback(sys.exc_info()[2])
+            elif len(a) >= 2 and isinstance(a[1], OSError):
                 err = a[1]
             else:
                 break
diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index 544c2ce..9c19b57 100755
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -355,12 +355,12 @@ class BaseTest(unittest.TestCase):
             support.unlink(support.TESTFN)
 
     def test_fromfile_ioerror(self):
-        # Issue #5395: Check if fromfile raises a proper IOError
+        # Issue #5395: Check if fromfile raises a proper OSError
         # instead of EOFError.
         a = array.array(self.typecode)
         f = open(support.TESTFN, 'wb')
         try:
-            self.assertRaises(IOError, a.fromfile, f, len(self.example))
+            self.assertRaises(OSError, a.fromfile, f, len(self.example))
         finally:
             f.close()
             support.unlink(support.TESTFN)
diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 24a1813..fb2f782 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -253,8 +253,8 @@ class BZ2FileTest(BaseTest):
             bz2f.write(b"abc")
 
         with BZ2File(self.filename, "r") as bz2f:
-            self.assertRaises(IOError, bz2f.write, b"a")
-            self.assertRaises(IOError, bz2f.writelines, [b"a"])
+            self.assertRaises(OSError, bz2f.write, b"a")
+            self.assertRaises(OSError, bz2f.writelines, [b"a"])
 
     def testAppend(self):
         with BZ2File(self.filename, "w") as bz2f:
@@ -429,7 +429,7 @@ class BZ2FileTest(BaseTest):
             del o
 
     def testOpenNonexistent(self):
-        self.assertRaises(IOError, BZ2File, "/non/existent")
+        self.assertRaises(OSError, BZ2File, "/non/existent")
 
     def testReadlinesNoNewline(self):
         # Issue #1191043: readlines() fails on a file containing no newline.
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
index 96f8aa7..3dc3836 100644
--- a/Lib/test/test_csv.py
+++ b/Lib/test/test_csv.py
@@ -136,12 +136,12 @@ class Test_Csv(unittest.TestCase):
                 return 10;
             def __getitem__(self, i):
                 if i > 2:
-                    raise IOError
-        self.assertRaises(IOError, self._write_test, BadList(), '')
+                    raise OSError
+        self.assertRaises(OSError, self._write_test, BadList(), '')
         class BadItem:
             def __str__(self):
-                raise IOError
-        self.assertRaises(IOError, self._write_test, [BadItem()], '')
+                raise OSError
+        self.assertRaises(OSError, self._write_test, [BadItem()], '')
 
     def test_write_bigfield(self):
         # This exercises the buffer realloc functionality
@@ -186,9 +186,9 @@ class Test_Csv(unittest.TestCase):
     def test_writerows(self):
         class BrokenFile:
             def write(self, buf):
-                raise IOError
+                raise OSError
         writer = csv.writer(BrokenFile())
-        self.assertRaises(IOError, writer.writerows, [['a']])
+        self.assertRaises(OSError, writer.writerows, [['a']])
 
         with TemporaryFile("w+", newline='') as fileobj:
             writer = csv.writer(fileobj)
diff --git a/Lib/test/test_dbm.py b/Lib/test/test_dbm.py
index 02df7e3..95301bf 100644
--- a/Lib/test/test_dbm.py
+++ b/Lib/test/test_dbm.py
@@ -57,7 +57,7 @@ class AnyDBMTestCase(unittest.TestCase):
         return keys
 
     def test_error(self):
-        self.assertTrue(issubclass(self.module.error, IOError))
+        self.assertTrue(issubclass(self.module.error, OSError))
 
     def test_anydbm_not_existing(self):
         self.assertRaises(dbm.error, dbm.open, _fname)
diff --git a/Lib/test/test_email/torture_test.py b/Lib/test/test_email/torture_test.py
index 544b1bb..19cf64f 100644
--- a/Lib/test/test_email/torture_test.py
+++ b/Lib/test/test_email/torture_test.py
@@ -27,7 +27,7 @@ def openfile(filename):
 # Prevent this test from running in the Python distro
 try:
     openfile('crispin-torture.txt')
-except IOError:
+except OSError:
     raise TestSkipped
 
 
diff --git a/Lib/test/test_epoll.py b/Lib/test/test_epoll.py
index a3d4e2d..7077a70 100644
--- a/Lib/test/test_epoll.py
+++ b/Lib/test/test_epoll.py
@@ -33,7 +33,7 @@ if not hasattr(select, "epoll"):
 
 try:
     select.epoll()
-except IOError as e:
+except OSError as e:
     if e.errno == errno.ENOSYS:
         raise unittest.SkipTest("kernel doesn't support epoll()")
     raise
@@ -122,12 +122,12 @@ class TestEPoll(unittest.TestCase):
             # ValueError: file descriptor cannot be a negative integer (-1)
             self.assertRaises(ValueError, ep.register, -1,
                 select.EPOLLIN | select.EPOLLOUT)
-            # IOError: [Errno 9] Bad file descriptor
-            self.assertRaises(IOError, ep.register, 10000,
+            # OSError: [Errno 9] Bad file descriptor
+            self.assertRaises(OSError, ep.register, 10000,
                 select.EPOLLIN | select.EPOLLOUT)
             # registering twice also raises an exception
             ep.register(server, select.EPOLLIN | select.EPOLLOUT)
-            self.assertRaises(IOError, ep.register, server,
+            self.assertRaises(OSError, ep.register, server,
                 select.EPOLLIN | select.EPOLLOUT)
         finally:
             ep.close()
@@ -149,7 +149,7 @@ class TestEPoll(unittest.TestCase):
         ep.close()
         try:
             ep2.poll(1, 4)
-        except IOError as e:
+        except OSError as e:
             self.assertEqual(e.args[0], errno.EBADF, e)
         else:
             self.fail("epoll on closed fd didn't raise EBADF")
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 6fa1f5b..2f39d4b 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -244,16 +244,16 @@ class ExceptionTests(unittest.TestCase):
                 {'args' : ('foo', 1)}),
             (SystemExit, ('foo',),
                 {'args' : ('foo',), 'code' : 'foo'}),
-            (IOError, ('foo',),
+            (OSError, ('foo',),
                 {'args' : ('foo',), 'filename' : None,
                  'errno' : None, 'strerror' : None}),
-            (IOError, ('foo', 'bar'),
+            (OSError, ('foo', 'bar'),
                 {'args' : ('foo', 'bar'), 'filename' : None,
                  'errno' : 'foo', 'strerror' : 'bar'}),
-            (IOError, ('foo', 'bar', 'baz'),
+            (OSError, ('foo', 'bar', 'baz'),
                 {'args' : ('foo', 'bar'), 'filename' : 'baz',
                  'errno' : 'foo', 'strerror' : 'bar'}),
-            (IOError, ('foo', 'bar', 'baz', 'quux'),
+            (OSError, ('foo', 'bar', 'baz', 'quux'),
                 {'args' : ('foo', 'bar', 'baz', 'quux')}),
             (OSError, ('errnoStr', 'strErrorStr', 'filenameStr'),
                 {'args' : ('errnoStr', 'strErrorStr'),
diff --git a/Lib/test/test_file.py b/Lib/test/test_file.py
index bb0da79..d5eca2b 100644
--- a/Lib/test/test_file.py
+++ b/Lib/test/test_file.py
@@ -87,7 +87,7 @@ class AutoFileTests(unittest.TestCase):
         self.assertTrue(not f.closed)
 
         if hasattr(f, "readinto"):
-            self.assertRaises((IOError, TypeError), f.readinto, "")
+            self.assertRaises((OSError, TypeError), f.readinto, "")
         f.close()
         self.assertTrue(f.closed)
 
@@ -126,7 +126,7 @@ class AutoFileTests(unittest.TestCase):
             self.assertEqual(self.f.__exit__(*sys.exc_info()), None)
 
     def testReadWhenWriting(self):
-        self.assertRaises(IOError, self.f.read)
+        self.assertRaises(OSError, self.f.read)
 
 class CAutoFileTests(AutoFileTests):
     open = io.open
@@ -151,12 +151,12 @@ class OtherFileTests(unittest.TestCase):
     def testStdin(self):
         # This causes the interpreter to exit on OSF1 v5.1.
         if sys.platform != 'osf1V5':
-            self.assertRaises((IOError, ValueError), sys.stdin.seek, -1)
+            self.assertRaises((OSError, ValueError), sys.stdin.seek, -1)
         else:
             print((
                 '  Skipping sys.stdin.seek(-1), it may crash the interpreter.'
                 ' Test manually.'), file=sys.__stdout__)
-        self.assertRaises((IOError, ValueError), sys.stdin.truncate)
+        self.assertRaises((OSError, ValueError), sys.stdin.truncate)
 
     def testBadModeArgument(self):
         # verify that we get a sensible error message for bad mode argument
@@ -187,7 +187,7 @@ class OtherFileTests(unittest.TestCase):
                 d = int(f.read().decode("ascii"))
                 f.close()
                 f.close()
-            except IOError as msg:
+            except OSError as msg:
                 self.fail('error setting buffer size %d: %s' % (s, str(msg)))
             self.assertEqual(d, s)
 
diff --git a/Lib/test/test_fileinput.py b/Lib/test/test_fileinput.py
index 1e70641..c42e3e8 100644
--- a/Lib/test/test_fileinput.py
+++ b/Lib/test/test_fileinput.py
@@ -275,8 +275,8 @@ class FileInputTests(unittest.TestCase):
         try:
             t1 = writeTmp(1, [""])
             with FileInput(files=t1) as fi:
-                raise IOError
-        except IOError:
+                raise OSError
+        except OSError:
             self.assertEqual(fi._files, ())
         finally:
             remove_tempfiles(t1)
diff --git a/Lib/test/test_fileio.py b/Lib/test/test_fileio.py
index 9615c3a..0badf51 100644
--- a/Lib/test/test_fileio.py
+++ b/Lib/test/test_fileio.py
@@ -144,16 +144,16 @@ class AutoFileTests(unittest.TestCase):
         # Unix calls dircheck() and returns "[Errno 21]: Is a directory"
         try:
             _FileIO('.', 'r')
-        except IOError as e:
+        except OSError as e:
             self.assertNotEqual(e.errno, 0)
             self.assertEqual(e.filename, ".")
         else:
-            self.fail("Should have raised IOError")
+            self.fail("Should have raised OSError")
 
     @unittest.skipIf(os.name == 'nt', "test only works on a POSIX-like system")
     def testOpenDirFD(self):
         fd = os.open('.', os.O_RDONLY)
-        with self.assertRaises(IOError) as cm:
+        with self.assertRaises(OSError) as cm:
             _FileIO(fd, 'r')
         os.close(fd)
         self.assertEqual(cm.exception.errno, errno.EISDIR)
@@ -171,7 +171,7 @@ class AutoFileTests(unittest.TestCase):
             finally:
                 try:
                     self.f.close()
-                except IOError:
+                except OSError:
                     pass
         return wrapper
 
@@ -183,14 +183,14 @@ class AutoFileTests(unittest.TestCase):
             os.close(f.fileno())
             try:
                 func(self, f)
-            except IOError as e:
+            except OSError as e:
                 self.assertEqual(e.errno, errno.EBADF)
             else:
-                self.fail("Should have raised IOError")
+                self.fail("Should have raised OSError")
             finally:
                 try:
                     self.f.close()
-                except IOError:
+                except OSError:
                     pass
         return wrapper
 
@@ -237,7 +237,7 @@ class AutoFileTests(unittest.TestCase):
     def ReopenForRead(self):
         try:
             self.f.close()
-        except IOError:
+        except OSError:
             pass
         self.f = _FileIO(TESTFN, 'r')
         os.close(self.f.fileno())
@@ -346,7 +346,7 @@ class OtherFileTests(unittest.TestCase):
         self.assertRaises(OSError, _FileIO, make_bad_fd())
         if sys.platform == 'win32':
             import msvcrt
-            self.assertRaises(IOError, msvcrt.get_osfhandle, make_bad_fd())
+            self.assertRaises(OSError, msvcrt.get_osfhandle, make_bad_fd())
 
     def testBadModeArgument(self):
         # verify that we get a sensible error message for bad mode argument
diff --git a/Lib/test/test_ftplib.py b/Lib/test/test_ftplib.py
index 861d670..4dfc457 100644
--- a/Lib/test/test_ftplib.py
+++ b/Lib/test/test_ftplib.py
@@ -482,7 +482,7 @@ class TestFTPClass(TestCase):
 
     def test_all_errors(self):
         exceptions = (ftplib.error_reply, ftplib.error_temp, ftplib.error_perm,
-                      ftplib.error_proto, ftplib.Error, IOError, EOFError)
+                      ftplib.error_proto, ftplib.Error, OSError, EOFError)
         for x in exceptions:
             try:
                 raise x('exception not included in all_errors set')
@@ -721,7 +721,7 @@ class TestFTPClass(TestCase):
                                 source_address=(HOST, port))
             self.assertEqual(self.client.sock.getsockname()[1], port)
             self.client.quit()
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.EADDRINUSE:
                 self.skipTest("couldn't bind to port %d" % port)
             raise
@@ -732,7 +732,7 @@ class TestFTPClass(TestCase):
         try:
             with self.client.transfercmd('list') as sock:
                 self.assertEqual(sock.getsockname()[1], port)
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.EADDRINUSE:
                 self.skipTest("couldn't bind to port %d" % port)
             raise
diff --git a/Lib/test/test_imaplib.py b/Lib/test/test_imaplib.py
index 06776de..0e15fa3 100644
--- a/Lib/test/test_imaplib.py
+++ b/Lib/test/test_imaplib.py
@@ -114,7 +114,7 @@ class SimpleIMAPHandler(socketserver.StreamRequestHandler):
                         # Naked sockets return empty strings..
                         return
                     line += part
-                except IOError:
+                except OSError:
                     # ..but SSLSockets raise exceptions.
                     return
                 if line.endswith(b'\r\n'):
diff --git a/Lib/test/test_importlib/source/test_abc_loader.py b/Lib/test/test_importlib/source/test_abc_loader.py
index cce7b07..718a548 100644
--- a/Lib/test/test_importlib/source/test_abc_loader.py
+++ b/Lib/test/test_importlib/source/test_abc_loader.py
@@ -59,7 +59,7 @@ class SourceLoaderMock(SourceOnlyLoaderMock):
         elif path == self.bytecode_path:
             return self.bytecode
         else:
-            raise IOError
+            raise OSError
 
     def path_stats(self, path):
         assert path == self.path
@@ -125,12 +125,12 @@ class SourceOnlyLoaderTests(SourceLoaderTestHarness):
 
     def test_get_source(self):
         # Verify the source code is returned as a string.
-        # If an IOError is raised by get_data then raise ImportError.
+        # If an OSError is raised by get_data then raise ImportError.
         expected_source = self.loader.source.decode('utf-8')
         self.assertEqual(self.loader.get_source(self.name), expected_source)
-        def raise_IOError(path):
-            raise IOError
-        self.loader.get_data = raise_IOError
+        def raise_OSError(path):
+            raise OSError
+        self.loader.get_data = raise_OSError
         with self.assertRaises(ImportError) as cm:
             self.loader.get_source(self.name)
         self.assertEqual(cm.exception.name, self.name)
@@ -216,7 +216,7 @@ class SourceLoaderBytecodeTests(SourceLoaderTestHarness):
         # If no bytecode exists then move on to the source.
         self.loader.bytecode_path = "<does not exist>"
         # Sanity check
-        with self.assertRaises(IOError):
+        with self.assertRaises(OSError):
             bytecode_path = imp.cache_from_source(self.path)
             self.loader.get_data(bytecode_path)
         code_object = self.loader.get_code(self.name)
@@ -265,7 +265,7 @@ class SourceLoaderBytecodeTests(SourceLoaderTestHarness):
             self.loader.__class__.set_data = original_set_data
 
     def test_set_data_raises_exceptions(self):
-        # Raising NotImplementedError or IOError is okay for set_data.
+        # Raising NotImplementedError or OSError is okay for set_data.
         def raise_exception(exc):
             def closure(*args, **kwargs):
                 raise exc
diff --git a/Lib/test/test_importlib/source/test_file_loader.py b/Lib/test/test_importlib/source/test_file_loader.py
index 90f9d30..dd28e8f 100644
--- a/Lib/test/test_importlib/source/test_file_loader.py
+++ b/Lib/test/test_importlib/source/test_file_loader.py
@@ -407,7 +407,7 @@ class SourceLoaderBadBytecodeTest(BadBytecodeTest):
             os.chmod(bytecode_path,
                         stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH)
             try:
-                # Should not raise IOError!
+                # Should not raise OSError!
                 self.import_(mapping['_temp'], '_temp')
             finally:
                 # Make writable for eventual clean-up.
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 80db03b..0ab414d 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -401,14 +401,14 @@ class TestBuggyCases(GetSourceBase):
             unicodedata.__file__[-4:] in (".pyc", ".pyo"),
         "unicodedata is not an external binary module")
     def test_findsource_binary(self):
-        self.assertRaises(IOError, inspect.getsource, unicodedata)
-        self.assertRaises(IOError, inspect.findsource, unicodedata)
+        self.assertRaises(OSError, inspect.getsource, unicodedata)
+        self.assertRaises(OSError, inspect.findsource, unicodedata)
 
     def test_findsource_code_in_linecache(self):
         lines = ["x=1"]
         co = compile(lines[0], "_dynamically_created_file", "exec")
-        self.assertRaises(IOError, inspect.findsource, co)
-        self.assertRaises(IOError, inspect.getsource, co)
+        self.assertRaises(OSError, inspect.findsource, co)
+        self.assertRaises(OSError, inspect.getsource, co)
         linecache.cache[co.co_filename] = (1, None, lines, co.co_filename)
         try:
             self.assertEqual(inspect.findsource(co), (lines,0))
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 28d3e0f..7906060 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -164,7 +164,7 @@ class CloseFailureIO(MockRawIO):
     def close(self):
         if not self.closed:
             self.closed = 1
-            raise IOError
+            raise OSError
 
 class CCloseFailureIO(CloseFailureIO, io.RawIOBase):
     pass
@@ -600,9 +600,9 @@ class IOTest(unittest.TestCase):
     def test_flush_error_on_close(self):
         f = self.open(support.TESTFN, "wb", buffering=0)
         def bad_flush():
-            raise IOError()
+            raise OSError()
         f.flush = bad_flush
-        self.assertRaises(IOError, f.close) # exception not swallowed
+        self.assertRaises(OSError, f.close) # exception not swallowed
         self.assertTrue(f.closed)
 
     def test_multi_close(self):
@@ -761,7 +761,7 @@ class CommonBufferedTests:
         if s:
             # The destructor *may* have printed an unraisable error, check it
             self.assertEqual(len(s.splitlines()), 1)
-            self.assertTrue(s.startswith("Exception IOError: "), s)
+            self.assertTrue(s.startswith("Exception OSError: "), s)
             self.assertTrue(s.endswith(" ignored"), s)
 
     def test_repr(self):
@@ -777,22 +777,22 @@ class CommonBufferedTests:
     def test_flush_error_on_close(self):
         raw = self.MockRawIO()
         def bad_flush():
-            raise IOError()
+            raise OSError()
         raw.flush = bad_flush
         b = self.tp(raw)
-        self.assertRaises(IOError, b.close) # exception not swallowed
+        self.assertRaises(OSError, b.close) # exception not swallowed
         self.assertTrue(b.closed)
 
     def test_close_error_on_close(self):
         raw = self.MockRawIO()
         def bad_flush():
-            raise IOError('flush')
+            raise OSError('flush')
         def bad_close():
-            raise IOError('close')
+            raise OSError('close')
         raw.close = bad_close
         b = self.tp(raw)
         b.flush = bad_flush
-        with self.assertRaises(IOError) as err: # exception not swallowed
+        with self.assertRaises(OSError) as err: # exception not swallowed
             b.close()
         self.assertEqual(err.exception.args, ('close',))
         self.assertEqual(err.exception.__context__.args, ('flush',))
@@ -1014,8 +1014,8 @@ class BufferedReaderTest(unittest.TestCase, CommonBufferedTests):
     def test_misbehaved_io(self):
         rawio = self.MisbehavedRawIO((b"abc", b"d", b"efg"))
         bufio = self.tp(rawio)
-        self.assertRaises(IOError, bufio.seek, 0)
-        self.assertRaises(IOError, bufio.tell)
+        self.assertRaises(OSError, bufio.seek, 0)
+        self.assertRaises(OSError, bufio.tell)
 
     def test_no_extraneous_read(self):
         # Issue #9550; when the raw IO object has satisfied the read request,
@@ -1066,7 +1066,7 @@ class CBufferedReaderTest(BufferedReaderTest, SizeofTest):
         bufio = self.tp(rawio)
         # _pyio.BufferedReader seems to implement reading different, so that
         # checking this is not so easy.
-        self.assertRaises(IOError, bufio.read, 10)
+        self.assertRaises(OSError, bufio.read, 10)
 
     def test_garbage_collection(self):
         # C BufferedReader objects are collected.
@@ -1313,9 +1313,9 @@ class BufferedWriterTest(unittest.TestCase, CommonBufferedTests):
     def test_misbehaved_io(self):
         rawio = self.MisbehavedRawIO()
         bufio = self.tp(rawio, 5)
-        self.assertRaises(IOError, bufio.seek, 0)
-        self.assertRaises(IOError, bufio.tell)
-        self.assertRaises(IOError, bufio.write, b"abcdef")
+        self.assertRaises(OSError, bufio.seek, 0)
+        self.assertRaises(OSError, bufio.tell)
+        self.assertRaises(OSError, bufio.write, b"abcdef")
 
     def test_max_buffer_size_removal(self):
         with self.assertRaises(TypeError):
@@ -1324,11 +1324,11 @@ class BufferedWriterTest(unittest.TestCase, CommonBufferedTests):
     def test_write_error_on_close(self):
         raw = self.MockRawIO()
         def bad_write(b):
-            raise IOError()
+            raise OSError()
         raw.write = bad_write
         b = self.tp(raw)
         b.write(b'spam')
-        self.assertRaises(IOError, b.close) # exception not swallowed
+        self.assertRaises(OSError, b.close) # exception not swallowed
         self.assertTrue(b.closed)
 
 
@@ -1393,14 +1393,14 @@ class BufferedRWPairTest(unittest.TestCase):
             def readable(self):
                 return False
 
-        self.assertRaises(IOError, self.tp, NotReadable(), self.MockRawIO())
+        self.assertRaises(OSError, self.tp, NotReadable(), self.MockRawIO())
 
     def test_constructor_with_not_writeable(self):
         class NotWriteable(MockRawIO):
             def writable(self):
                 return False
 
-        self.assertRaises(IOError, self.tp, self.MockRawIO(), NotWriteable())
+        self.assertRaises(OSError, self.tp, self.MockRawIO(), NotWriteable())
 
     def test_read(self):
         pair = self.tp(self.BytesIO(b"abcdef"), self.MockRawIO())
@@ -2146,7 +2146,7 @@ class TextIOWrapperTest(unittest.TestCase):
         if s:
             # The destructor *may* have printed an unraisable error, check it
             self.assertEqual(len(s.splitlines()), 1)
-            self.assertTrue(s.startswith("Exception IOError: "), s)
+            self.assertTrue(s.startswith("Exception OSError: "), s)
             self.assertTrue(s.endswith(" ignored"), s)
 
     # Systematic tests of the text I/O API
@@ -2218,7 +2218,7 @@ class TextIOWrapperTest(unittest.TestCase):
         f.seek(0)
         for line in f:
             self.assertEqual(line, "\xff\n")
-            self.assertRaises(IOError, f.tell)
+            self.assertRaises(OSError, f.tell)
         self.assertEqual(f.tell(), p2)
         f.close()
 
@@ -2322,7 +2322,7 @@ class TextIOWrapperTest(unittest.TestCase):
             def readable(self):
                 return False
         txt = self.TextIOWrapper(UnReadable())
-        self.assertRaises(IOError, txt.read)
+        self.assertRaises(OSError, txt.read)
 
     def test_read_one_by_one(self):
         txt = self.TextIOWrapper(self.BytesIO(b"AA\r\nBB"))
@@ -2497,9 +2497,9 @@ class TextIOWrapperTest(unittest.TestCase):
     def test_flush_error_on_close(self):
         txt = self.TextIOWrapper(self.BytesIO(self.testdata), encoding="ascii")
         def bad_flush():
-            raise IOError()
+            raise OSError()
         txt.flush = bad_flush
-        self.assertRaises(IOError, txt.close) # exception not swallowed
+        self.assertRaises(OSError, txt.close) # exception not swallowed
         self.assertTrue(txt.closed)
 
     def test_multi_close(self):
@@ -3032,7 +3032,7 @@ class SignalsTest(unittest.TestCase):
             # buffer, and block again.
             try:
                 wio.close()
-            except IOError as e:
+            except OSError as e:
                 if e.errno != errno.EBADF:
                     raise
 
@@ -3160,7 +3160,7 @@ class SignalsTest(unittest.TestCase):
             # buffer, and could block (in case of failure).
             try:
                 wio.close()
-            except IOError as e:
+            except OSError as e:
                 if e.errno != errno.EBADF:
                     raise
 
diff --git a/Lib/test/test_ioctl.py b/Lib/test/test_ioctl.py
index 531c9af..7eb324a 100644
--- a/Lib/test/test_ioctl.py
+++ b/Lib/test/test_ioctl.py
@@ -8,7 +8,7 @@ get_attribute(termios, 'TIOCGPGRP') #Can't run tests without this feature
 
 try:
     tty = open("/dev/tty", "rb")
-except IOError:
+except OSError:
     raise unittest.SkipTest("Unable to open /dev/tty")
 else:
     # Skip if another process is in foreground
diff --git a/Lib/test/test_largefile.py b/Lib/test/test_largefile.py
index 1c6297a..7502dc3 100644
--- a/Lib/test/test_largefile.py
+++ b/Lib/test/test_largefile.py
@@ -14,7 +14,7 @@ try:
     import signal
     # The default handler for SIGXFSZ is to abort the process.
     # By ignoring it, system calls exceeding the file size resource
-    # limit will raise IOError instead of crashing the interpreter.
+    # limit will raise OSError instead of crashing the interpreter.
     oldhandler = signal.signal(signal.SIGXFSZ, signal.SIG_IGN)
 except (ImportError, AttributeError):
     pass
@@ -162,7 +162,7 @@ def test_main():
             # flush, too!
             f.write(b'x')
             f.flush()
-        except (IOError, OverflowError):
+        except (OSError, OverflowError):
             f.close()
             unlink(TESTFN)
             raise unittest.SkipTest("filesystem does not have largefile support")
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index d8ce315..c6cd64a 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -3183,13 +3183,13 @@ class ShutdownTest(BaseTest):
         self.assertEqual('0 - release', self.called[-1])
 
     def test_with_ioerror_in_acquire(self):
-        self._test_with_failure_in_method('acquire', IOError)
+        self._test_with_failure_in_method('acquire', OSError)
 
     def test_with_ioerror_in_flush(self):
-        self._test_with_failure_in_method('flush', IOError)
+        self._test_with_failure_in_method('flush', OSError)
 
     def test_with_ioerror_in_close(self):
-        self._test_with_failure_in_method('close', IOError)
+        self._test_with_failure_in_method('close', OSError)
 
     def test_with_valueerror_in_acquire(self):
         self._test_with_failure_in_method('acquire', ValueError)
diff --git a/Lib/test/test_memoryio.py b/Lib/test/test_memoryio.py
index e5db945..9e1b7c7 100644
--- a/Lib/test/test_memoryio.py
+++ b/Lib/test/test_memoryio.py
@@ -520,12 +520,12 @@ class TextIOTestMixin:
     def test_relative_seek(self):
         memio = self.ioclass()
 
-        self.assertRaises(IOError, memio.seek, -1, 1)
-        self.assertRaises(IOError, memio.seek, 3, 1)
-        self.assertRaises(IOError, memio.seek, -3, 1)
-        self.assertRaises(IOError, memio.seek, -1, 2)
-        self.assertRaises(IOError, memio.seek, 1, 1)
-        self.assertRaises(IOError, memio.seek, 1, 2)
+        self.assertRaises(OSError, memio.seek, -1, 1)
+        self.assertRaises(OSError, memio.seek, 3, 1)
+        self.assertRaises(OSError, memio.seek, -3, 1)
+        self.assertRaises(OSError, memio.seek, -1, 2)
+        self.assertRaises(OSError, memio.seek, 1, 1)
+        self.assertRaises(OSError, memio.seek, 1, 2)
 
     def test_textio_properties(self):
         memio = self.ioclass()
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index e341bc7..3d883a9 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -684,11 +684,11 @@ class MmapTests(unittest.TestCase):
         self.assertTrue(m.closed)
 
     def test_context_manager_exception(self):
-        # Test that the IOError gets passed through
+        # Test that the OSError gets passed through
         with self.assertRaises(Exception) as exc:
             with mmap.mmap(-1, 10) as m:
-                raise IOError
-        self.assertIsInstance(exc.exception, IOError,
+                raise OSError
+        self.assertIsInstance(exc.exception, OSError,
                               "wrong exception raised in context manager")
         self.assertTrue(m.closed, "context manager failed")
 
@@ -709,7 +709,7 @@ class LargeMmapTests(unittest.TestCase):
             f.seek(num_zeroes)
             f.write(tail)
             f.flush()
-        except (IOError, OverflowError):
+        except (OSError, OverflowError):
             f.close()
             raise unittest.SkipTest("filesystem does not have largefile support")
         return f
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
index 9c7a202..9ec0be2 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -2019,7 +2019,7 @@ class _TestManagerRestart(BaseTestCase):
             address=addr, authkey=authkey, serializer=SERIALIZER)
         try:
             manager.start()
-        except IOError as e:
+        except OSError as e:
             if e.errno != errno.EADDRINUSE:
                 raise
             # Retry after some time, in case the old socket was lingering
@@ -2132,9 +2132,9 @@ class _TestConnection(BaseTestCase):
             self.assertEqual(reader.writable, False)
             self.assertEqual(writer.readable, False)
             self.assertEqual(writer.writable, True)
-            self.assertRaises(IOError, reader.send, 2)
-            self.assertRaises(IOError, writer.recv)
-            self.assertRaises(IOError, writer.poll)
+            self.assertRaises(OSError, reader.send, 2)
+            self.assertRaises(OSError, writer.recv)
+            self.assertRaises(OSError, writer.poll)
 
     def test_spawn_close(self):
         # We test that a pipe connection can be closed by parent
@@ -2296,8 +2296,8 @@ class _TestConnection(BaseTestCase):
         if self.TYPE == 'processes':
             self.assertTrue(a.closed)
             self.assertTrue(b.closed)
-            self.assertRaises(IOError, a.recv)
-            self.assertRaises(IOError, b.recv)
+            self.assertRaises(OSError, a.recv)
+            self.assertRaises(OSError, b.recv)
 
 class _TestListener(BaseTestCase):
 
@@ -2318,7 +2318,7 @@ class _TestListener(BaseTestCase):
                     self.assertEqual(d.recv(), 1729)
 
         if self.TYPE == 'processes':
-            self.assertRaises(IOError, l.accept)
+            self.assertRaises(OSError, l.accept)
 
 class _TestListenerClient(BaseTestCase):
 
@@ -2866,12 +2866,12 @@ class TestInvalidHandle(unittest.TestCase):
     def test_invalid_handles(self):
         conn = multiprocessing.connection.Connection(44977608)
         try:
-            self.assertRaises((ValueError, IOError), conn.poll)
+            self.assertRaises((ValueError, OSError), conn.poll)
         finally:
             # Hack private attribute _handle to avoid printing an error
             # in conn.__del__
             conn._handle = None
-        self.assertRaises((ValueError, IOError),
+        self.assertRaises((ValueError, OSError),
                           multiprocessing.connection.Connection, -1)
 
 #
diff --git a/Lib/test/test_normalization.py b/Lib/test/test_normalization.py
index e3e2560..db28e1a 100644
--- a/Lib/test/test_normalization.py
+++ b/Lib/test/test_normalization.py
@@ -43,7 +43,7 @@ class NormalizationTest(unittest.TestCase):
         try:
             testdata = open_urlresource(TESTDATAURL, encoding="utf-8",
                                         check=check_version)
-        except (IOError, HTTPException):
+        except (OSError, HTTPException):
             self.skipTest("Could not retrieve " + TESTDATAURL)
         self.addCleanup(testdata.close)
         for line in testdata:
diff --git a/Lib/test/test_ossaudiodev.py b/Lib/test/test_ossaudiodev.py
index 3908a05..c9e2a24 100644
--- a/Lib/test/test_ossaudiodev.py
+++ b/Lib/test/test_ossaudiodev.py
@@ -44,7 +44,7 @@ class OSSAudioDevTests(unittest.TestCase):
     def play_sound_file(self, data, rate, ssize, nchannels):
         try:
             dsp = ossaudiodev.open('w')
-        except IOError as msg:
+        except OSError as msg:
             if msg.args[0] in (errno.EACCES, errno.ENOENT,
                                errno.ENODEV, errno.EBUSY):
                 raise unittest.SkipTest(msg)
@@ -190,7 +190,7 @@ class OSSAudioDevTests(unittest.TestCase):
 def test_main():
     try:
         dsp = ossaudiodev.open('w')
-    except (ossaudiodev.error, IOError) as msg:
+    except (ossaudiodev.error, OSError) as msg:
         if msg.args[0] in (errno.EACCES, errno.ENOENT,
                            errno.ENODEV, errno.EBUSY):
             raise unittest.SkipTest(msg)
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index f4e8aba..fba5078 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -550,7 +550,7 @@ class PosixTester(unittest.TestCase):
             self.assertEqual(st.st_flags | stat.UF_IMMUTABLE, new_st.st_flags)
             try:
                 fd = open(target_file, 'w+')
-            except IOError as e:
+            except OSError as e:
                 self.assertEqual(e.errno, errno.EPERM)
         finally:
             posix.chflags(target_file, st.st_flags)
diff --git a/Lib/test/test_resource.py b/Lib/test/test_resource.py
index 3c9b620..0240c69 100644
--- a/Lib/test/test_resource.py
+++ b/Lib/test/test_resource.py
@@ -61,7 +61,7 @@ class ResourceTest(unittest.TestCase):
                         for i in range(5):
                             time.sleep(.1)
                             f.flush()
-                    except IOError:
+                    except OSError:
                         if not limit_set:
                             raise
                     if limit_set:
diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
index ad62280..f7b14b8 100644
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -1515,7 +1515,7 @@ class TestCopyFile(unittest.TestCase):
             self._exited_with = exc_type, exc_val, exc_tb
             if self._raise_in_exit:
                 self._raised = True
-                raise IOError("Cannot close")
+                raise OSError("Cannot close")
             return self._suppress_at_exit
 
     def tearDown(self):
@@ -1529,12 +1529,12 @@ class TestCopyFile(unittest.TestCase):
     def test_w_source_open_fails(self):
         def _open(filename, mode='r'):
             if filename == 'srcfile':
-                raise IOError('Cannot open "srcfile"')
+                raise OSError('Cannot open "srcfile"')
             assert 0  # shouldn't reach here.
 
         self._set_shutil_open(_open)
 
-        self.assertRaises(IOError, shutil.copyfile, 'srcfile', 'destfile')
+        self.assertRaises(OSError, shutil.copyfile, 'srcfile', 'destfile')
 
     def test_w_dest_open_fails(self):
 
@@ -1544,14 +1544,14 @@ class TestCopyFile(unittest.TestCase):
             if filename == 'srcfile':
                 return srcfile
             if filename == 'destfile':
-                raise IOError('Cannot open "destfile"')
+                raise OSError('Cannot open "destfile"')
             assert 0  # shouldn't reach here.
 
         self._set_shutil_open(_open)
 
         shutil.copyfile('srcfile', 'destfile')
         self.assertTrue(srcfile._entered)
-        self.assertTrue(srcfile._exited_with[0] is IOError)
+        self.assertTrue(srcfile._exited_with[0] is OSError)
         self.assertEqual(srcfile._exited_with[1].args,
                          ('Cannot open "destfile"',))
 
@@ -1573,7 +1573,7 @@ class TestCopyFile(unittest.TestCase):
         self.assertTrue(srcfile._entered)
         self.assertTrue(destfile._entered)
         self.assertTrue(destfile._raised)
-        self.assertTrue(srcfile._exited_with[0] is IOError)
+        self.assertTrue(srcfile._exited_with[0] is OSError)
         self.assertEqual(srcfile._exited_with[1].args,
                          ('Cannot close',))
 
@@ -1591,7 +1591,7 @@ class TestCopyFile(unittest.TestCase):
 
         self._set_shutil_open(_open)
 
-        self.assertRaises(IOError,
+        self.assertRaises(OSError,
                           shutil.copyfile, 'srcfile', 'destfile')
         self.assertTrue(srcfile._entered)
         self.assertTrue(destfile._entered)
diff --git a/Lib/test/test_smtplib.py b/Lib/test/test_smtplib.py
index e475076..1509a11 100644
--- a/Lib/test/test_smtplib.py
+++ b/Lib/test/test_smtplib.py
@@ -222,7 +222,7 @@ class DebuggingServerTests(unittest.TestCase):
             self.assertEqual(smtp.source_address, ('127.0.0.1', port))
             self.assertEqual(smtp.local_hostname, 'localhost')
             smtp.quit()
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.EADDRINUSE:
                 self.skipTest("couldn't bind to port %d" % port)
             raise
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index e5d9dbc..be9206e 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -3723,7 +3723,7 @@ class FileObjectClassTestCase(SocketConnectedTest):
         # First read raises a timeout
         self.assertRaises(socket.timeout, self.read_file.read, 1)
         # Second read is disallowed
-        with self.assertRaises(IOError) as ctx:
+        with self.assertRaises(OSError) as ctx:
             self.read_file.read(1)
         self.assertIn("cannot read from timed out object", str(ctx.exception))
 
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
index aa63ee6..b3b878d 100644
--- a/Lib/test/test_ssl.py
+++ b/Lib/test/test_ssl.py
@@ -246,15 +246,15 @@ class BasicSocketTests(unittest.TestCase):
         s = ssl.wrap_socket(sock, server_side=True, certfile=CERTFILE)
         self.assertRaisesRegex(ValueError, "can't connect in server-side mode",
                                 s.connect, (HOST, 8080))
-        with self.assertRaises(IOError) as cm:
+        with self.assertRaises(OSError) as cm:
             with socket.socket() as sock:
                 ssl.wrap_socket(sock, certfile=WRONGCERT)
         self.assertEqual(cm.exception.errno, errno.ENOENT)
-        with self.assertRaises(IOError) as cm:
+        with self.assertRaises(OSError) as cm:
             with socket.socket() as sock:
                 ssl.wrap_socket(sock, certfile=CERTFILE, keyfile=WRONGCERT)
         self.assertEqual(cm.exception.errno, errno.ENOENT)
-        with self.assertRaises(IOError) as cm:
+        with self.assertRaises(OSError) as cm:
             with socket.socket() as sock:
                 ssl.wrap_socket(sock, certfile=WRONGCERT, keyfile=WRONGCERT)
         self.assertEqual(cm.exception.errno, errno.ENOENT)
@@ -442,7 +442,7 @@ class ContextTests(unittest.TestCase):
         ctx.load_cert_chain(CERTFILE)
         ctx.load_cert_chain(CERTFILE, keyfile=CERTFILE)
         self.assertRaises(TypeError, ctx.load_cert_chain, keyfile=CERTFILE)
-        with self.assertRaises(IOError) as cm:
+        with self.assertRaises(OSError) as cm:
             ctx.load_cert_chain(WRONGCERT)
         self.assertEqual(cm.exception.errno, errno.ENOENT)
         with self.assertRaisesRegex(ssl.SSLError, "PEM lib"):
@@ -527,7 +527,7 @@ class ContextTests(unittest.TestCase):
         ctx.load_verify_locations(cafile=BYTES_CERTFILE, capath=None)
         self.assertRaises(TypeError, ctx.load_verify_locations)
         self.assertRaises(TypeError, ctx.load_verify_locations, None, None)
-        with self.assertRaises(IOError) as cm:
+        with self.assertRaises(OSError) as cm:
             ctx.load_verify_locations(WRONGCERT)
         self.assertEqual(cm.exception.errno, errno.ENOENT)
         with self.assertRaisesRegex(ssl.SSLError, "PEM lib"):
@@ -1229,11 +1229,11 @@ else:
             except OSError as x:
                 if support.verbose:
                     sys.stdout.write("\nOSError is %s\n" % x.args[1])
-            except IOError as x:
+            except OSError as x:
                 if x.errno != errno.ENOENT:
                     raise
                 if support.verbose:
-                    sys.stdout.write("\IOError is %s\n" % str(x))
+                    sys.stdout.write("\OSError is %s\n" % str(x))
             else:
                 raise AssertionError("Use of invalid cert should have failed!")
 
@@ -1387,7 +1387,7 @@ else:
                                        "badkey.pem"))
 
         def test_rude_shutdown(self):
-            """A brutal shutdown of an SSL server should raise an IOError
+            """A brutal shutdown of an SSL server should raise an OSError
             in the client when attempting handshake.
             """
             listener_ready = threading.Event()
@@ -1415,7 +1415,7 @@ else:
                     listener_gone.wait()
                     try:
                         ssl_sock = ssl.wrap_socket(c)
-                    except IOError:
+                    except OSError:
                         pass
                     else:
                         self.fail('connecting to closed SSL socket should have failed')
diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
index 22374d2..eb97a2c 100644
--- a/Lib/test/test_struct.py
+++ b/Lib/test/test_struct.py
@@ -489,7 +489,7 @@ class StructTest(unittest.TestCase):
     def test_bool(self):
         class ExplodingBool(object):
             def __bool__(self):
-                raise IOError
+                raise OSError
         for prefix in tuple("<>!=")+('',):
             false = (), [], [], '', 0
             true = [1], 'test', 5, -1, 0xffffffff+1, 0xffffffff/2
@@ -520,10 +520,10 @@ class StructTest(unittest.TestCase):
 
             try:
                 struct.pack(prefix + '?', ExplodingBool())
-            except IOError:
+            except OSError:
                 pass
             else:
-                self.fail("Expected IOError: struct.pack(%r, "
+                self.fail("Expected OSError: struct.pack(%r, "
                           "ExplodingBool())" % (prefix + '?'))
 
         for c in [b'\x01', b'\x7f', b'\xff', b'\x0f', b'\xf0']:
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index 8bbf4ae..0c4328f 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -1662,20 +1662,20 @@ class ContextManagerTest(unittest.TestCase):
         self.assertTrue(tar.closed, "context manager failed")
 
     def test_closed(self):
-        # The __enter__() method is supposed to raise IOError
+        # The __enter__() method is supposed to raise OSError
         # if the TarFile object is already closed.
         tar = tarfile.open(tarname)
         tar.close()
-        with self.assertRaises(IOError):
+        with self.assertRaises(OSError):
             with tar:
                 pass
 
     def test_exception(self):
-        # Test if the IOError exception is passed through properly.
+        # Test if the OSError exception is passed through properly.
         with self.assertRaises(Exception) as exc:
             with tarfile.open(tarname) as tar:
-                raise IOError
-        self.assertIsInstance(exc.exception, IOError,
+                raise OSError
+        self.assertIsInstance(exc.exception, OSError,
                               "wrong exception raised in context manager")
         self.assertTrue(tar.closed, "context manager failed")
 
@@ -1753,7 +1753,7 @@ class GzipMiscReadTest(MiscReadTest):
     def test_non_existent_targz_file(self):
         # Test for issue11513: prevent non-existent gzipped tarfiles raising
         # multiple exceptions.
-        with self.assertRaisesRegex(IOError, "xxx") as ex:
+        with self.assertRaisesRegex(OSError, "xxx") as ex:
             tarfile.open("xxx", self.mode)
         self.assertEqual(ex.exception.errno, errno.ENOENT)
 
diff --git a/Lib/test/test_timeout.py b/Lib/test/test_timeout.py
index c3c4acf..d28d62b 100644
--- a/Lib/test/test_timeout.py
+++ b/Lib/test/test_timeout.py
@@ -194,7 +194,7 @@ class TCPTimeoutTestCase(TimeoutTestCase):
             sock.connect((whitehole))
         except socket.timeout:
             pass
-        except IOError as err:
+        except OSError as err:
             if err.errno == errno.ECONNREFUSED:
                 skip = False
         finally:
diff --git a/Lib/test/test_ucn.py b/Lib/test/test_ucn.py
index 68a3219..319c213 100644
--- a/Lib/test/test_ucn.py
+++ b/Lib/test/test_ucn.py
@@ -172,7 +172,7 @@ class UnicodeNamesTest(unittest.TestCase):
         try:
             testdata = support.open_urlresource(url, encoding="utf-8",
                                                 check=check_version)
-        except (IOError, HTTPException):
+        except (OSError, HTTPException):
             self.skipTest("Could not retrieve " + url)
         self.addCleanup(testdata.close)
         for line in testdata:
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 1e30fa6..72a0d8b 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -232,7 +232,7 @@ class urlopen_HttpTests(unittest.TestCase, FakeHTTPMixin):
         self.check_read(b"1.1")
 
     def test_read_bogus(self):
-        # urlopen() should raise IOError for many error codes.
+        # urlopen() should raise OSError for many error codes.
         self.fakehttp(b'''HTTP/1.1 401 Authentication Required
 Date: Wed, 02 Jan 2008 03:03:54 GMT
 Server: Apache/1.3.33 (Debian GNU/Linux) mod_ssl/2.8.22 OpenSSL/0.9.7e
@@ -240,12 +240,12 @@ Connection: close
 Content-Type: text/html; charset=iso-8859-1
 ''')
         try:
-            self.assertRaises(IOError, urlopen, "http://python.org/")
+            self.assertRaises(OSError, urlopen, "http://python.org/")
         finally:
             self.unfakehttp()
 
     def test_invalid_redirect(self):
-        # urlopen() should raise IOError for many error codes.
+        # urlopen() should raise OSError for many error codes.
         self.fakehttp(b'''HTTP/1.1 302 Found
 Date: Wed, 02 Jan 2008 03:03:54 GMT
 Server: Apache/1.3.33 (Debian GNU/Linux) mod_ssl/2.8.22 OpenSSL/0.9.7e
@@ -260,11 +260,11 @@ Content-Type: text/html; charset=iso-8859-1
             self.unfakehttp()
 
     def test_empty_socket(self):
-        # urlopen() raises IOError if the underlying socket does not send any
+        # urlopen() raises OSError if the underlying socket does not send any
         # data. (#1680230)
         self.fakehttp(b'')
         try:
-            self.assertRaises(IOError, urlopen, "http://something")
+            self.assertRaises(OSError, urlopen, "http://something")
         finally:
             self.unfakehttp()
 
diff --git a/Lib/test/test_urllib2_localnet.py b/Lib/test/test_urllib2_localnet.py
index 6ef4200..fb2413d 100644
--- a/Lib/test/test_urllib2_localnet.py
+++ b/Lib/test/test_urllib2_localnet.py
@@ -522,7 +522,7 @@ class TestUrlopen(unittest.TestCase):
     def test_bad_address(self):
         # Make sure proper exception is raised when connecting to a bogus
         # address.
-        self.assertRaises(IOError,
+        self.assertRaises(OSError,
                           # Given that both VeriSign and various ISPs have in
                           # the past or are presently hijacking various invalid
                           # domain name requests in an attempt to boost traffic
diff --git a/Lib/test/test_urllibnet.py b/Lib/test/test_urllibnet.py
index d3fe69d..e0782d2 100644
--- a/Lib/test/test_urllibnet.py
+++ b/Lib/test/test_urllibnet.py
@@ -121,7 +121,7 @@ class urlopenNetworkTests(unittest.TestCase):
         else:
             # This happens with some overzealous DNS providers such as OpenDNS
             self.skipTest("%r should not resolve for test to work" % bogus_domain)
-        self.assertRaises(IOError,
+        self.assertRaises(OSError,
                           # SF patch 809915:  In Sep 2003, VeriSign started
                           # highjacking invalid .com and .net addresses to
                           # boost traffic to their own site.  This test
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index ac6983f..369cb4f 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -929,7 +929,7 @@ class OtherTests(unittest.TestCase):
         try:
             with zipfile.ZipFile(TESTFN, 'a') as zf:
                 zf.writestr(filename, content)
-        except IOError:
+        except OSError:
             self.fail('Could not append data to a non-existent zip file.')
 
         self.assertTrue(os.path.exists(TESTFN))
@@ -995,7 +995,7 @@ class OtherTests(unittest.TestCase):
         chk = zipfile.is_zipfile(fp)
         self.assertTrue(chk)
 
-    def test_non_existent_file_raises_IOError(self):
+    def test_non_existent_file_raises_OSError(self):
         # make sure we don't raise an AttributeError when a partially-constructed
         # ZipFile instance is finalized; this tests for regression on SF tracker
         # bug #403871.
@@ -1007,7 +1007,7 @@ class OtherTests(unittest.TestCase):
         # it is ignored, but the user should be sufficiently annoyed by
         # the message on the output that regression will be noticed
         # quickly.
-        self.assertRaises(IOError, zipfile.ZipFile, TESTFN)
+        self.assertRaises(OSError, zipfile.ZipFile, TESTFN)
 
     def test_empty_file_raises_BadZipFile(self):
         f = open(TESTFN, 'w')
@@ -1281,7 +1281,7 @@ class OtherTests(unittest.TestCase):
     def test_open_empty_file(self):
         # Issue 1710703: Check that opening a file with less than 22 bytes
         # raises a BadZipFile exception (rather than the previously unhelpful
-        # IOError)
+        # OSError)
         f = open(TESTFN, 'w')
         f.close()
         self.assertRaises(zipfile.BadZipFile, zipfile.ZipFile, TESTFN, 'r')
diff --git a/Lib/test/test_zipimport.py b/Lib/test/test_zipimport.py
index f7cb8b9..9c3f6d4 100644
--- a/Lib/test/test_zipimport.py
+++ b/Lib/test/test_zipimport.py
@@ -459,7 +459,7 @@ class BadFileZipImportTestCase(unittest.TestCase):
 
             self.assertRaises(error, z.load_module, 'abc')
             self.assertRaises(error, z.get_code, 'abc')
-            self.assertRaises(IOError, z.get_data, 'abc')
+            self.assertRaises(OSError, z.get_data, 'abc')
             self.assertRaises(error, z.get_source, 'abc')
             self.assertRaises(error, z.is_package, 'abc')
         finally: