Issue #18200: Update the stdlib (except tests) to use

ModuleNotFoundError.

Lib/_dummy_thread.py

@@ -7,7 +7,7 @@ Suggested usage is::
 
     try:
         import _thread
-    except ImportError:
+    except ModuleNotFoundError:
         import _dummy_thread as _thread
 
 """

Lib/_osx_support.py

@@ -62,7 +62,7 @@ def _read_output(commandstring):
     try:
         import tempfile
         fp = tempfile.NamedTemporaryFile()
-    except ImportError:
+    except ModuleNotFoundError:
         fp = open("/tmp/_osx_support.%s"%(
             os.getpid(),), "w+b")
 

Lib/_pyio.py

@@ -9,7 +9,7 @@ import errno
 # Import _thread instead of threading to reduce startup cost
 try:
     from _thread import allocate_lock as Lock
-except ImportError:
+except ModuleNotFoundError:
     from _dummy_thread import allocate_lock as Lock
 
 import io
@@ -1486,7 +1486,7 @@ class TextIOWrapper(TextIOBase):
             if encoding is None:
                 try:
                     import locale
-                except ImportError:
+                except ModuleNotFoundError:
                     # Importing locale may fail if Python is being built
                     encoding = "ascii"
                 else:

Lib/_strptime.py

@@ -21,7 +21,7 @@ from datetime import (date as datetime_date,
                       timezone as datetime_timezone)
 try:
     from _thread import allocate_lock as _thread_allocate_lock
-except ImportError:
+except ModuleNotFoundError:
     from _dummy_thread import allocate_lock as _thread_allocate_lock
 
 __all__ = []

Lib/bisect.py

@@ -88,5 +88,5 @@ def bisect_left(a, x, lo=0, hi=None):
 # Overwrite above definitions with a fast C implementation
 try:
     from _bisect import *
-except ImportError:
+except ModuleNotFoundError:
     pass

Lib/bz2.py

@@ -14,7 +14,7 @@ import warnings
 
 try:
     from threading import RLock
-except ImportError:
+except ModuleNotFoundError:
     from dummy_threading import RLock
 
 from _bz2 import BZ2Compressor, BZ2Decompressor

Lib/cmd.py

@@ -109,7 +109,7 @@ class Cmd:
                 self.old_completer = readline.get_completer()
                 readline.set_completer(self.complete)
                 readline.parse_and_bind(self.completekey+": complete")
-            except ImportError:
+            except ModuleNotFoundError:
                 pass
         try:
             if intro is not None:
@@ -143,7 +143,7 @@ class Cmd:
                 try:
                     import readline
                     readline.set_completer(self.old_completer)
-                except ImportError:
+                except ModuleNotFoundError:
                     pass
 
 

Lib/code.py

@@ -293,7 +293,7 @@ def interact(banner=None, readfunc=None, local=None):
     else:
         try:
             import readline
-        except ImportError:
+        except ModuleNotFoundError:
             pass
     console.interact(banner)
 

Lib/collections/__init__.py

@@ -395,7 +395,7 @@ def _count_elements(mapping, iterable):
 
 try:                                    # Load C helper function if available
     from _collections import _count_elements
-except ImportError:
+except ModuleNotFoundError:
     pass
 
 class Counter(dict):

Lib/copy.py

@@ -59,7 +59,7 @@ error = Error   # backward compatibility
 
 try:
     from org.python.core import PyStringMap
-except ImportError:
+except ModuleNotFoundError:
     PyStringMap = None
 
 __all__ = ["Error", "copy", "deepcopy"]

Lib/datetime.py

@@ -2116,7 +2116,7 @@ _EPOCH = datetime(1970, 1, 1, tzinfo=timezone.utc)
 
 try:
     from _datetime import *
-except ImportError:
+except ModuleNotFoundError:
     pass
 else:
     # Clean up unused names

Lib/decimal.py

@@ -149,7 +149,7 @@ import sys
 try:
     from collections import namedtuple as _namedtuple
     DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent')
-except ImportError:
+except ModuleNotFoundError:
     DecimalTuple = lambda *args: args
 
 # Rounding
@@ -430,7 +430,7 @@ _rounding_modes = (ROUND_DOWN, ROUND_HALF_UP, ROUND_HALF_EVEN, ROUND_CEILING,
 
 try:
     import threading
-except ImportError:
+except ModuleNotFoundError:
     # Python was compiled without threads; create a mock object instead
     class MockThreading(object):
         def local(self, sys=sys):
@@ -6147,7 +6147,7 @@ del re
 # don't care too much if locale isn't present.
 try:
     import locale as _locale
-except ImportError:
+except ModuleNotFoundError:
     pass
 
 def _parse_format_specifier(format_spec, _localeconv=None):
@@ -6391,7 +6391,7 @@ del sys
 
 try:
     import _decimal
-except ImportError:
+except ModuleNotFoundError:
     pass
 else:
     s1 = set(dir())

Lib/distutils/archive_util.py

@@ -9,7 +9,7 @@ import sys
 
 try:
     import zipfile
-except ImportError:
+except ModuleNotFoundError:
     zipfile = None
 
 

Lib/distutils/ccompiler.py

@@ -3,7 +3,7 @@
 Contains CCompiler, an abstract base class that defines the interface
 for the Distutils compiler abstraction model."""
 
-import sys, os, re
+import importlib, sys, os, re
 from distutils.errors import *
 from distutils.spawn import spawn
 from distutils.file_util import move_file
@@ -1013,10 +1013,9 @@ def new_compiler(plat=None, compiler=None, verbose=0, dry_run=0, force=0):
 
     try:
         module_name = "distutils." + module_name
-        __import__ (module_name)
-        module = sys.modules[module_name]
+        module = importlib.import_module(module_name)
         klass = vars(module)[class_name]
-    except ImportError:
+    except ModuleNotFoundError:
         raise DistutilsModuleError(
               "can't compile C/C++ code: unable to load module '%s'" % \
               module_name)

Lib/distutils/dist.py

@@ -4,11 +4,11 @@ Provides the Distribution class, which represents the module distribution
 being built/installed/distributed.
 """
 
-import sys, os, re
+import importlib, sys, os, re
 
 try:
     import warnings
-except ImportError:
+except ModuleNotFoundError:
     warnings = None
 
 from distutils.errors import *
@@ -788,9 +788,8 @@ Common commands: (see '--help-commands' for more)
             klass_name = command
 
             try:
-                __import__ (module_name)
-                module = sys.modules[module_name]
-            except ImportError:
+                module = importlib.import_module(module_name)
+            except ModuleNotFoundError:
                 continue
 
             try:

Lib/distutils/msvccompiler.py

@@ -28,7 +28,7 @@ try:
     RegEnumValue = winreg.EnumValue
     RegError = winreg.error
 
-except ImportError:
+except ModuleNotFoundError:
     try:
         import win32api
         import win32con
@@ -39,7 +39,7 @@ except ImportError:
         RegEnumKey = win32api.RegEnumKey
         RegEnumValue = win32api.RegEnumValue
         RegError = win32api.error
-    except ImportError:
+    except ModuleNotFoundError:
         log.info("Warning: Can't read registry to find the "
                  "necessary compiler setting\n"
                  "Make sure that Python modules winreg, "

Lib/distutils/util.py

@@ -388,7 +388,7 @@ def byte_compile (py_files,
         try:
             from tempfile import mkstemp
             (script_fd, script_name) = mkstemp(".py")
-        except ImportError:
+        except ModuleNotFoundError:
             from tempfile import mktemp
             (script_fd, script_name) = None, mktemp(".py")
         log.info("writing byte-compilation script '%s'", script_name)

Lib/encodings/__init__.py

@@ -29,11 +29,11 @@ Written by Marc-Andre Lemburg (mal@lemburg.com).
 """#"
 
 import codecs
+import importlib
 from . import aliases
 
 _cache = {}
 _unknown = '--unknown--'
-_import_tail = ['*']
 _aliases = aliases.aliases
 
 class CodecRegistryError(LookupError, SystemError):
@@ -94,9 +94,8 @@ def search_function(encoding):
         try:
             # Import is absolute to prevent the possibly malicious import of a
             # module with side-effects that is not in the 'encodings' package.
-            mod = __import__('encodings.' + modname, fromlist=_import_tail,
-                             level=0)
-        except ImportError:
+            mod = importlib.import_module('encodings.' + modname)
+        except ModuleNotFoundError:
             pass
         else:
             break

Lib/ftplib.py

@@ -667,7 +667,7 @@ class FTP:
 
 try:
     import ssl
-except ImportError:
+except ModuleNotFoundError:
     _SSLSocket = None
 else:
     _SSLSocket = ssl.SSLSocket

Lib/functools.py

@@ -15,7 +15,7 @@ __all__ = ['update_wrapper', 'wraps', 'WRAPPER_ASSIGNMENTS', 'WRAPPER_UPDATES',
 
 try:
     from _functools import reduce
-except ImportError:
+except ModuleNotFoundError:
     pass
 from abc import get_cache_token
 from collections import namedtuple
@@ -143,7 +143,7 @@ def cmp_to_key(mycmp):
 
 try:
     from _functools import cmp_to_key
-except ImportError:
+except ModuleNotFoundError:
     pass
 
 
@@ -166,7 +166,7 @@ def partial(func, *args, **keywords):
 
 try:
     from _functools import partial
-except ImportError:
+except ModuleNotFoundError:
     pass
 
 

Lib/getopt.py

@@ -36,7 +36,7 @@ __all__ = ["GetoptError","error","getopt","gnu_getopt"]
 import os
 try:
     from gettext import gettext as _
-except ImportError:
+except ModuleNotFoundError:
     # Bootstrapping Python: gettext's dependencies not built yet
     def _(s): return s
 

Lib/getpass.py

@@ -164,7 +164,7 @@ try:
 except (ImportError, AttributeError):
     try:
         import msvcrt
-    except ImportError:
+    except ModuleNotFoundError:
         getpass = fallback_getpass
     else:
         getpass = win_getpass

Lib/hashlib.py

@@ -98,7 +98,7 @@ def __get_builtin_constructor(name):
                 return _sha3.sha3_384
             elif bs == '512':
                 return _sha3.sha3_512
-    except ImportError:
+    except ModuleNotFoundError:
         pass  # no extension module, this hash is unsupported.
 
     raise ValueError('unsupported hash type ' + name)
@@ -143,7 +143,7 @@ try:
     __get_hash = __get_openssl_constructor
     algorithms_available = algorithms_available.union(
             _hashlib.openssl_md_meth_names)
-except ImportError:
+except ModuleNotFoundError:
     new = __py_new
     __get_hash = __get_builtin_constructor
 

Lib/heapq.py

@@ -343,7 +343,7 @@ def _siftup_max(heap, pos):
 # If available, use C implementation
 try:
     from _heapq import *
-except ImportError:
+except ModuleNotFoundError:
     pass
 
 def merge(*iterables):

Lib/http/client.py

@@ -1156,7 +1156,7 @@ class HTTPConnection:
 
 try:
     import ssl
-except ImportError:
+except ModuleNotFoundError:
     pass
 else:
     class HTTPSConnection(HTTPConnection):

Lib/http/cookiejar.py

@@ -35,7 +35,7 @@ import time
 import urllib.parse, urllib.request
 try:
     import threading as _threading
-except ImportError:
+except ModuleNotFoundError:
     import dummy_threading as _threading
 import http.client  # only for the default HTTP port
 from calendar import timegm

Lib/http/server.py

@@ -904,7 +904,7 @@ def nobody_uid():
         return nobody
     try:
         import pwd
-    except ImportError:
+    except ModuleNotFoundError:
         return -1
     try:
         nobody = pwd.getpwnam('nobody')[2]

Lib/imaplib.py

@@ -29,7 +29,7 @@ from io import DEFAULT_BUFFER_SIZE
 try:
     import ssl
     HAVE_SSL = True
-except ImportError:
+except ModuleNotFoundError:
     HAVE_SSL = False
 
 __all__ = ["IMAP4", "IMAP4_stream", "Internaldate2tuple",

Lib/imp.py

@@ -12,7 +12,7 @@ from _imp import (lock_held, acquire_lock, release_lock,
                   _fix_co_filename)
 try:
     from _imp import load_dynamic
-except ImportError:
+except ModuleNotFoundError:
     # Platform doesn't support dynamic loading.
     load_dynamic = None
 

Lib/importlib/__init__.py

@@ -14,7 +14,7 @@ import sys
 
 try:
     import _frozen_importlib as _bootstrap
-except ImportError:
+except ModuleNotFoundError:
     from . import _bootstrap
     _bootstrap._setup(sys, _imp)
 else:

Lib/importlib/abc.py

@@ -3,7 +3,7 @@ from . import _bootstrap
 from . import machinery
 try:
     import _frozen_importlib
-except ImportError as exc:
+except ModuleNotFoundError as exc:
     if exc.name != '_frozen_importlib':
         raise
     _frozen_importlib = None

Lib/inspect.py

@@ -51,7 +51,7 @@ from collections import namedtuple, OrderedDict
 # back to hardcording so the dependency is optional
 try:
     from dis import COMPILER_FLAG_NAMES as _flag_names
-except ImportError:
+except ModuleNotFoundError:
     CO_OPTIMIZED, CO_NEWLOCALS = 0x1, 0x2
     CO_VARARGS, CO_VARKEYWORDS = 0x4, 0x8
     CO_NESTED, CO_GENERATOR, CO_NOFREE = 0x10, 0x20, 0x40

Lib/json/decoder.py

@@ -5,7 +5,7 @@ import re
 from json import scanner
 try:
     from _json import scanstring as c_scanstring
-except ImportError:
+except ModuleNotFoundError:
     c_scanstring = None
 
 __all__ = ['JSONDecoder']

Lib/json/encoder.py

@@ -4,11 +4,11 @@ import re
 
 try:
     from _json import encode_basestring_ascii as c_encode_basestring_ascii
-except ImportError:
+except ModuleNotFoundError:
     c_encode_basestring_ascii = None
 try:
     from _json import make_encoder as c_make_encoder
-except ImportError:
+except ModuleNotFoundError:
     c_make_encoder = None
 
 ESCAPE = re.compile(r'[\x00-\x1f\\"\b\f\n\r\t]')

Lib/json/scanner.py

@@ -3,7 +3,7 @@
 import re
 try:
     from _json import make_scanner as c_make_scanner
-except ImportError:
+except ModuleNotFoundError:
     c_make_scanner = None
 
 __all__ = ['make_scanner']

Lib/lib2to3/refactor.py

@@ -706,7 +706,7 @@ class MultiprocessRefactoringTool(RefactoringTool):
                 items, write, doctests_only)
         try:
             import multiprocessing
-        except ImportError:
+        except ModuleNotFoundError:
             raise MultiprocessingUnsupported
         if self.queue is not None:
             raise RuntimeError("already doing multiple processes")

Lib/locale.py

@@ -47,7 +47,7 @@ try:
 
     from _locale import *
 
-except ImportError:
+except ModuleNotFoundError:
 
     # Locale emulation
 

Lib/logging/__init__.py

@@ -37,7 +37,7 @@ __all__ = ['BASIC_FORMAT', 'BufferingFormatter', 'CRITICAL', 'DEBUG', 'ERROR',
 
 try:
     import threading
-except ImportError: #pragma: no cover
+except ModuleNotFoundError: #pragma: no cover
     threading = None
 
 __author__  = "Vinay Sajip <vinay_sajip@red-dove.com>"

Lib/logging/config.py

@@ -30,7 +30,7 @@ import io
 try:
     import _thread as thread
     import threading
-except ImportError: #pragma: no cover
+except ModuleNotFoundError: #pragma: no cover
     thread = None
 
 from socketserver import ThreadingTCPServer, StreamRequestHandler

Lib/logging/handlers.py

@@ -29,7 +29,7 @@ from stat import ST_DEV, ST_INO, ST_MTIME
 import queue
 try:
     import threading
-except ImportError: #pragma: no cover
+except ModuleNotFoundError: #pragma: no cover
     threading = None
 
 #
@@ -995,7 +995,7 @@ class NTEventLogHandler(logging.Handler):
                 logging.ERROR   : win32evtlog.EVENTLOG_ERROR_TYPE,
                 logging.CRITICAL: win32evtlog.EVENTLOG_ERROR_TYPE,
          }
-        except ImportError:
+        except ModuleNotFoundError:
             print("The Python Win32 extensions for NT (service, event "\
                         "logging) appear not to be available.")
             self._welu = None

Lib/macpath.py

@@ -187,7 +187,7 @@ def realpath(path):
     path = abspath(path)
     try:
         import Carbon.File
-    except ImportError:
+    except ModuleNotFoundError:
         return path
     if not path:
         return path

Lib/mailbox.py

@@ -23,7 +23,7 @@ import io
 import contextlib
 try:
     import fcntl
-except ImportError:
+except ModuleNotFoundError:
     fcntl = None
 
 __all__ = [ 'Mailbox', 'Maildir', 'mbox', 'MH', 'Babyl', 'MMDF',

Lib/mimetypes.py

@@ -29,7 +29,7 @@ import posixpath
 import urllib.parse
 try:
     import winreg as _winreg
-except ImportError:
+except ModuleNotFoundError:
     _winreg = None
 
 __all__ = [

Lib/multiprocessing/connection.py

@@ -27,7 +27,7 @@ from multiprocessing.forking import ForkingPickler
 try:
     import _winapi
     from _winapi import WAIT_OBJECT_0, WAIT_TIMEOUT, INFINITE
-except ImportError:
+except ModuleNotFoundError:
     if sys.platform == 'win32':
         raise
     _winapi = None

Lib/multiprocessing/forking.py

@@ -73,7 +73,7 @@ ForkingPickler.register(type(int.__add__), _reduce_method_descriptor)
 
 try:
     from functools import partial
-except ImportError:
+except ModuleNotFoundError:
     pass
 else:
     def _reduce_partial(p):

Lib/nntplib.py

@@ -71,7 +71,7 @@ import warnings
 
 try:
     import ssl
-except ImportError:
+except ModuleNotFoundError:
     _have_ssl = False
 else:
     _have_ssl = True

Lib/ntpath.py

@@ -566,7 +566,7 @@ def normpath(path):
 try:
     from nt import _getfullpathname
 
-except ImportError: # not running on Windows - mock up something sensible
+except ModuleNotFoundError: # not running on Windows - mock up something sensible
     def abspath(path):
         """Return the absolute version of a path."""
         if not isabs(path):
@@ -659,6 +659,6 @@ try:
     # This is overkill on Windows - just pass the path to GetFileAttributes
     # and check the attribute from there.
     from nt import _isdir as isdir
-except ImportError:
+except ModuleNotFoundError:
     # Use genericpath.isdir as imported above.
     pass

Lib/operator.py

@@ -360,7 +360,7 @@ def ixor(a, b):
 
 try:
     from _operator import *
-except ImportError:
+except ModuleNotFoundError:
     pass
 else:
     from _operator import __doc__

Lib/optparse.py

@@ -87,7 +87,7 @@ def _repr(self):
 
 try:
     from gettext import gettext, ngettext
-except ImportError:
+except ModuleNotFoundError:
     def gettext(message):
         return message
 

Lib/os.py

@@ -52,13 +52,13 @@ if 'posix' in _names:
     try:
         from posix import _exit
         __all__.append('_exit')
-    except ImportError:
+    except ModuleNotFoundError:
         pass
     import posixpath as path
 
     try:
         from posix import _have_functions
-    except ImportError:
+    except ModuleNotFoundError:
         pass
 
 elif 'nt' in _names:
@@ -68,7 +68,7 @@ elif 'nt' in _names:
     try:
         from nt import _exit
         __all__.append('_exit')
-    except ImportError:
+    except ModuleNotFoundError:
         pass
     import ntpath as path
 
@@ -78,7 +78,7 @@ elif 'nt' in _names:
 
     try:
         from nt import _have_functions
-    except ImportError:
+    except ModuleNotFoundError:
         pass
 
 elif 'ce' in _names:
@@ -88,7 +88,7 @@ elif 'ce' in _names:
     try:
         from ce import _exit
         __all__.append('_exit')
-    except ImportError:
+    except ModuleNotFoundError:
         pass
     # We can use the standard Windows path.
     import ntpath as path
@@ -99,11 +99,11 @@ elif 'ce' in _names:
 
     try:
         from ce import _have_functions
-    except ImportError:
+    except ModuleNotFoundError:
         pass
 
 else:
-    raise ImportError('no os specific module found')
+    raise ModuleNotFoundError('no os specific module found')
 
 sys.modules['os.path'] = path
 from os.path import (curdir, pardir, sep, pathsep, defpath, extsep, altsep,

Lib/pdb.py

@@ -158,7 +158,7 @@ class Pdb(bdb.Bdb, cmd.Cmd):
             import readline
             # remove some common file name delimiters
             readline.set_completer_delims(' \t\n`@#$%^&*()=+[{]}\\|;:\'",<>?')
-        except ImportError:
+        except ModuleNotFoundError:
             pass
         self.allow_kbdint = False
         self.nosigint = nosigint

Lib/pickle.py

@@ -90,7 +90,7 @@ class _Stop(Exception):
 # Jython has PyStringMap; it's a dict subclass with string keys
 try:
     from org.python.core import PyStringMap
-except ImportError:
+except ModuleNotFoundError:
     PyStringMap = None
 
 # Pickle opcodes.  See pickletools.py for extensive docs.  The listing
@@ -1296,7 +1296,7 @@ def loads(s, *, fix_imports=True, encoding="ASCII", errors="strict"):
 # Use the faster _pickle if possible
 try:
     from _pickle import *
-except ImportError:
+except ModuleNotFoundError:
     Pickler, Unpickler = _Pickler, _Unpickler
 
 # Doctest

Lib/platform.py

@@ -460,7 +460,7 @@ def _win32_getvalue(key,name,default=''):
     try:
         # Use win32api if available
         from win32api import RegQueryValueEx
-    except ImportError:
+    except ModuleNotFoundError:
         # On Python 2.0 and later, emulate using winreg
         import winreg
         RegQueryValueEx = winreg.QueryValueEx
@@ -503,7 +503,7 @@ def win32_ver(release='',version='',csd='',ptype=''):
              RegCloseKey, GetVersionEx
         from win32con import HKEY_LOCAL_MACHINE, VER_PLATFORM_WIN32_NT, \
              VER_PLATFORM_WIN32_WINDOWS, VER_NT_WORKSTATION
-    except ImportError:
+    except ModuleNotFoundError:
         # Emulate the win32api module using Python APIs
         try:
             sys.getwindowsversion
@@ -661,7 +661,7 @@ def _mac_ver_gestalt():
     # Check whether the version info module is available
     try:
         import _gestalt
-    except ImportError:
+    except ModuleNotFoundError:
         return None
     # Get the infos
     sysv, sysa = _mac_ver_lookup(('sysv','sysa'))
@@ -697,7 +697,7 @@ def _mac_ver_xml():
 
     try:
         import plistlib
-    except ImportError:
+    except ModuleNotFoundError:
         return None
 
     pl = plistlib.readPlist(fn)
@@ -762,7 +762,7 @@ def java_ver(release='',vendor='',vminfo=('','',''),osinfo=('','','')):
     # Import the needed APIs
     try:
         import java.lang
-    except ImportError:
+    except ModuleNotFoundError:
         return release,vendor,vminfo,osinfo
 
     vendor = _java_getprop('java.vendor', vendor)
@@ -874,7 +874,7 @@ def _node(default=''):
     """
     try:
         import socket
-    except ImportError:
+    except ModuleNotFoundError:
         # No sockets...
         return default
     try:
@@ -1138,7 +1138,7 @@ def uname():
         # Get processor information
         try:
             import vms_lib
-        except ImportError:
+        except ModuleNotFoundError:
             pass
         else:
             csid, cpu_number = vms_lib.getsyi('SYI$_CPU',0)

Lib/poplib.py

@@ -20,7 +20,7 @@ import socket
 try:
     import ssl
     HAVE_SSL = True
-except ImportError:
+except ModuleNotFoundError:
     HAVE_SSL = False
 
 __all__ = ["POP3","error_proto"]

Lib/pstats.py

@@ -528,7 +528,7 @@ if __name__ == '__main__':
     import cmd
     try:
         import readline
-    except ImportError:
+    except ModuleNotFoundError:
         pass
 
     class ProfileBrowser(cmd.Cmd):

Lib/pty.py

@@ -67,7 +67,7 @@ def slave_open(tty_name):
     result = os.open(tty_name, os.O_RDWR)
     try:
         from fcntl import ioctl, I_PUSH
-    except ImportError:
+    except ModuleNotFoundError:
         return result
     try:
         ioctl(result, I_PUSH, "ptem")

Lib/pydoc.py

@@ -1893,7 +1893,7 @@ Here is a list of available topics.  Enter any topic name to get more help.
     def showtopic(self, topic, more_xrefs=''):
         try:
             import pydoc_data.topics
-        except ImportError:
+        except ModuleNotFoundError:
             self.output.write('''
 Sorry, topic and keyword documentation is not available because the
 module "pydoc_data.topics" could not be found.
@@ -1933,7 +1933,7 @@ module "pydoc_data.topics" could not be found.
         """
         try:
             import pydoc_data.topics
-        except ImportError:
+        except ModuleNotFoundError:
             return('''
 Sorry, topic and keyword documentation is not available because the
 module "pydoc_data.topics" could not be found.

Lib/queue.py

@@ -2,13 +2,13 @@
 
 try:
     import threading
-except ImportError:
+except ModuleNotFoundError:
     import dummy_threading as threading
 from collections import deque
 from heapq import heappush, heappop
 try:
     from time import monotonic as time
-except ImportError:
+except ModuleNotFoundError:
     from time import time
 
 __all__ = ['Empty', 'Full', 'Queue', 'PriorityQueue', 'LifoQueue']

Lib/quopri.py

@@ -13,7 +13,7 @@ EMPTYSTRING = b''
 
 try:
     from binascii import a2b_qp, b2a_qp
-except ImportError:
+except ModuleNotFoundError:
     a2b_qp = None
     b2a_qp = None
 

Lib/reprlib.py

@@ -6,7 +6,7 @@ import builtins
 from itertools import islice
 try:
     from _thread import get_ident
-except ImportError:
+except ModuleNotFoundError:
     from _dummy_thread import get_ident
 
 def recursive_repr(fillvalue='...'):

Lib/rlcompleter.py

@@ -154,7 +154,7 @@ def get_class_members(klass):
 
 try:
     import readline
-except ImportError:
+except ModuleNotFoundError:
     pass
 else:
     readline.set_completer(Completer().complete)

Lib/sched.py

@@ -33,11 +33,11 @@ import heapq
 from collections import namedtuple
 try:
     import threading
-except ImportError:
+except ModuleNotFoundError:
     import dummy_threading as threading
 try:
     from time import monotonic as _time
-except ImportError:
+except ModuleNotFoundError:
     from time import time as _time
 
 __all__ = ["scheduler"]

Lib/shutil.py

@@ -17,17 +17,17 @@ try:
     import bz2
     del bz2
     _BZ2_SUPPORTED = True
-except ImportError:
+except ModuleNotFoundError:
     _BZ2_SUPPORTED = False
 
 try:
     from pwd import getpwnam
-except ImportError:
+except ModuleNotFoundError:
     getpwnam = None
 
 try:
     from grp import getgrnam
-except ImportError:
+except ModuleNotFoundError:
     getgrnam = None
 
 __all__ = ["copyfileobj", "copyfile", "copymode", "copystat", "copy", "copy2",
@@ -668,7 +668,7 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
     # command.
     try:
         import zipfile
-    except ImportError:
+    except ModuleNotFoundError:
         zipfile = None
 
     if zipfile is None:
@@ -858,7 +858,7 @@ def _unpack_zipfile(filename, extract_dir):
     """
     try:
         import zipfile
-    except ImportError:
+    except ModuleNotFoundError:
         raise ReadError('zlib not supported, cannot unpack this archive.')
 
     if not zipfile.is_zipfile(filename):

Lib/site.py

@@ -469,7 +469,7 @@ def enablerlcompleter():
         try:
             import readline
             import rlcompleter
-        except ImportError:
+        except ModuleNotFoundError:
             return
 
         # Reading the initialization (config) file may not be enough to set a
@@ -570,7 +570,7 @@ def execsitecustomize():
     """Run custom site specific code, if available."""
     try:
         import sitecustomize
-    except ImportError:
+    except ModuleNotFoundError:
         pass
     except Exception as err:
         if os.environ.get("PYTHONVERBOSE"):
@@ -586,7 +586,7 @@ def execusercustomize():
     """Run custom user specific code, if available."""
     try:
         import usercustomize
-    except ImportError:
+    except ModuleNotFoundError:
         pass
     except Exception as err:
         if os.environ.get("PYTHONVERBOSE"):

Lib/smtpd.py

@@ -846,7 +846,7 @@ if __name__ == '__main__':
     if options.setuid:
         try:
             import pwd
-        except ImportError:
+        except ModuleNotFoundError:
             print('Cannot import module "pwd"; try running with -n option.', file=sys.stderr)
             sys.exit(1)
         nobody = pwd.getpwnam('nobody')[2]

Lib/smtplib.py

@@ -171,7 +171,7 @@ def _fix_eols(data):
 
 try:
     import ssl
-except ImportError:
+except ModuleNotFoundError:
     _have_ssl = False
 else:
     _have_ssl = True

Lib/socket.py

@@ -51,7 +51,7 @@ import os, sys, io
 
 try:
     import errno
-except ImportError:
+except ModuleNotFoundError:
     errno = None
 EBADF = getattr(errno, 'EBADF', 9)
 EAGAIN = getattr(errno, 'EAGAIN', 11)

Lib/socketserver.py

@@ -136,7 +136,7 @@ import os
 import errno
 try:
     import threading
-except ImportError:
+except ModuleNotFoundError:
     import dummy_threading as threading
 
 __all__ = ["TCPServer","UDPServer","ForkingUDPServer","ForkingTCPServer",

Lib/sqlite3/test/dbapi.py

@@ -25,7 +25,7 @@ import unittest
 import sqlite3 as sqlite
 try:
     import threading
-except ImportError:
+except ModuleNotFoundError:
     threading = None
 
 from test.support import TESTFN, unlink

Lib/sqlite3/test/types.py

@@ -26,7 +26,7 @@ import unittest
 import sqlite3 as sqlite
 try:
     import zlib
-except ImportError:
+except ModuleNotFoundError:
     zlib = None
 
 

Lib/sre_compile.py

@@ -295,7 +295,7 @@ def _mk_bitmap(bits):
 def _optimize_unicode(charset, fixup):
     try:
         import array
-    except ImportError:
+    except ModuleNotFoundError:
         return charset
     charmap = [0]*65536
     negate = 0

Lib/ssl.py

@@ -127,14 +127,14 @@ _PROTOCOL_NAMES = {
 try:
     from _ssl import PROTOCOL_SSLv2
     _SSLv2_IF_EXISTS = PROTOCOL_SSLv2
-except ImportError:
+except ModuleNotFoundError:
     _SSLv2_IF_EXISTS = None
 else:
     _PROTOCOL_NAMES[PROTOCOL_SSLv2] = "SSLv2"
 
 try:
     from _ssl import PROTOCOL_TLSv1_1, PROTOCOL_TLSv1_2
-except ImportError:
+except ModuleNotFoundError:
     pass
 else:
     _PROTOCOL_NAMES[PROTOCOL_TLSv1_1] = "TLSv1.1"

Lib/subprocess.py

@@ -353,7 +353,7 @@ import warnings
 import errno
 try:
     from time import monotonic as _time
-except ImportError:
+except ModuleNotFoundError:
     from time import time as _time
 
 # Exception classes used by this module.

Lib/tarfile.py

@@ -50,7 +50,7 @@ import re
 
 try:
     import grp, pwd
-except ImportError:
+except ModuleNotFoundError:
     grp = pwd = None
 
 # os.symlink on Windows prior to 6.0 raises NotImplementedError
@@ -381,7 +381,7 @@ class _Stream:
             if comptype == "gz":
                 try:
                     import zlib
-                except ImportError:
+                except ModuleNotFoundError:
                     raise CompressionError("zlib module is not available")
                 self.zlib = zlib
                 self.crc = zlib.crc32(b"")
@@ -394,7 +394,7 @@ class _Stream:
             elif comptype == "bz2":
                 try:
                     import bz2
-                except ImportError:
+                except ModuleNotFoundError:
                     raise CompressionError("bz2 module is not available")
                 if mode == "r":
                     self.dbuf = b""
@@ -406,7 +406,7 @@ class _Stream:
             elif comptype == "xz":
                 try:
                     import lzma
-                except ImportError:
+                except ModuleNotFoundError:
                     raise CompressionError("lzma module is not available")
                 if mode == "r":
                     self.dbuf = b""
@@ -1654,7 +1654,7 @@ class TarFile(object):
 
         try:
             import bz2
-        except ImportError:
+        except ModuleNotFoundError:
             raise CompressionError("bz2 module is not available")
 
         fileobj = bz2.BZ2File(fileobj or name, mode,
@@ -1678,7 +1678,7 @@ class TarFile(object):
 
         try:
             import lzma
-        except ImportError:
+        except ModuleNotFoundError:
             raise CompressionError("lzma module is not available")
 
         fileobj = lzma.LZMAFile(fileobj or name, mode, preset=preset)

Lib/tempfile.py

@@ -36,7 +36,7 @@ from random import Random as _Random
 
 try:
     import fcntl as _fcntl
-except ImportError:
+except ModuleNotFoundError:
     def _set_cloexec(fd):
         pass
 else:
@@ -53,7 +53,7 @@ else:
 
 try:
     import _thread
-except ImportError:
+except ModuleNotFoundError:
     import _dummy_thread as _thread
 _allocate_lock = _thread.allocate_lock
 

Lib/threading.py

@@ -6,14 +6,14 @@ import _thread
 from time import sleep as _sleep
 try:
     from time import monotonic as _time
-except ImportError:
+except ModuleNotFoundError:
     from time import time as _time
 from traceback import format_exc as _format_exc
 from _weakrefset import WeakSet
 from itertools import islice as _islice
 try:
     from _collections import deque as _deque
-except ImportError:
+except ModuleNotFoundError:
     from collections import deque as _deque
 
 # Note regarding PEP 8 compliant names
@@ -922,7 +922,7 @@ _shutdown = _MainThread()._exitfunc
 
 try:
     from _thread import _local as local
-except ImportError:
+except ModuleNotFoundError:
     from _threading_local import local
 
 

Lib/trace.py

@@ -61,12 +61,12 @@ import pickle
 from warnings import warn as _warn
 try:
     from time import monotonic as _time
-except ImportError:
+except ModuleNotFoundError:
     from time import time as _time
 
 try:
     import threading
-except ImportError:
+except ModuleNotFoundError:
     _settrace = sys.settrace
 
     def _unsettrace():

Lib/urllib/request.py

@@ -110,7 +110,7 @@ from urllib.response import addinfourl, addclosehook
 # check for SSL
 try:
     import ssl
-except ImportError:
+except ModuleNotFoundError:
     _have_ssl = False
 else:
     _have_ssl = True
@@ -2512,7 +2512,7 @@ elif os.name == 'nt':
         proxies = {}
         try:
             import winreg
-        except ImportError:
+        except ModuleNotFoundError:
             # Std module, so should be around - but you never know!
             return proxies
         try:
@@ -2560,7 +2560,7 @@ elif os.name == 'nt':
     def proxy_bypass_registry(host):
         try:
             import winreg
-        except ImportError:
+        except ModuleNotFoundError:
             # Std modules, so should be around - but you never know!
             return 0
         try:

Lib/venv/__init__.py

@@ -35,7 +35,7 @@ import sys
 import sysconfig
 try:
     import threading
-except ImportError:
+except ModuleNotFoundError:
     threading = None
 
 logger = logging.getLogger(__name__)

Lib/warnings.py

@@ -144,8 +144,8 @@ def _getcategory(category):
         module = category[:i]
         klass = category[i+1:]
         try:
-            m = __import__(module, None, None, [klass])
-        except ImportError:
+            m = __import__(module, fromlist[klass])
+        except ModuleNotFoundError:
             raise _OptionError("invalid module name: %r" % (module,))
         try:
             cat = getattr(m, klass)
@@ -362,7 +362,7 @@ try:
     defaultaction = _defaultaction
     onceregistry = _onceregistry
     _warnings_defaults = True
-except ImportError:
+except ModuleNotFoundError:
     filters = []
     defaultaction = "default"
     onceregistry = {}

Lib/xml/etree/ElementTree.py

@@ -1439,13 +1439,13 @@ class XMLParser:
     def __init__(self, html=0, target=None, encoding=None):
         try:
             from xml.parsers import expat
-        except ImportError:
+        except ModuleNotFoundError:
             try:
                 import pyexpat as expat
-            except ImportError:
-                raise ImportError(
-                    "No module named expat; use SimpleXMLTreeBuilder instead"
-                    )
+            except ModuleNotFoundError:
+                raise ModuleNotFoundError(
+                    "No module named expat; use SimpleXMLTreeBuilder instead",
+                    name='expat')
         parser = expat.ParserCreate(encoding, "}")
         if target is None:
             target = TreeBuilder()

Lib/xml/sax/expatreader.py

@@ -20,7 +20,7 @@ del sys
 
 try:
     from xml.parsers import expat
-except ImportError:
+except ModuleNotFoundError:
     raise SAXReaderNotAvailable("expat not supported", None)
 else:
     if not hasattr(expat, "ParserCreate"):
@@ -30,18 +30,7 @@ from xml.sax import xmlreader, saxutils, handler
 AttributesImpl = xmlreader.AttributesImpl
 AttributesNSImpl = xmlreader.AttributesNSImpl
 
-# If we're using a sufficiently recent version of Python, we can use
-# weak references to avoid cycles between the parser and content
-# handler, otherwise we'll just have to pretend.
-try:
-    import _weakref
-except ImportError:
-    def _mkproxy(o):
-        return o
-else:
 import weakref
-    _mkproxy = weakref.proxy
-    del weakref, _weakref
 
 # --- ExpatLocator
 
@@ -52,7 +41,7 @@ class ExpatLocator(xmlreader.Locator):
     a circular reference between the parser and the content handler.
     """
     def __init__(self, parser):
-        self._ref = _mkproxy(parser)
+        self._ref = weakref.proxy(parser)
 
     def getColumnNumber(self):
         parser = self._ref

Lib/xmlrpc/client.py

@@ -139,7 +139,7 @@ import errno
 from io import BytesIO
 try:
     import gzip
-except ImportError:
+except ModuleNotFoundError:
     gzip = None #python can be built without zlib/gzip support
 
 # --------------------------------------------------------------------