Skip some more tests in the absence of threading.

Lib/test/test_logging.py

@@ -25,24 +25,17 @@ import logging
 import logging.handlers
 import logging.config
 
-import asynchat
-import asyncore
 import codecs
 import datetime
-import errno
 import pickle
 import io
 import gc
-from http.server import HTTPServer, BaseHTTPRequestHandler
 import json
 import os
 import queue
 import re
 import select
-import smtpd
 import socket
-from socketserver import (ThreadingUDPServer, DatagramRequestHandler,
-                          ThreadingTCPServer, StreamRequestHandler)
 import struct
 import sys
 import tempfile
@@ -51,11 +44,19 @@ from test.support import TestHandler, Matcher
 import textwrap
 import time
 import unittest
-from urllib.parse import urlparse, parse_qs
 import warnings
 import weakref
 try:
     import threading
+    # The following imports are needed only for tests which
+    import asynchat
+    import asyncore
+    import errno
+    from http.server import HTTPServer, BaseHTTPRequestHandler
+    import smtpd
+    from urllib.parse import urlparse, parse_qs
+    from socketserver import (ThreadingUDPServer, DatagramRequestHandler,
+                              ThreadingTCPServer, StreamRequestHandler)
 except ImportError:
     threading = None
 try:
@@ -611,6 +612,7 @@ class StreamHandlerTest(BaseTest):
 # -- The following section could be moved into a server_helper.py module
 # -- if it proves to be of wider utility than just test_logging
 
+if threading:
     class TestSMTPChannel(smtpd.SMTPChannel):
         """
         This derived class has had to be created because smtpd does not
@@ -889,6 +891,7 @@ class TestUDPServer(ControlMixin, ThreadingUDPServer):
 
 # - end of server_helper section
 
+@unittest.skipUnless(threading, 'Threading required for this test.')
 class SMTPHandlerTest(BaseTest):
     def test_basic(self):
         sockmap = {}