Remove unused or redundant imports in concurrent.futures and multiprocessing.

Lib/concurrent/futures/_base.py

@@ -4,7 +4,6 @@
 __author__ = 'Brian Quinlan (brian@sweetapp.com)'
 
 import collections
-import functools
 import logging
 import threading
 import time

Lib/concurrent/futures/process.py

@@ -221,7 +221,7 @@ def _queue_management_worker(executor_reference,
         assert sentinels
         try:
             result_item = result_queue.get(sentinels=sentinels)
-        except SentinelReady as e:
+        except SentinelReady:
             # Mark the process pool broken so that submits fail right now.
             executor = executor_reference()
             if executor is not None:
@@ -291,7 +291,6 @@ def _check_system_limits():
             raise NotImplementedError(_system_limited)
     _system_limits_checked = True
     try:
-        import os
         nsems_max = os.sysconf("SC_SEM_NSEMS_MAX")
     except (AttributeError, ValueError):
         # sysconf not available or setting not available

Lib/concurrent/futures/thread.py

@@ -74,7 +74,7 @@ def _worker(executor_reference, work_queue):
                 work_queue.put(None)
                 return
             del executor
-    except BaseException as e:
+    except BaseException:
         _base.LOGGER.critical('Exception in worker', exc_info=True)
 
 class ThreadPoolExecutor(_base.Executor):