diff --git a/Lib/concurrent/futures/_base.py b/Lib/concurrent/futures/_base.py
index 6cfded3..3b097b5 100644
--- a/Lib/concurrent/futures/_base.py
+++ b/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
diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py
index 9b2e0f3..0575146 100644
--- a/Lib/concurrent/futures/process.py
+++ b/Lib/concurrent/futures/process.py
@@ -221,7 +221,7 @@
         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 @@
             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
diff --git a/Lib/concurrent/futures/thread.py b/Lib/concurrent/futures/thread.py
index fbac088..95bb682 100644
--- a/Lib/concurrent/futures/thread.py
+++ b/Lib/concurrent/futures/thread.py
@@ -74,7 +74,7 @@
                 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):