chore: Refactor code quality issues

kombu/transport/qpid.py

@@ -584,10 +584,7 @@ def _has_queue(self, queue, **kwargs):
         :rtype: bool
 
         """
-        if self._broker.getQueue(queue):
-            return True
-        else:
-            return False
+        return bool(self._broker.getQueue(queue))
 
     def queue_declare(self, queue, passive=False, durable=False,
                       exclusive=False, auto_delete=True, nowait=False,

kombu/utils/compat.py

@@ -130,7 +130,7 @@ def nested(*managers):  # pragma: no cover
             while exits:
                 exit = exits.pop()
                 try:
-                    if exit(*exc):
+                    if sys.exit(*exc):
                         exc = (None, None, None)
                 except:
                     exc = sys.exc_info()

t/unit/asynchronous/test_timer.py

@@ -73,7 +73,6 @@ def test_supports_Timer_interface(self):
         assert x.schedule is x
 
     def test_handle_error(self):
-        from datetime import datetime
         on_error = Mock(name='on_error')
 
         s = Timer(on_error=on_error)

t/unit/test_clocks.py

@@ -79,7 +79,7 @@ def test_order(self):
         assert a <= b
         assert b >= a
 
-        assert (timetuple(134, time(), 'A', 'obj').__lt__(tuple()) is
+        assert (timetuple(134, time(), 'A', 'obj').__lt__(()) is
                 NotImplemented)
         assert timetuple(134, t2, 'A', 'obj') > timetuple(133, t1, 'A', 'obj')
         assert timetuple(134, t1, 'B', 'obj') > timetuple(134, t1, 'A', 'obj')

t/unit/transport/test_redis.py

@@ -1043,7 +1043,6 @@ def test_get_client(self):
             assert conn.transport.channel_errors
 
     def test_check_at_least_we_try_to_connect_and_fail(self):
-        import redis
         connection = Connection('redis://localhost:65534/')
 
         with pytest.raises(redis.exceptions.ConnectionError):