In the author's separate page of implementation notes, a Queue class is created that doesn't have threading overhead. That would be great, but it uses list.pop

In the author's separate page of implementation notes, a Queue class is created that doesn't have threading overhead. That would be great, but it uses list.pop(0) which is an O(n) operation. For O(1) performance, it should use collections.deque.popleft() instead. Otherwise, the article is first-rate :-)