Queue.Queue vs. collections.deque

Question

I need a queue which multiple threads can put stuff into, and multiple threads may read from.

Python has at least two queue classes, Queue.Queue and collections.dequ

Answer 1

Queue.Queue and collections.deque serve different purposes. Queue.Queue is intended for allowing different threads to communicate using queued messages/data, whereas collections.deque is simply intended as a datastructure. That's why Queue.Queue has methods like put_nowait(), get_nowait(), and join(), whereas collections.deque doesn't. Queue.Queue isn't intended to be used as a collection, which is why it lacks the likes of the in operator.

It boils down to this: if you have multiple threads and you want them to be able to communicate without the need for locks, you're looking for Queue.Queue; if you just want a queue or a double-ended queue as a datastructure, use collections.deque.

Finally, accessing and manipulating the internal deque of a Queue.Queue is playing with fire - you really don't want to be doing that.