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

(seems I don't have reputation to comment...) You need to be careful which methods of the deque you use from different threads.

deque.get() appears to be threadsafe, but I have found that doing

for item in a_deque:
   process(item)

can fail if another thread is adding items at the same time. I got an RuntimeException that complained "deque mutated during iteration".

Check collectionsmodule.c to see which operations are affected by this