Is there non-synchronized queue in python

Question

I am practicing doing programming competitions using python(actually pypy3). For a problem I need to use a queue - I only need to put at one end and pop from the other. From what I found in the documentation it seems I have two options queue.Queue and queue.deque. I first tried the problem using queue.Queue, but my solution exceeded the time limit. Then I switched to queue.deque and I passed the problem(though close to the limit).

From the documentation it seems both containers are thread safe(well at least for some operations for deque) while for my situation I will never use more than one thread. Is there a simple non-synchronized queue built-in in python?

Answer 1

The deque certainly does not do synchronization; the documentation just states that the appends and pops are guaranteed to be thread-safe due to them being atomic. In CPython in particular there is no locking besides the Global Interpreter Lock. If you need a double-ended queue, or say FIFO, that is what you should use. If you need a LIFO stack, use a list. Internally the deque implementation uses a doubly-linked list of fixed-length blocks.

The queue.Queue uses a deque internally; in addition, it uses a mutex to guard those remaining operations that are not implemented atomically by deque.

Thus your problem is not the choice of deque, but quite probably some other aspect of your algorithm.