examining items in a python Queue

Question

Is it possible to examine items in a Queue in Python without calling .get()? As per the docs, indexing is not allowed in Queue. I need to check if the item at the head of the queue satisfies some condition and if it does, remove it from the queue. Similarly I need to check if any other item in the queue satisfy the similar condition and remove it.

Am I using the wrong data structure here?

Answer 1

queue_object.queue will return copy of your queue in a deque object which you can then use the slices of. It is of course, not syncronized with the original queue, but will allow you to peek at the queue at the time of the copy.

There's a good rationalization for why you wouldn't want to do this explained in detail in this thread comp.lang.python - Queue peek?. But if you're just trying to understand how Queue works, this is one simple way.

import Queue
q = Queue.Queue()
q.push(1)
q.put('foo')
q.put('bar')
d = q.queue
print(d)
deque(['foo', 'bar'])
print(d[0])
'foo'