PYTHON PRIORITY QUEUE BY OBJECT KEY HOW TO

So you could also give it task strings alone, without extra priorities. Only we the users think of the pair as priority and task. It just thinks of the pair as one 'item' and it never even looks into it.

It doesn't think of the two values as priority and task. Note that you give Python's priority queue pairs of priority and task, but the queue doesn't care. Fortunately it's as simple as storing entries 'as 3-element list including the priority, an entry count, and the task'. If you want stability, you'll need to enforce it yourself. That's also why heapsort 'is not a stable sort'. And heaps don't naturally offer stability. As the documentation says, it's 'using the heapq module'. Priority queues 'are often implemented with heaps' and Python is no exception.

The expected result: QUIT goes out first, and then the rest, FIFO ordered: Build, Clean, Create, Build, Clean: > q.get() Now I'll dequeue the elements one by one.

Return cmp(self.priority, other.priority) Self.priority = 0 if self.type_ = 'QUIT' else 1 I was asked to add an example that shows that q.get() actually mess things up with the FIFO ordering, so here's an elaborate example: class Job(object):

PYTHON PRIORITY QUEUE BY OBJECT KEY HOW TO

What's the reason? how to overcome (keep the order of same prio elements)? For some reason this is not the case: > from Queue import PriorityQueueĪs can be seen from the example, the order has been mixed after one get(). I'm using python's Queue.PriorityQueue, and ran into the following problem: when inserting several elements to the queue which have the same priority, I would expect the queue to serve them in the order of insertion (FIFO).

Python priority queue by object key