Finding value in a priority queue in python

Question

Is there a good way to delete values from the class queue.PriorityQueue() without ruining the priority queue? I guess theoretically I could make a loop that will get all the values until I reach the one I need, and insert all of the other ones back one without including the deleted node. This seems like overkill though. Is there a better way?

Edit: I'm trying to make a priority queue of nodes with the key being the cost to get to said node. If I find a cheaper way of getting to the node I would like to replace it on the priority queue with the cheaper cost.

Maybe, but if you want to peek at other values, then PriorityQueue isn't the data-structure you want. Tell us more about the use-case: do you want to find the top-n, nth-largest or what? In any case sounds like you really need some other data-structure. — smci
– smci, Commented May 19, 2014 at 4:26
This definitely indicates a problem with the choice of data structure or algorithm. — perreal
– perreal, Commented May 19, 2014 at 4:27

shx2 · Accepted Answer · 2014-05-19 05:05:22Z

2

The queue module and its classes are tools primarily meant to be used for synchronization (multi-threading/multi-processing), rather than being pure data structure.

Perhaps you'll find any of that answers to this question suits your needs, or just use heapq directly.

answered May 19, 2014 at 5:05

shx2

64.8k17 gold badges139 silver badges166 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Vinayak Garg · Accepted Answer · 2014-05-19 04:52:37Z

1

No, there isn't a good way to delete any arbitrary value in priority queue. You can only extract top (min/max) element from priority queue.

A set data structure (balanced binary search tree) would be better, because you can find and delete node in O(log n).

answered May 19, 2014 at 4:52

Vinayak Garg

6,63410 gold badges56 silver badges82 bronze badges

Collectives™ on Stack Overflow

Finding value in a priority queue in python

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related