Question

I’m using python to manage a queue of strings to process. It has a couple of requirments:

• Each string is matched to a priority and is processed based solely on that value.
• Strings can be added to this queue dynamically but no duplicate Strings are allowed in the queue. If a duplicate is submitted then it must be identified and ignored.

So is there any python datatype that will allow something like this? Or do I have to write my own?

If there isn’t a native one then, I’m thinking of maintaining two structures.

1. A heapq which will maintain the strings and their priority
2. A list which maintains a hash of the strings to check whether the string is already stored

As long as these do not fall out of sync it should solve the problem.

Answer 1

That sounds like a reasonable approach. I would use a set instead of a list since it has more efficient membership checking and you don’t need to maintain order (since you do it in the heapq)