How to make heapq evaluate the heap off of a specific attribute?

Question

I wish to hold a heap of objects, not just numbers. They will have an integer attribute in them that the heap can sort by. The easiest way to use heaps in python is heapq,

Answer 1

I had the same question but none of the above answers hit the spot although some were close but not elaborated enough. Anyway, I did some research and tried this piece of code and hopefully this should be sufficient for someone next who is looking to get an answer:

The problem with using a tuple is it only uses the first item which is not very flexible. I wanted something similar to std::priority_queue in c++ like this: std::priority_queue, vector>, comparator> pq; where I could design my own comparator which is more common in real world applications.

Hopefully the below snippet helps: https://repl.it/@gururajks/EvenAccurateCylinders

import heapq
class PQNode:

    def __init__(self, key, value):
        self.key = key
        self.value = value

    # compares the second value
    def __lt__(self, other):
        return self.value < other.value

    def __str__(self):
        return str("{} : {}".format(self.key, self.value))

input = [PQNode(1, 4), PQNode(7, 4), PQNode(6, 9), PQNode(2, 5)]
hinput = []
for item in input:
    heapq.heappush(hinput, item)

while (hinput):
    print (heapq.heappop(hinput))