priority queue in python

1class Solution:
2    def mergeKLists(self, lists: List[ListNode]) -> ListNode:
3        
4        setattr(ListNode, "__lt__", lambda self, other: self.val <= other.val)
5            
6        pq = []
7        for l in lists:
8            if l:
9                heapq.heappush(pq,  l)
10        
11        out = ListNode(None)
12        head = out
13        while pq:
14            l = heapq.heappop(pq)
15            head.next = l
16            head = head.next
17            if l and l.next:
18                heapq.heappush( pq, l.next)
19            
20        return out.next
21

1from queue import PriorityQueue
2
3class PqElement(object):
4    def __init__(self, value: int):
5        self.val = value
6
7    #Custom Compare Function (less than or equsal)
8    def __lt__(self, other):
9        """self < obj."""
10        return self.val > other.val #Compare Function For Max Heap - Max element on top
11
12    #Print each element function
13    def __repr__(self):
14        return f'PQE:{self.val}'
15
16#Usage-
17pq = PriorityQueue()
18pq.put(PqElement(v))       # Add Item      - O(Log(n))
19topValue = pq.get()        # Pop top item  - O(1)
20topValue = pq.queue[0].val # Get top value - O(1)
21pqSize = pq.qsize()        # Provide Queue Size - O(1)
22isEmpty = pq.empty()       # Is PQ is empty

1from queue import PriorityQueue
2
3class PqElement(object):
4    def __init__(self, value: int):
5        self.val = value
6
7    #Custom Compare Function (less than or equsal)
8    def __lt__(self, other):
9        """self < obj."""
10        return self.val > other.val
11
12    #Print each element function
13    def __repr__(self):
14        return f'PQE:{self.val}'
15
16#Usage-
17pq = PriorityQueue()
18pq.put(PqElement(v))       #Add Item      - O(Log(n))
19topValue = pq.get()        #Pop top item  - O(1)
20topValue = pq.queue[0].val #Get top value - O(1)