Quick Disjoint Set in python (Union Find with path compression)

UnionFind.py

class Node:
    def __init__(self, value):
        self.value = value
        self.rank = 1
        self.parent = self 

class DisjointSet:
    def __init__(self):
        self.mapping = {}
    
    def find(self, u):
        if u not in self.mapping: 
            self.mapping[u] = Node(u)

        node = self.mapping[u]
        if node.parent is not node: 
            node.parent = self.find(node.parent.value) #path compression
        return node.parent
        
    def union(self, u, v):
        p1, p2 = self.find(u), self.find(v)
        if p1 is p2: return False
        
        if p1.rank < p2.rank:
            p1.parent = p2
        elif p2.rank < p1.rank:
            p2.parent = p1
        else:
            p2.parent = p1
            p1.rank += 1
        return True
    
    
    
# example usage to find cycle in undirected graph 
# https://leetcode.com/problems/redundant-connection/

  def findCycle(self, edges: List[List[int]]) -> List[int]:
        dset = DisjointSet()
        
        for u, v in edges:
            if not dset.union(u, v):
                return [u, v]