Simple python union find

uf.py

class UF:
    def __init__(self, n):
        self.par = list(range(n))
        self.rank = [0] * n

    def find(self, x):
        if x != self.par[x]:
            self.par[x] = self.find(self.par[x])
        return self.par[x]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if self.rank[x] > self.rank[y]:
            self.par[y] = x
        else:
            self.par[x] = y
            if self.rank[x] == self.rank[y]:
                self.rank[y] += 1