Random Tree Generator

RandomTreeGenerator.py

from random import *

def randTree(N):
    edges = []
    comps = [[i] for i in range(N)]
    for _ in range(N - 1):
        i = randint(0, len(comps) - 1)
        j = randint(0, len(comps) - 2)
        if j == i:
            j += 1
        if len(comps[i]) < len(comps[j]):
            i, j = j, i
        comps[i], comps[-2] = comps[-2], comps[i]
        comps[j], comps[-1] = comps[-1], comps[j]
        u = choice(comps[-2])
        v = choice(comps[-1])
        edges.append((min(u, v), max(u, v)))
        while len(comps[-1]) > 0:
            comps[-2].append(comps[-1].pop())
        comps.pop()
    return edges

for u, v in randTree(10):
    print(u, v)