python中怎么对一个数进行因式分解？

import time

# 对一个数进行因式分解

def factorization(num):

  factor = []

  while num > 1:

    for i in range(num - 1):

      k = i + 2

      if num % k == 0:

        factor.append(k)

        num = int(num / k)

        break

  return factor

st = time.perf_counter()

print(factorization(707829217))

et = time.perf_counter()

print("用时:", et - st)