输出质数因子

1、python2

from __future__ import print_function
num = int(raw_input())
i = 2
while num != 1:
    while num % i == 0:
        print(i, end=' ')
        num /= i
    i += 1

2、python3

import sys
num = int(sys.stdin.readline())
i = 2
while num != 1:
    while num % i == 0:
        print(i, end=' ')
        num /= i
    i += 1