python生成指定长度的随机数密码

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#导入random和string模块
import random, string
def GenPassword(length):
    #随机出数字的个数
    numOfNum = random.randint(1,length-1)
    numOfLetter = length - numOfNum
    #选中numOfNum个数字
    slcNum = [random.choice(string.digits) for i in range(numOfNum)]
    #选中numOfLetter个字母
    slcLetter = [random.choice(string.ascii_letters) for i in range(numOfLetter)]
    #打乱这个组合
    slcChar = slcNum + slcLetter
    random.shuffle(slcChar)
    #生成密码
    genPwd = ''.join([i for i in slcChar])
    return genPwd
if __name__ == '__main__':
    print GenPassword(6)