如何随机生成大写字母和数字组成的字符串

#!/usr/bin/env python

# -*- coding:utf-8 -*-

import random

def getRandomSet(bits):

    num_set = [chr(i) for i in range(48,58)]

    char_set = [chr(i) for i in range(65,90)]

    total_set = num_set + char_set

    value_set = "".join(random.sample(total_set, bits))

    return value_set

if __name__ == '__main__' :

    strings = getRandomSet(26)

    print(strings)