验证码

import random
def func(a=6, alpha=True):
    s = ""
    for i in range(a):
        num = str(random.randint(0, 9))
        if alpha:
            alpha_upper = chr(random.randint(65, 90))
            alpha_lower = chr(random.randint(97, 122))
            num = random.choice([num, alpha_upper, alpha_lower])
        s = s + num
    return s
print(func())