小题目大智慧（二）

产生的账号是以@163.com结尾，长度由用户输入，产生多少条也由用户输入，用户名不能重复，用户名必须由大写字母、小写字母、数字组成，结果如下图：

import string, random
mail_list = []
def Mail():
    count = int(input('请输入生成邮箱的个数:'))
    for i in range(count):
        src1 = random.sample(string.ascii_lowercase, 3)
        src2 = random.sample(string.ascii_uppercase, 3)
        src3 = random.sample(string.digits, 2)
        mail = ''.join(src1)+''.join(src2)+''.join(src3)+'@163.com'
        if mail not in mail_list:
            mail_list.append(mail)
    return mail_list

mails = Mail()
for mail in mails:
    fw = open('mail.txt', 'a')
    fw.write(mail+'
')