注册（registered.py）

#! /uer/bin/python3.5
# -*- coding: utf-8 -*-


import hashlib,json,re



def get_md5(user,password):
    md5 = hashlib.md5()
    md5.update((user+password+"The*Sale").encode('utf-8'))
    return md5.hexdigest()


mail_gesi = ["qq.com","gmail.com","163.com"]


def register():
    with open("date.txt",'r') as f:
        user_date = json.load(f)
    with open("find_password_date.txt",'r') as a:
        find_password = json.load(a)
        while True:
            mail_list = [x for x in find_password.values()]    # 获取之前用户输入过的所有邮箱
            user = str(input("New User: "))
            password = str(input("Password: "))
            password_chack = [i for i in password if i.isalpha()]    # 判断 password 中是否有英文字母
            mail = str(input("Mail: "))
            save_md5 = get_md5(user,password)    # 将用户输入的密码加密
            mail_split = mail.split("@")
            re_mail = re.findall(r"[^a-z0-9]",mail_split[0])
            if user in user_date:
                print("'%s' 已存在，请重新输入！" % user)
                continue
            elif len(password) < 6 or password_chack == []:    # 判断密码是否大于6个和是否带有英文字母
                print("密码太弱，请输入6位以上的并且至少有一个英文字母")
            elif mail in mail_list:     # 判断有没有被其他用户输入过
                print("此邮箱已注册！")
            elif re_mail != [] or mail_split[-1] not in mail_gesi:   # 判断邮箱格式
                print("请输入正确的邮箱") 
            else:
                user_date[user]=save_md5
                find_password[user]=mail
                print("'%s' 创建成功！" % user)
                with open("date.txt",'w') as s:
                    json.dump(user_date,s)
                with open("find_password_date.txt",'w') as x:
                    json.dump(find_password,x)
                break


                with open("find_password_date.txt",'w') as x:
                    json.dump(find_password,x)
                break

找回密码（Find_password.py）

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

import json
from registered import *

def Find_password():
    with open("find_password_date.txt",'r') as f:
        mail_date = json.load(f)
    with open("date.txt",'r') as d:
        user_date = json.load(d)
        while True:
            user = str(input("User: "))
            mail = str(input("Mail: "))
            if user in mail_date and mail == mail_date[user]:
                while True:
                    new_password = str(input("New Password: "))
                    enter_password = str(input("Enter Password: "))
                    if new_password == enter_password:
                        get_new_md5 = get_md5(user,new_password)
                        user_date[user]=get_new_md5
                        print("密码修改成功！")
                        with open("date.txt",'w') as x:
                            json.dump(user_date,x)
                            break
                    else:
                        print("两次输入的密码不相同，请重新输入！")
                break
            else:
                print("用户名或错误!")

登录（login.py）

# -*- codint: utf-8 -*-

import json
from registered import *
from Find_password import *




while True:
    print("User Login!")
    with open("date.txt","r") as f:
        user_date = json.load(f)
        user = str(input("User Name: "))
        password = str(input("Password: "))
        save_md5 = get_md5(user,password)
        if user not in user_date:
            print("用户名: '%s' 不存在，请注册！" % user)
            print("输入'q'退出,输入'a'继续注册")
            sele = str(input("q or a: "))
            if sele == "q":
                print("已退出！")
                break
            print("REGISTERED!")
            register()
        else:
            if user in user_date and user_date[user]==save_md5:
                print("Login success!")
                print("Welcome %s" % user)
                break
            else:
                print("密码或帐号错误，是否需要找回密码？(y/n)")
                enter = str(input(">>> "))
                if enter == "Y" or enter == "y":
                    Find_password()
                else:
                    continue

还需要创建两个txt文本储存数据：date.txt find_password_date.txt

date.txt的内容：{"root": "63a9f0ea7bb98050796b649e85481845"}

find_password_date.txt内容：{"root": "1473018671@gmail.com"}

最后运行login.py