day17作业-1

import json
def login(name,password):
    with open('./namelist.txt','r',encoding='utf-8') as f:
        for item in json.load(f):
            if item.get('name') == name and item.get('password') == password:
                return True
        else:
            print('用户名不存在或用户名密码错误')
            return False

def signup(name):
    with open('./namelist.txt', 'r', encoding='utf-8') as f:
        flag = 1
        while flag:
            for item in json.load(f):
                if item.get('name') == name:
                    name = input('用户名已存在请重新输入：')
                    break
            else:
                flag = 0
        return True


with open('./namelist.txt','r+',encoding='utf-8') as f:
    if f.read() == '':
        f.write('[{}]')


while True:
    print("""
欢迎来到学生管理系统
1.登录
2.注册
3.退出
""")
    choice = input('请选择：')
    if choice == '1':
        name = input('请输入用户名：')
        password = input('请输入密码：')
        if login(name,password) == True:
            print("""
 欢迎%s
 1.添加学生
 2.查看学生
 3.删除学生
 4.返回           
            """ % name)
            choice1= input('请输入：')
            continue
    elif choice == '2':
        while True:
            name = input('请输入用户名：')
            signup(name)
            password = input('请输入密码：')
            with open('./namelist.txt','r',encoding='utf-8') as f:
                former_members = json.load(f)
                new_member = {'name':name,'password':password}
                former_members.append(new_member)
            with open('./namelist.txt', 'w', encoding='utf-8') as f:
                json.dump(former_members,f)
            print("""
 注册成功
 1.继续注册
 2.返回           
            """)
            choice2 = input('请输入：')
            if choice2 == '1':

                continue
            else:
                break
    else:
        break