如何设计一个支持在线答题中的学校或机构多用户的系统

class User:
    def __init__(self, username, password, role, school):
        self.username = username
        self.password = password
        self.role = role
        self.school = school

class UserManager:
    def __init__(self):
        self.users = []

    def register(self, username, password, role, school):
        user = User(username, password, role, school)
        self.users.append(user)

    def login(self, username, password):
        for user in self.users:
            if user.username == username and user.password == password:
                return user
        return None

# 示例代码使用了面向对象的方法，创建了一个User类和UserManager类。
# User类包含了用户名、密码、角色和所属学校等属性；
# UserManager类包含了用户注册和登录的方法。

user_manager = UserManager()
user_manager.register("admin", "admin123", "admin", "学校A")
user_manager.register("teacher1", "teacher123", "teacher", "学校A")
user_manager.register("student1", "student123", "student", "学校A")

user = user_manager.login("admin", "admin123")
if user is not None:
    print("用户登录成功！")
    print("用户角色：", user.role)
    print("所属学校：", user.school)
else:
    print("用户登录失败！")