python中函数与递归的练习

1. 求一个十进制的数值的二进制的0、1的个数

2. 实现一个用户管理系统（要求使用容器保存数据） [{name: xxx, pass: xxx, ……},{},{}]

   users = []
   
   
   # 用户类，包含基本信息
   class User:
       def __init__(self, name, password, email=None):
           self.name = name
           self.password = password
   
       def __str__(self):
           return f"User(Name: {self.name}, Password: {self.password})"
   
   
   # 用户管理系统
   class UserManager:
       def __init__(self):
           self.users = users
   
       def add_user(self, user):
           self.users.append(user.__dict__)
           print(f"User {user.name} added successfully.")
   
       def get_user(self, name):
           for user_info in self.users:
               if user_info['name'] == name:
                   return user_info
           return None
   
       def list_users(self):
           for user_info in self.users:
               print(user_info)
   
   
   user_manager = UserManager()
   
   # 添加用户
   user1 = User('张三&#