题解 | #禁止重复注册#

# 创建当前用户列表
current_users = ['Niuniu', 'Niumei', 'GURR', 'LOLO']

# 创建新用户列表
new_users = ['GurR', 'Niu Ke Le', 'LoLo', 'Tuo Rui Chi']

# 遍历新用户列表
for new_user in new_users:
    # 如果新用户名在当前用户列表中，则输出提示信息
    if new_user.upper() in current_users:
        print(f"The user name {new_user} has already been registered! Please change it and try again!")
    # 否则输出成功信息
    else:
        print(f"Congratulations, the user name {new_user} is available!")