题解 | 禁止重复注册

import sys

current_users = ['Niuniu', 'Niumei', 'GURR', 'LOLO']
new_users = ['GurR', 'Niu Ke Le', 'LoLo', 'Tuo Rui Chi']
processed_current_users = [u.lower() for u in current_users]
processed_new_users = [u.lower() for u in new_users]

for user in new_users:
    if(user.lower() in processed_current_users):
        print(f'The user name {user} has already been registered! Please change it and try again!')
    else:
        print(f'Congratulations, the user name {user} is available!')