题解 | #禁止重复注册#

current_users = ["Niuniu", "Niumei", "GURR", "LOLO"]

new_users = ["GurR", "Niu Ke Le", "LoLo", "Tuo Rui Chi"]

for i in new_users:

    if i.lower() in [x.lower() for x in current_users]:

        print(

           f'The user name {i} has already been registered! Please change it and try again!'

        )

    else:

        print(f'Congratulations, the user name {i} is available!')