题解 | #禁止重复注册#

import sys


current_users=['Niuniu','Niumei','GURR','LOLO']
current_users_lower=[current_users[0].lower(),current_users[1].lower(),current_users[2].lower(),current_users[3].lower()]
new_users=['GurR','Niu Ke Le','LoLo','Tuo Rui Chi']
for name in new_users:
        if name.lower() in current_users_lower:
            print("The user name {} has already been registered! Please change it and try again!".format(name))
        else:
            print("Congratulations, the user name {} is available!".format(name))