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 names in new_users:
    n = 0
    if names.upper() in current_users:
        print(f"The user name {names} has already been registered! Please change it and try again!")
        n  = 1
    if n == 0:
        print(f"Congratulations, the user name {names} is available!")