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:
    count = 0
    for j in current_users:
        if i.lower() == j.lower():
            count += 1
        else:
            count += 0 
    if count >= 1:
        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!')