题解 | #禁止重复注册#

current_users=['Niuniu','Niumei','GURR','LOLO']
new_users=['GurR','Niu Ke Le','LoLo','Tuo Rui Chi']
current_users=list(map(lambda x:x.lower(),current_users))

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