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 [j.lower() for j 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))
使用了列表推导式