current_users = ['Niuniu','Niumei','GURR','LOLO'] new_users = ['GurR','Niu Ke Le','LoLo','Tuo Rui Chi'] for user in new_users: if user.lower() in map(lambda x:x.lower(), current_users): print("The user name {} has already been registered! Please change it and try again!".format(user)) else: print("C...