current_users = ['Niuniu', 'Niumei', 'GURR', 'LOLO'] new_users = ['GurR', 'Niu Ke Le', 'LoLo', 'Tuo Rui Chi'] for i in new_users: if i.upper() in current_users: print(f'The user name {i} has already been registered! Please change it and try again!') else: print(f'Congratulations, the user name {i} i...