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