def register_user(): x=input("register user:") return x user1=register_user() user2=register_user() chat={ user1:[], user2:[] } def sending_mess(): print(f'{user1}:Type "s" to send a message(if no write "d"):') x=input() if x =="s": print(f"message from {user1} to {user2}:") message=input() print(f'{user2}:You received a message') chat[user1] += ["s"] chat[user2] += ["r"] return message elif x=="d": print(f'{user2}:Type "s" to send a message(if no write "d"):') y=input() if y =="s": print(f"message from {user2} to {user1}:") message=input() print(f'{user1}:You received a message') chat[user2] += ["s"] chat[user1] += ["r"] return message elif y=="d": print("") else: print("please try again") return message message=sending_mess() chat[user1] += [message] chat[user2] += [message] print(chat)