''' 多级菜单 需求: 1.现有省/市/县3级结构,要求程序启动后,允许用户可依次选择进入各子菜单 2.可在任意一级菜单返回上一级 3.可以在任意一级菜单退出程序 所需新知识点: 列表/字典 ''' menu = { "山东": { "济南": { "平阴": {}, "商河": {}, "莱芜": {} }, "济宁": { "金乡": {}, "微山": {}, "嘉祥": {} }, "曲阜": { "南辛": {}, "陵城": {}, "防山": {} } }, "北京": { "海淀": { "万寿路": {}, "永定路": {}, "中关村": {} }, "昌平": { "回龙观": {}, "南口": {}, "沙河": {} }, "朝阳": { "呼家楼": {}, "三里屯": {}, "双井": {} } }, "上海": { "黄浦": { "南京东路": {}, "外滩": {}, "瑞金二路": {} }, "徐汇": { "湖南路": {}, "天平路": {}, "枫林路": {} }, "长宁": { "华阳路": {}, "新华路": {}, "江苏路": {} } }, } current_menu = menu layers = [] while True: for i in current_menu: print(i) choice = input(">: ").strip() if choice in current_menu: layers.append(current_menu) current_menu = current_menu[choice] elif choice.upper() == "B": if len(layers) == 0: print("已经到顶了") continue current_menu = layers.pop() ----------------------------------------------微调1------------------------------------ current_menu = menu choices = [] while True: for i in current_menu: print(i) choice = input(">: ").strip() if choice in current_menu: choices.append(choice) current_menu = current_menu[choice] elif choice.upper() == "B": current_menu = menu if len(choices) == 0: print("已经到顶了") continue choices.pop() for i in choices: current_menu = current_menu[i] ''' 比上面的代码多了最后两行,请大佬留言,哪个方式更好一些. ''' ------------------------------------------微调2--------------------------------------- current_menu = menu choices = [] while True: for i in current_menu: print(i) print("q退出 b返回上一级") if len(choices) >= 1: choice = input("%s>: " % '>'.join(choices)).strip() else: choice = input(">: ").strip() if choice in current_menu: choices.append(choice) current_menu = current_menu[choice] elif choice.upper() == "B": current_menu = menu if len(choices) == 0: print("已经到顶了") continue choices.pop() for j in choices: current_menu = current_menu[j] elif choice.upper() == "B": break