【Rollo的Python之路】Python:三级菜单练习

menu = {
    "深圳":{
        "罗湖":{
            "罗湖火车站": {},
            "东门": {},
            "国贸": {},
            "布心": {},
        },
        "福田":{
            "香蜜湖": {},
            "华强北": {},
            "华强南": {},
            "市民中心": {},
        },
        "南山": {
            "南山中心城": {},
            "南头关": {},
            "华侨城": {},
        },
        "宝安": {
            "宝安中心": {},
            "西乡": {},
            "松岗": {},
        },
        "龙岗": {
            "龙岗中心城": {},
            "布吉": {},
            "坂田": {},
        },
    },
    "湖南":{
        "长沙": {
            "大学城区":{},
        },
        "衡阳":{
            "衡阳":{
                "火车站":{},
            },
        },
        "郴州":{
            "北湖区": {},
            "苏仙区": {},
            "东湖区": {},
        },

    },
    "北京":{},
}

back_flag = False
exit_flag = False
while not back_flag and not exit_flag:
    for key in menu:
        print(key)
    choice = input("please choose the address:").strip()
    if choice in menu:
        while not back_flag and not exit_flag:
            for key2 in menu[choice]:
                print(key2)
            choice2 = input("please choose the address").strip()
            if choice2 == "b":
                back_flag = True
            if choice2 == "q":
                exit_flag = True
            if choice2 in menu[choice]:
                while not back_flag and not exit_flag:
                    for key3 in menu[choice][choice2]:
                        print(key3)
                    choice3 = input("please choose the address").strip()
                    if choice3 == "b":
                        back_flag = True
                    if choice3 == "q":
                        exit_flag = True
                    if choice3 in menu[choice][choice2]:
                        while not back_flag and not exit_flag:
                            for key4 in menu[choice][choice2][choice3]:
                                print(key4)
                            choice4 = input("please choose the address").strip()
                            print("last layer")
                            if choice4 == "b":
                                back_flag = True
                            if choice4 == "q":
                                exit_flag = True
                                break
                        else:
                            back_flag = False
                else:
                    back_flag = False
        else:
            back_flag = False