三级菜单的实现（python程序）

_author_ = "zhanzhengrecheng"

data={
    "陕西":{
        "宝鸡":{"扶风县":["段家镇","城关镇"],},
        "渭南":{},
        "延安":{},
        "西安":{},
        },
    "河北":{
        "保定":{"唐县":["杨庄","黄庄"]},
        "石家庄":{},
        "唐山":{},
        "衡水":{},
        },
    }

exit_flag = False

while not exit_flag:
    for i1 in data:
        print(i1)
    choice1 = input("选择进入1111>>:")
    if choice1 in data:
        while not exit_flag:
            for i2 in data[choice1]:
                print("\t",i2)
            choice2 = input("选择进入2222>>:")
            if choice2 in data[choice1]:
                while not exit_flag:
                    for i3 in data[choice1][choice2]:
                        print("\t\t",i3)
                    choice3 = input("选择进入3333>>:")
                    if choice3 in data[choice1][choice2]:
                        for i4 in data[choice1][choice2][choice3]:
                            print("\t\t\t",i4)
                        choice4 = input("最后一层，按b返回")
                        if choice4 == "b":
                             pass
                        elif choice4 =="q":
                            exit_flag = True
                    if choice3 == "b":
                        break
                    elif choice3 == "q":
                        exit_flag = True
            if choice2 == "b":
                break
            elif choice2 == "q":
                exit_flag = True