多级菜单初写(dict使用)

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# name:zzyu
map = {
    "中国":{
        "北京":{
            "昌平区":{
                "沙河镇":["西沙屯","路庄","王庄"],
                "阳坊镇":["东贯市","西贯市","阳坊"],
            },
            "密云区":{
                "高岭镇":["四合村","燕落村","高岭村"],
                "密云镇":["阳光小区","月光小区","星光小区"]
            },
            "朝阳区":{
                "北苑":["北苑小区","茉莉园小区","丽春园小区"],
                "霍营":["霍营地铁","望京地铁","北苑地铁"]
            }
        },
        "河北":{
            "河北省":{
                "石家庄":["石家庄小区","二小区","三小区"],
                "保定":["保一区","保二区","保三区"]
            },
            "唐山":{
                "开平区":["大麻各庄村","茅草营村","粟园镇"],
                "古冶区":["刘各庄村","小寨村","养马庄村"]
            },
            "廊坊":{
                "安次区":["小屯村","青坨村","东北尹"],
                "武清区":["新刘庄","前台","北寺"]
            }
        },
        "天津":{
            "北辰区":{
                "一镇":["心罗园","紫罗园","心泽园"],
                "二镇":["荣业园","荣熙园","荣翔园"]
            },
            "红桥区":{
                "三镇":["水竹园","水木天成","华水大厦"],
                "四镇":["运通园","顺通园","天阔园"]
            },
            "西青区":{
                "五镇":["西清医院","西青政府","西青银行"],
                "六镇":["双河新村","河畔人家","文化中心"]
            }
        }
    }
}
print("\033[31;1m选择期间按<q>退出，按<b>返回上一层\033[0m")
exit_flag = False
while not exit_flag:
    for i in map:
        print(i)
    user_choice = input("请选择您的国家：")
    if user_choice in map:
        while not exit_flag:
            for j in map[user_choice]:
                print(j)
            user_choice_1 = input("请选择您的城市：")
            if user_choice_1 in map[user_choice]:
                while not exit_flag:
                    for p in map[user_choice][user_choice_1]:
                        print(p)
                    user_choice_2 = input("请选择您所在的区县：")
                    if user_choice_2 in map[user_choice][user_choice_1]:
                        while not exit_flag:
                            for k in map[user_choice][user_choice_1][user_choice_2]:
                                print(k)
                            user_choice_3 = input("请选择您所在的乡镇：")
                            if user_choice_3 in map[user_choice][user_choice_1][user_choice_2]:
                                for f in map[user_choice][user_choice_1][user_choice_2][user_choice_3]:
                                    print(f)
                                user_choice_4 = input("\033[31;1m已到最后一层，请选择<b>或<q>:\033[0m")
                                if user_choice_4 == "q":
                                    exit_flag = True
                                elif user_choice_4 == "b":
                                    pass
                            elif user_choice_3 == "q":
                                exit_flag = True
                            elif user_choice_3 == "b":
                                break
                            else:
                                print("输入有误请重新输入.....")
                    elif user_choice_2 == "q":
                        exit_flag = True
                    elif user_choice_2 == "b":
                        break
                    else:
                        print("输入有误请重新输入.....")
            elif user_choice_1 == "q":
                exit_flag = True
            elif user_choice_1 == "b":
                break
            else:
                print("输入有误请重新输入.....")
    elif user_choice == "b":
        print("已返回，请重新输入。")
    elif user_choice == "q":
        print("再见")
        break
    else:
        print("您输入的国家不存在，请重新输入.....")