三级菜单

#Author:xiesongyou

China= {
     '山东' : {
         '青岛' : ['四方','黄岛','崂山','李沧','城阳'],
         '济南' : ['历城','槐荫','高新','长青','章丘'],
         '烟台' : ['龙口','莱山','牟平','蓬莱','招远']
                },
     '江苏' : {
         '苏州' : ['沧浪','相城','平江','吴中','昆山'],
         '南京' : ['白下','秦淮','浦口','栖霞','江宁'],
         '无锡' : ['崇安','南长','北塘','锡山','江阴']
                },
     '浙江' : {
         '杭州' : ['西湖','江干','下城','上城','滨江'],
         '宁波' : ['海曙','江东','江北','镇海','余姚'],
         '温州' : ['鹿城','龙湾','乐清','瑞安','永嘉']
                },
     '安徽' : {
         '合肥' : ['蜀山','庐阳','包河','经开','新站'],
         '芜湖' : ['镜湖','鸠江','无为','三山','南陵'],
        '蚌埠' : ['蚌山','龙子湖','淮上','怀远','固镇']
                },
     '广东' : {
         '深圳' : ['罗湖','福田','南山','宝安','布吉'],
         '广州' : ['天河','珠海','越秀','白云','黄埔'],
         '东莞' : ['莞城','长安','虎门','万江','大朗']
                }
        }

exit_flag = False
while not exit_flag:
    print("省".center(50,'-'))
    for index,province in enumerate(China):
        print(index+1,":",province)
    choice_province=input("请选择省编号(输入q退出)：")
    province_list = list(China.keys())
    if choice_province.isdigit():
        choice_province = int (choice_province)
        if choice_province > 0 and choice_province <= len(province_list):
            while not exit_flag :
                print("市".center(50, '-'))
                province_name=province_list[choice_province - 1]
                city = list(China[province_name].keys())
                for c in city:
                    print(city.index(c) + 1, c)
                choice_city = input("请选择市(b返回上级菜单，或输入q退出)：")
                if choice_city.isdigit():
                    choice_city = int(choice_city)
                    if choice_city > 0 and choice_city <= len(city):
                        while not exit_flag:
                            print("县".center(50, '-'))
                            city_name = city[choice_city - 1]
                            country_name = list(China[province_name][city_name])
                            for ctry in country_name:
                                print(country_name.index(ctry) + 1, ctry)
                            country_choice = input("请选择县(b返回上级菜单，或输入q退出)：")
                            if country_choice.isdigit():
                                country_choice = int(country_choice)
                                if country_choice > 0 and country_choice <= len(country_name):
                                    print("你的选择是：",province_name,city_name,country_name[country_choice-1])
                                    exit_flag = True
                                else:
                                    print("输入错误序号！")
                            elif country_choice == "q":
                                exit_flag = True
                            elif country_choice == "b":
                                break
                    else:
                        print("输入序号错误！")
                elif choice_city == 'q':
                    exit_flag = True
                elif choice_city == 'b':
                    break
        else:
            print("输入序号错误！")
    elif choice_province == 'q':
        exit_flag = True