#!/usr/local/bin/python3# -*- coding:utf-8 -*-province={    '江苏省':{        '南京市':['秦淮区','玄武区','栖霞区'],        '苏州市':['姑苏区','虎丘区','吴中区'],        '无锡市':['滨湖区','惠山区','锡山区']    },    '浙江省':{        '杭州市':['西湖区','拱墅区','萧山区'],        '温州市':['鹿城区','瓯海区','龙湾区'],        '宁波市':['镇海区','海曙区','江北区']    }}while True:    print("hello,which province do you want to choose?")    for i in province:        print(i)    province_choose=input("-->")    while True:        if province_choose in province.keys():            print("which city do you want to choose?")            for j in province[province_choose]:                print(j)            city_choose=input("-->")            while True:                if city_choose in province[province_choose].keys():                    print("here are the areas:")                    for k in province[province_choose][city_choose]:                        print(k)                    area_choose=input("-->")                    while True:                        if area_choose in province[province_choose][city_choose]:                            print("there is nothing to show...")                            break                        elif area_choose=='q':                            exit()                        elif area_choose=='r':                            break                        else:                            print("your choice was unexist!")                            break                elif city_choose=='r':                    break                elif city_choose=='q':                    exit()                else:                    print("your choice was unexist!")                    break                if area_choose=='r':                    break        elif province_choose=='q' or province_choose=='r':            exit()        else:            print("your choice was unexist!")            break        if city_choose=='r':            break