写代码：用户交互显示类似省市县三级联动的选择

仍然需要修改：
 1 # encoding: utf-8
 2 # 用户交互显示类似省市县N级联动的选择
 3 # * 允许用户增加内容
 4 # * 允许用户查看某一个级别内容
 5 
 6 dic = {
 7     "江西": {
 8         "萍乡": ["安源", "彭高", "上栗"],
 9         "新余": ["良山", "新钢", "兴安岭"],
10     },
11     "北京": {
12         "大兴区": ["礼贤镇", "魏善庄镇", "北臧村镇"],
13         "昌平区": ["沙河", "化庄", "白浮泉"],
14     },
15     "福建": {
16         "莆田": ["荔城", "西天尾", "九化山"],
17         "厦门": ["湖里", "思明", "海仓"],
18     }
19 }
20 print("目前可查询的省份：江西、北京、福建")
21 province = input("请输入省份或者输入N新建： ")
22 
23 if province == "N":
24     new_province = input("请输入省份：")
25     new_city = input("请输入城市：")
26     new_town = input("请输入城镇信息：")
27     dic[new_province] = {new_city: [new_town]}
28 
29 while province not in dic:
30     print("输入错误省份，请从新输入")
31     province = input("请输入省份或者输入N新建： ")
32 
33 while province in dic:
34     new_menu = dic[province]
35     for k in new_menu:
36         print(k, end="
")
37     choice_city = input("请输入城市：")
38     if choice_city not in new_menu:
39         print("错误城市输入，请从新输入： ")
40         continue
41     else:
42         new_menu2 = new_menu.get(choice_city)
43         for i in new_menu2:
44             print(i, end="
")
45         choice_town = input("请输入城镇信息：")
46         if choice_town in new_menu2:
47             print(
48                 "信息输入正确，省份：{}，城市：{}，城镇：{}".format(
49                     province,
50                     choice_city,
51                     choice_town))
52             break