python字典中通过值找键（包含：嵌套字典查找，一键对多值的情况）

直接上代码。

province = {"山东":{"济南":["槐荫区","历下区"],"青岛":["黄岛区","城阳区"],"济宁":"兖州区"},"辽宁":"沈阳","吉林":"长春"}
print(type(province))
char = input("你想查询"
      "\n1、市："
      "\/2、县/区：")
if char == '1':
    city = input("请出入要查询的城市名：")
    for key, val in province.items():

        if city in province[key]:
            print("该城市属于：",key)
        else:
            print("数据中暂无该城市。")
            break

elif char == '2':
    county = input("请出入要查询的县区：")

    for key, val in province.items():

        #print(province[key])
        if isinstance(province[key],dict): #找出值为字典的 键值对
            #print(province[key])
            for key2 , val2 in province[key].items():#遍历值为字典的部分
               # print(province[key].values())
                if county in province[key][key2]:
                    print("该区属于：",key,"省",key2,"市")
        else:
            print("数据中暂无该区县。")
            break
else:
    print("输入错误")