Python字典嵌套

 import  copy

 menu = {

     "计算机科学与技术":{

         "程序编程":{

            "传统语言":{

                "C++":"LLWH",

                "C#":"从入门到入土",

                "C#":"haha C#",

            },

             "网站编程":

                 {

                     "PHP":"论坛",

                     "Java":"电商网站",

                     "Python":"全栈开发",

                 },

             "服务器编程":

                 {

                     "视频服务器":"C++",

                     "游戏服务器":"python",

                     "棋牌服务器":"go 语言"

                 },

         },

         "网页设计":{

             "前端":

                 {

                     "优化":"CSS",

                     "格局":"HTML",

                     "数据交换":"JavaScript",

                 },

             "后端":

                 {

                     "服务器":"Linux",

                 }

         }

     }

 }

 menu_copy = copy.deepcopy(menu)

 #print(menu_copy.pop("计算机科学与技术")) # 字典嵌套只能删除第一层

 #print("***"*30)

 for x in menu_copy:

     for x01 in  menu_copy[x]:

         print("-->根节点是{0}\n".format(x01))

         if x01 is not None:

             for x02 in  menu_copy[x][x01]:

                 print("-------->子节点是{0}\n".format(x02))

                 if x02 is not None:

                     for x03 in menu_copy[x][x01][x02]:

                         print("------------>key    {0}, value  {1}\n ".format(x03,menu_copy[x][x01][x02][x03]))

 #print(menu_copy.keys())# 返回 第一个嵌套的子节点