Python学习-------------------三级菜单简单版

题目：

多级菜单
         1.三级菜单
         2.可依次选择进入的各子菜单
         3.所需新知识点：列表、字典

ReadMe：

这个做循环，比较绕脑子

点开运行即可

Mind Map：

代码：

 #!/usr/bin/env python
 #py3.5
 #2018.02.06
 #-*- Coding:utf-8 -*-
 # Author:Eric.Shen
 #多级菜单
 #1.三级菜单
 #2.可依次选择进入的各子菜单
 #3.所需新知识点：列表、字典

 #自己建立一个三级字典
 menu = {
     "衣服":{
         "男士":["上衣","下衣","鞋包","皮带"],"女士":["上衣","裤子","裙子","鞋包"],"儿童":["上衣","下衣","鞋包"]},
     "汽车":{
         "精品车":["宝马","奔驰","路虎"],"二手车":["大众","本田","荣威"]},
     "食物":{"肉":["肥肉","瘦肉","肥瘦"]}
 }

 #将三级菜单的key赋值product_list
 product_list = list(menu.keys())#获得一级菜单
 while True:
     print("菜单".center(50,"*"))
     for line in product_list:
         print(product_list.index(line),line)
     print("------------------")
     choice = input("请输入编号或者输入q退出b返回：")
     if choice.isdigit():
         choice = int(choice)
         if choice >= 0 and choice < len(product_list):
             choice_name = product_list[choice]#获得第一级Id
             product = list(menu[choice_name].keys())#获得选择商品的下一级菜单
             while True:
                 print("商品".center(50,"*"))
                 for line2 in product:#打印二级菜单
                     print(product.index(line2),line2)
                 print("----------------")
                 choice_product = input("请输入编号或者输入q退出b返回：")
                 if choice_product.isdigit():
                     choice_product = int(choice_product)
                     if choice_product >= 0 and choice_product < len(product_list):
                         choice_name2 = product[choice_product]#获得第二级的Id
                         choice_name2_list = menu[choice_name][choice_name2]#获得第二级菜单
                         while True:
                             print("衣物".center(50,"*"))
                             for line3 in  choice_name2_list:
                                 print(choice_name2_list.index(line3),line3)
                             back_or_quit = input("返回输入b，退出输入q")
                             if back_or_quit == "b":
                                 break
                             elif back_or_quit == "q":
                                 exit()
                             else:
                                 print("输入错误！")
                     else:
                         print("输入%d不存在"%(choice_product))
                 elif choice_product == "q":
                     exit()
                 elif choice_product == "b":
                     break
                 else:
                     print("输入非法！")
         else:
             print("输入%d不存在"%(choice))
     elif choice == "q":
         exit()
     elif choice == "b":
         break
     else:
         print("输入非法！")

欢迎指错