python 循环嵌套

需求如下：

　　1.

 #定义商品列表类
 # def shangpin_list():
 #     for i in com_list:
 #         print(com_list.index(i),end="   ")
 #         for j in i:
 #             print(j,end="   ")
 #         print()
 #     else:
 #         return True

 #程序入口

 salary = int(input("请输入您的工资："))
 com_list = [['iphone6s',5000],['mac book',9000],['coffee',32],['python book',80]]
 shopping_cart_list = [] #购物车
 cum_money = [] #账单
 car_list = []
 com_count = 0
 while True:
     if salary >= 0:
         for i in com_list:  #展示商品
             print(com_list.index(i),end="   ")
             for j in i:
                 print(j,end="   ")
             print()
         gm = input('''想买点啥？
 输入商品编号即可购买，输入quit退出商城。
 请输入》》》''') #开始购物
         if gm != 'quit':
             try:
                 gm = int(gm)
                 salary = salary - int(com_list[gm][1])
                 if salary >= 0:
                     com = com_list[gm][0]   #购买的商品
                     com_money = com_list[gm][1]
                     shopping_cart_list.append([com,com_money])      #购买的商品
                     com_count = com_count+com_money
                     print('购买',com,'您需要支付',com_money,'元--->扣除后余额为：%d'%salary)
                 else:
                     print("余额不足，骚年快去挣钱吧！")
             except ValueError or IndexError as err:
                 print("输入有误呕！")
         else:
             print( '本次您购买了以下商品,共计花费：%d元'%com_count)
             for ij in shopping_cart_list:
                 print( '%s  %s元'%((ij[0]),ij[1]))
             else:
                 exit("您还有余额%d欢迎下次光临"%salary)
     continue

购物车

 #!/user/bin/env python3
 # -*- coding=utf-8 -*-
 #__author__:gq
 #date:2016/8/24 0024

 dic = {'北京':{'昌平':['沙河','西二旗','西三旗'],'海淀':['圆明园']}, '河北':{'石家庄':['新华区'],'衡水':['老白干']},'广州':{'深圳':['华强北']}}
 # for index in dic.items():
 #     print(index)
 #一级菜单
 def menu_1():
     dic_01={}
     while True:
         print('一级菜单'.center(55,'#'))
         for index,menu_name in enumerate(dic):
             print(index,menu_name)
             dic_01.setdefault(index,menu_name)
         print(dic_01)
         chose = input('输入菜单序号进入下级菜单，输入b反回上一级菜单')
         if chose.isdigit():
             chose = int(chose)
             if dic_01.get(chose) == None:
                 print('没有这%s这个菜单项，请重新输入！'%chose)
                 continue
             else:
                 #print(dic_01.get(chose))
                 menu_2(dic_01.get(chose))
         elif chose == 'q':
             print("程序退出")
         else:
             print("您的输入有误，请重新输入！")

 #二级菜单
 def menu_2(name):
     dic_2 = {}
     while True:
         flag = False
         print("%s 二级菜单".center(55,'#')%name)
         for index,menu in enumerate(dic[name]):
             print(index,menu)
             dic_2.setdefault(index,menu)
         print(dic_2)
         chose2 = input('输入菜单序号进入下级菜单，输入b反回上一级菜单，输入q退出')
         if chose2.isdigit():            #判断用户输入的内容是否是数字样式
             chose2 = int(chose2)
             #print(dic_2.get(chose2))
             if dic_2.get(chose2) == None:
                 print('没有这%s这个菜单项，请重新输入！'%chose2)
             else:
                 print(dic_2.get(chose2))
                 flag = menu_3(name,dic_2.get(chose2))
                 if flag:
                     return True
                 else:
                     continue
         elif chose2 == 'q':         #用户输入‘q'则退出程序
             print("程序退出")
         elif chose2 == 'b':         #用户输入'b'则反回上级菜单
             break
         else:
             print("您的输入有误，请重新输入！")

 #三级菜单
 def menu_3(name1,name2):
     dic_3 ={}
     while True:
         print('%s 三级菜单'.center(55,'#')%name2)
         for index3,menu3 in enumerate(dic[name1][name2]):
             print(menu3)
             dic_3.setdefault(index3,menu3)
         print(dic_3)
         chose3 = input('输入b反回上一级菜单,输入m反回主菜单，输入q退出')
         if chose3 == 'q':
             print("程序退出")
             exit()
         elif chose3 == 'm':
             return True
         elif chose3 == 'b':
             return False
         else:
             print("您的输入有误，请重新输入！")

 while True:
     menu_1()

三级菜单

 dic = {'北京':{'昌平':{'沙河':{},'回龙观':{},'巩华城':{}},
                '海淀':{'圆明园'}},
        '河北':{'石家庄':{'新华区'},
                '衡水':{'老白干'}},
        '广州':{'深圳':{'华强北'}}}
 dic1 = dic
 parent_list=[]
 while True:
     for i in dic1:
         print(i)
     choose = input('>>>').strip()
     if len(choose)==0:continue
     if choose in dic1:
         parent_list.append(dic1)
         dic1 = dic1[choose]
     elif choose == 'b':
         if parent_list:
             dic1 = parent_list.pop()
     else:
         print("无此项")

三级菜单进化版