Python 实例3—三级菜单

老男孩培训学习：

 '''
 Author:Ranxf
 '''
 menu = {
     '北京': {
         '海淀': {
             '五道口': {
                 'soho': {},
                 '网易': {},
                 'google': {}
             },
             '中关村': {
                 '爱奇艺': {},
                 '汽车之家': {},
                 'youku': {},
             },
             '上地': {
                 '百度': {},
             },
         },
         '昌平': {
             '沙河': {
                 '老男孩': {},
                 '北航': {},
             },
             '天通苑': {},
             '回龙观': {},
         },
         '朝阳': {},
         '东城': {},
     },
     '上海': {
         '闵行': {
             "人民广场": {
                 '炸鸡店': {}
             }
         },
         '闸北': {
             '火车战': {
                 '携程': {}
             }
         },
         '浦东': {},
     },
     '山东': {},
 }
 exit_flag = False

 while not exit_flag:
     for i1 in menu:
         print(i1)

     choice1 = input(">>>选择一级菜单1>>>: ")
     if choice1 in menu:
         while not exit_flag:
             for i2 in menu[choice1]:
                 print("\t", i2)

             choice2 = input(">>>选择二级菜单2>>>: ")
             if choice2 in menu[choice1]:
                 while not exit_flag:
                     for i3 in menu[choice1][choice2]:
                         print("\t\t", i3)

                     choice3 = input(">>>选择三级菜单3>>>: ")
                     if choice3 in menu[choice1][choice2]:
                         for i4 in menu[choice1][choice2][choice3]:
                             print("\t\t", i4)
                         choice4 = input(">>>最后一级菜单,按b返回，按q退出>>>: ")
                         if choice4 == 'b':
                             pass
                         elif choice1 == 'q':
                             exit_flag = True

                     if choice3 == 'b':
                         break
                     elif choice3 == 'q':
                         exit_flag = True

             if choice2 == 'b':
                 break
             elif choice2 == 'q':
                     exit_flag = True
     if choice1 == 'b':
         break
     elif choice1 == 'q':
         exit_flag = True