Python 实例3—三级菜单

老男孩培训学习：
 1 '''
 2 Author:Ranxf
 3 '''
 4 menu = {
 5     '北京': {
 6         '海淀': {
 7             '五道口': {
 8                 'soho': {},
 9                 '网易': {},
10                 'google': {}
11             },
12             '中关村': {
13                 '爱奇艺': {},
14                 '汽车之家': {},
15                 'youku': {},
16             },
17             '上地': {
18                 '百度': {},
19             },
20         },
21         '昌平': {
22             '沙河': {
23                 '老男孩': {},
24                 '北航': {},
25             },
26             '天通苑': {},
27             '回龙观': {},
28         },
29         '朝阳': {},
30         '东城': {},
31     },
32     '上海': {
33         '闵行': {
34             "人民广场": {
35                 '炸鸡店': {}
36             }
37         },
38         '闸北': {
39             '火车战': {
40                 '携程': {}
41             }
42         },
43         '浦东': {},
44     },
45     '山东': {},
46 }
47 exit_flag = False
48 
49 while not exit_flag:
50     for i1 in menu:
51         print(i1)
52 
53     choice1 = input(">>>选择一级菜单1>>>: ")
54     if choice1 in menu:
55         while not exit_flag:
56             for i2 in menu[choice1]:
57                 print("	", i2)
58 
59             choice2 = input(">>>选择二级菜单2>>>: ")
60             if choice2 in menu[choice1]:
61                 while not exit_flag:
62                     for i3 in menu[choice1][choice2]:
63                         print("		", i3)
64 
65                     choice3 = input(">>>选择三级菜单3>>>: ")
66                     if choice3 in menu[choice1][choice2]:
67                         for i4 in menu[choice1][choice2][choice3]:
68                             print("		", i4)
69                         choice4 = input(">>>最后一级菜单,按b返回，按q退出>>>: ")
70                         if choice4 == 'b':
71                             pass
72                         elif choice1 == 'q':
73                             exit_flag = True
74 
75                     if choice3 == 'b':
76                         break
77                     elif choice3 == 'q':
78                         exit_flag = True
79 
80             if choice2 == 'b':
81                 break
82             elif choice2 == 'q':
83                     exit_flag = True
84     if choice1 == 'b':
85         break
86     elif choice1 == 'q':
87         exit_flag = True