Python开发入门14天集训营·第2章Python 数据类型字符编码学习-3级菜单

Posted 2020-11-06 mifengwei

数据结构：

 1 menu = {
 2     ‘北京‘: {
 3         ‘海淀‘: {
 4             ‘五道口‘: {
 5                 ‘soho‘: {},
 6                 ‘网易‘: {},
 7                 ‘Google‘: {}
 8             },
 9             ‘中关村‘: {
10                 ‘爱奇艺‘: {},
11                 ‘汽车之家‘: {},
12                 ‘优酷‘: {}
13             },
14             ‘上地‘: {
15                 ‘百度‘: {},
16             },
17             },
18         ‘昌平‘: {
19             ‘沙河‘: {
20                 ‘老男孩‘: {},
21                 ‘北航‘: {},
22                 },
23             ‘通天苑‘: {},
24             ‘回龙观‘: {},
25             },
26         ‘朝阳‘: {},
27         ‘东城‘: {},
28     },
29     ‘上海‘: {
30         ‘闵行‘: {
31           ‘人民广场‘: {
32               ‘炸鸡店‘: {},
33           },
34     },
35         ‘闸北‘: {
36           ‘火车站‘: {
37               ‘携程‘: {}
38           }
39         },
40         ‘浦东‘: {},
41     },
42     ‘山东‘: {},
43 }

 

需求：
可依次选择进入各子菜单
可从任意一层往回退到上一层
可从任意一层退出程序
所需新知识点：列表、字典

low版：
不能返回上一级，直接返回最高层

 1 #!/usr/bin/env python
 2 # -*- coding=utf-8 -*-
 3 menu = {
 4     ‘北京‘: {
 5         ‘海淀‘: {
 6             ‘五道口‘: {
 7                 ‘soho‘: {},
 8                 ‘网易‘: {},
 9                 ‘Google‘: {}
10             },
11             ‘中关村‘: {
12                 ‘爱奇艺‘: {},
13                 ‘汽车之家‘: {},
14                 ‘优酷‘: {}
15             },
16             ‘上地‘: {
17                 ‘百度‘: {},
18             },
19             },
20         ‘昌平‘: {
21             ‘沙河‘: {
22                 ‘老男孩‘: {},
23                 ‘北航‘: {},
24                 },
25             ‘通天苑‘: {},
26             ‘回龙观‘: {},
27             },
28         ‘朝阳‘: {},
29         ‘东城‘: {},
30     },
31     ‘上海‘: {
32         ‘闵行‘: {
33           ‘人民广场‘: {
34               ‘炸鸡店‘: {},
35           },
36     },
37         ‘闸北‘: {
38           ‘火车站‘: {
39               ‘携程‘: {}
40           }
41         },
42         ‘浦东‘: {},
43     },
44     ‘山东‘: {},
45 }
46 exit_flag = False
47 while not exit_flag:
48     for i in menu:
49         print(i)  # 列出可查询的省份
50     province = input("请输入您要查询的省份，或按Q退出：")   # 输入需要查询的省
51     if province == ‘q‘ or province == ‘Q‘:  # 判断输入的是否是退出
52         exit_flag = True
53     elif province in menu:
54         user_province = menu[province].keys()  # 将字典中的所有键存入user_province中
55         for j in user_province:
56             print(j)
57         city = input("请输入需要查询的城市：")
58         if city in menu[province]:
59             user_city = menu[province][city].keys()
60             for k in user_city:
61                 print(k)
62             country = input("请输入需要查询的区县：")
63             if country in menu[province][city]:
64                 user_country = menu[province][city][country].keys()
65                 for v in user_country:
66                     print(v)
67             elif country == ‘q‘ or country == ‘Q‘:
68                 exit_flag = True
69             elif country == ‘t‘ or country == ‘T‘:
70                 continue
71         elif city == ‘q‘ or city == ‘Q‘:
72             exit_flag = True
73         elif city == ‘t‘ or city == ‘T‘:
74             continue

View Code

 

修改版：

 1 # -*- coding=utf-8 -*-
 2 """
 3 @author:Wllen
 4 @file:dict_3.py
 5 @time:2018/5/17 9:50
 6 """
 7 menu = {
 8     ‘北京‘: {
 9         ‘海淀‘: {
10             ‘五道口‘: {
11                 ‘soho‘: {},
12                 ‘网易‘: {},
13                 ‘Google‘: {}
14             },
15             ‘中关村‘: {
16                 ‘爱奇艺‘: {},
17                 ‘汽车之家‘: {},
18                 ‘优酷‘: {}
19             },
20             ‘上地‘: {
21                 ‘百度‘: {},
22             },
23             },
24         ‘昌平‘: {
25             ‘沙河‘: {
26                 ‘老男孩‘: {},
27                 ‘北航‘: {},
28                 },
29             ‘通天苑‘: {},
30             ‘回龙观‘: {},
31             },
32         ‘朝阳‘: {},
33         ‘东城‘: {},
34     },
35     ‘上海‘: {
36         ‘闵行‘: {
37           ‘人民广场‘: {
38               ‘炸鸡店‘: {},
39           },
40     },
41         ‘闸北‘: {
42           ‘火车站‘: {
43               ‘携程‘: {}
44           }
45         },
46         ‘浦东‘: {},
47     },
48     ‘山东‘: {},
49 }
50 list_menu = []  # 存放从字典中取得的值
51 while True:
52     if len(list_menu) == 0: # 判断list_menu中是否有值
53         user_menu = menu    # 临时字典，用于存放从menu中取得的值
54     else:
55         user_menu = list_menu[-1]   # 只要列表有值，取最后一个值
56     for i in user_menu:
57         print(i)    # 打印列表中的倒数第一个值
58     user_input = input("请输入您要查询地点，返回上一级按T，退出按Q：").strip()   # 输入需要查询的内容
59     if user_input == ‘q‘ or user_input == ‘Q‘:  # 判断输入的是否是退出q
60         break
61     if user_input == ‘t‘ or user_input == ‘T‘:  # 判断输入是否是返回上一级
62         if len(list_menu) == 0:
63             print(‘已经到顶了，没有上一级了‘)
64             continue
65         else:
66             list_menu.pop()     # 当列表不为空时，删除最后一个值，下一个循环打印出来的就是上一级菜单的内容
67             continue
68     if len(list_menu) == 0:
69         list_menu.append(user_menu[user_input])     # 列表为空时，将第一次取得的值追加到列表中
70     else:
71         list_menu.append(list_menu[-1][user_input]) # 列表不为空时，将获取的值追加到列表的最后一位

View Code