第一部分day4-三次登录实验、字符编码

#-----三次登录实验-----

 1 memu = {
 2     "陕西":{
 3         "西安市":{
 4             "新城区":["大明宫遗址","含元殿遗址","八路军办事处"],
 5             "碑林区":["安碑林博物馆","明城墙","小雁塔" ],
 6             "莲湖区":["钟鼓楼","明城墙","西安都城隍庙""西安清真大寺"],
 7             "雁塔区":["秦二世胡亥墓","大兴善寺","大雁塔","曲江池","陕西历史博物馆"],
 8             "未央区":["秦阿房宫","汉未央宫","唐大明宫"],
 9             "蓝田":["华胥故里","水陆庵","王顺山","汤峪","蓝田人遗址"]
10         },
11         "汉中市":{
12             "南郑":["红寺湖风景区","黎平国家森林公园","汉山广场"],
13             "城固":["张骞纪念馆","南沙湖风景区","桔园景区"],
14             "洋县":["开元舍利塔"],
15             "佛坪":["大坪屿风景区","佛坪县自然保护区"]
16         }
17     },
18     "重庆市":{
19         "渝中区":["解放碑","朝天门","洪崖洞","若瑟堂"],
20         "万州区":["万州大瀑布","青龙瀑布","天生城","铁峰山国家森林公园"],
21         "涪陵区":["白鹤梁","大木花谷","武陵山大裂谷","816核军工洞"],
22         "大渡口":["小南海温泉","中华美德公园","金色蛋糕梦幻王国"],
23         "江北区":["观音桥","铁山坪森林公园","金源方特科幻公园"]
24     }
25 }

 1 current_layer = memu
 2 parent_layer = []
 3 while true:
 4     for key in current_layer:
 5         print(key)
 6     choice = input(">>>:").strip()
 7     if len(choice) == 0 : continue
 8     if choice in current_layer:
 9         parent_layer.append(current_layer)
10         try:
11             if current_layer[choice]:
12                 current_layer = current_layer[choice]
13         except exception:
14             print("输入错误,请重新输入！".center(50,'-'))
15             continue
16     elif choice == 'b':
17         try:
18             if current_layer:
19                 current_layer = parent_layer.pop()
20         except exception:
21             print("已返回首页目录".center(50,'-'))
22 
23     else:
24         print("无此项目")

#-----字符编码-----

#-----中国字符编码发展-----
ascii :只能存英文和拉丁字符，一个字符占一个字符，8位
gb2312:gb 2312 标准共收录 6763 个汉字
gbk:gbk 共收入 21886 个汉字和图形符号
gb18030:gb 18030 与 gb 2312-1980 和 gbk 兼容，共收录汉字70244个

unicode:utf-32:一个字符占4个字节
unicode:utf-16:一个字符占2个字节或2个以上
unicode:utf-8:一个英文用ascii码来存储，一个中文占3个字节

#-----in python2-----
utf-8 --decode-->unicode--encode-->gbk
gbk--decode-->unicode--encode-->utf-8

#测试环境为python2,在windows 客户端（gbk编码）运行

1 a = "棒极了"
2 gbk_to_unicode = a.decode("utf-8")
3 print(a) #妫掓瀬浜
4 utf8_to_unicode = gbk_to_unicode.encode("gbk")
5 print(gbk_to_unicode) #棒极了
6 print(utf8_to_unicode)#棒极了

#-----in python3 -----
字符默认编码unicode ，文件默认编码utf-8
encode 在编码同时，会把数据转成bytes 类型
decode 在解码同时，会把数据转成字符串
b = byte = 字符类型= [0-255]