用 Python 描述 Cookie 和 Session ！

2019-04-27 本文已影响0人 14e61d025165

这篇文章我们来聊聊Cookie和Session，网上有很多关于这两个知识点的描述，可惜的是大部分都没有示例代码，因此本文的重点在于示例代码。

环境

安装bottle

python学习扣qun【 1004391443】，内有安装包和学习视频资料免费分享，好友都会在里面交流，分享一些学习的方法和需要注意的小细节，每天也会准时的讲一些项目实战案例，欢迎加入

Cookie

HTTP是一种无状态协议，简单来说就是如果A第一次访问了B服务器，那么A第二次访问B服务器时，B服务器并不知道这次访问是否还是来自A。B服务器只负责接收网络信息包，传递网络信息包。这样速度很快，但是很不方便，B服务器不会记录A的数据。

为此，人们发明了Cookie，Cookie利用了HTTP中的Headers字段

<pre spellcheck="false" style="box-sizing: border-box; margin: 5px 0px; padding: 5px 10px; border: 0px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-weight: 400; font-stretch: inherit; font-size: 16px; line-height: inherit; font-family: inherit; vertical-align: baseline; cursor: text; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; background-color: rgb(240, 240, 240); border-radius: 3px; white-space: pre-wrap; color: rgb(34, 34, 34); letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">HTTP/1.1 200 OK
Date: Mon, 23 May 2005 22:38:34 GMT
Content-Type: text/html; charset=UTF-8
Content-Length: 138
Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT
Server: Apache/1.3.3.7 (Unix) (Red-Hat/Linux)
ETag: "3f80f-1b6-3e1cb03b"
Accept-Ranges: bytes
Connection: close
cookie: _zap=8aa393b0-cc62-4c6a
</pre>

现在A每次访问时都带上cookie，B服务器就可以获得A的cookie，这样B服务器就能记住一些东西

假如说我们现在要统计A一共访问了几次B服务器，我们可以编写以下代码

cookie.py

<pre spellcheck="false" style="box-sizing: border-box; margin: 5px 0px; padding: 5px 10px; border: 0px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-weight: 400; font-stretch: inherit; font-size: 16px; line-height: inherit; font-family: inherit; vertical-align: baseline; cursor: text; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; background-color: rgb(240, 240, 240); border-radius: 3px; white-space: pre-wrap; color: rgb(34, 34, 34); letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">from bottle import route, run, response, request
@route('/hello')
def hello():
count = request.get_cookie('visited')
if count:
increment = int(count) + 1
response.set_cookie('visited', str(increment))
return str(increment)
else:
response.set_cookie('visited', '0')
return 'Hello, World'
run(host='localhost', port=8080, debug=True)
</pre>

需要说明一点：在整个传输过程中传输的是字符，如果传进去一个整数，那么会报错，因此数字必须转换为字符

执行 python cookie.py

<tt-image data-tteditor-tag="tteditorTag" contenteditable="false" class="syl1556349646701 ql-align-center" data-render-status="finished" data-syl-blot="image" style="box-sizing: border-box; cursor: text; text-align: left; color: rgb(34, 34, 34); font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", "Helvetica Neue", Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: pre-wrap; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial; display: block;">

image

Session

Session一般用于登录功能，我们利用Cookie实现了有状态的传输，那么完全可以设置一个id，每次访问的时候都会带上这个id，这样B服务器就能够识别是谁访问了

一般来说，拿到id之后会存储在数据库里面，为了方便起见，在这里只存储到字典里面

session.py

<pre spellcheck="false" style="box-sizing: border-box; margin: 5px 0px; padding: 5px 10px; border: 0px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-weight: 400; font-stretch: inherit; font-size: 16px; line-height: inherit; font-family: inherit; vertical-align: baseline; cursor: text; counter-reset: list-1 0 list-2 0 list-3 0 list-4 0 list-5 0 list-6 0 list-7 0 list-8 0 list-9 0; background-color: rgb(240, 240, 240); border-radius: 3px; white-space: pre-wrap; color: rgb(34, 34, 34); letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">from bottle import route, run, response, request, redirect
login_user = {} #用来存储登录状态的字典
@route('/login')
def login():
key = hash("test password")
login_user[key] = "test password"
response.set_cookie('login', str(key))
return 'login successfuly!'
@route('/logout')
def logout():
key = request.get_cookie('login')
login_user.pop(int(key), None)
return 'logout successfuly!'
@route('/logintest')
def logintest():
key = request.get_cookie('login')
if key is not None and int(key) in login_user:
return 'login test successfuly!'
else :
return redirect('/beforelogin')
@route('/beforelogin')
def beforelogin():
return 'please login!'
run(host='localhost', port=8080, debug=True)
</pre>

执行

python session.py

<tt-image data-tteditor-tag="tteditorTag" contenteditable="false" class="syl1556349646719 ql-align-center" data-render-status="finished" data-syl-blot="image" style="box-sizing: border-box; cursor: text; text-align: left; color: rgb(34, 34, 34); font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", "Helvetica Neue", Arial, sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: pre-wrap; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial; display: block;">

image

用 Python 描述 Cookie 和 Session ！

猜你喜欢

热点阅读