<div style="margin:0px;padding:0px;border:0px;font-size:14px;line-height:inherit;font-family:helvetica,Arial,'Hiragino Sans GB','Microsoft YaHei',simsun;vertical-align:baseline;color:rgb(89,89,89);"><div class="wrap1 sclearfix" style="margin:5px auto;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-size:0px;line-height:inherit;font-family:inherit;vertical-align:baseline;width:1000px;background-color:rgb(255,255,255);"><div class="center" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><div class="container-main" style="margin:0px auto 0px 0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;float:left;width:700px;"><div class="article-detail" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;"><div class="article-content" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-size:18px;line-height:1.5;vertical-align:baseline;color:rgb(93,93,93);"><div style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:1.5;vertical-align:baseline;"><p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">你会发现，运行程序之后并且用浏览器访问 127.0.0.1:8001 ，程序会报错，浏览器
显示“该网页无法正常运作”，如下图<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">4. 释放连接TCP连接<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">若connection 模式为close，则服务器主动
关闭TCP连接，客户端被动
关闭连接，释放TCP连接；若connection 模式为keepalive，则该连接会保持一段时间，在该时间内可以继续接收请求;<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">5. 客户端浏览器解析HTML
内容<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">客户端浏览器首先解析状态行，查看表明请求是否成功的状态
代码。然后解析每
一个响应头，响应头告知以下为若干字节的HTML文档和文档的字符集。客户端浏览器读取响应数据HTML，根据HTML的语法对其进行格式化，并在浏览器窗口中
显示。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">HTTP响应报文格式：<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">这时候，在浏览器上面就可以看到正确的
页面了，并且可以调出Chrome的开发者工具查看到我们传过来的HTTP响应格式。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">根据不同的路径返回不同的
内容<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">细心的你可能会发现，现在无论我们
输出什么样的路径，只要保持 IP 和端口号不变，浏览器
页面显示的都是同样的
内容，这不太符合我们日常的使用场景。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">如果我想根据不同的路径返回不同的
内容，应该怎么办呢？<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">这时候就需要我们把服务器收到的请求报文进行解析，读取到其中的访问路径。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">观察收到的HTTP请求，会发现，它们的请求行、请求头部、请求数据是以 \r\n 进行分隔的，所以我们可以根据 \r\n 对收到的请求进行分隔，取出我们想要的访问路径。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">这时候，我们访问不同的路径，例如
http://127.0.0.1:8001/yimi/ http://127.0.0.1:8001/xiaohei/ 会在浏览器上
显示不一样的
内容<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">可以看到，我们现在的程序逻辑不是很清晰，我们可以改一下，url 用
一个列表存起来，url 对应的响应分别写成
一个个
函数，通过
函数调用进行 url 访问，你会发现，这跟某个框架的处理方式很像很像（偷笑罒ω罒~~~）<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">返回具体的 HTML
页面<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">现在，你可能会在想，目前我们想要返回的
内容是通过
函数进行返回的，返回的都是一些简单地字节，如果我想要返回
一个已经写好的精美的 HTML
页面应该怎么办呢？<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">我们可以把写好的 HTML
页面以二进制的形式读取进来，返回给浏览器，浏览器再进行解析，这就可以啦！<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">返回动态 HTML
页面<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">这时候，你可能又会纳闷，现在返回的都是些静态的、固定的 HTML
页面，如果我想返回
一个动态的 HTML
页面，应该怎么办？<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">动态的网页，本质上都是字符串的替换，字符串替换发生服务端，替换完再返回给浏览器。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">这里，我们通过返回
一个当前时间，来模拟动态 HTML
页面的返回过程。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">可以看到，现在我们每一次访问 yimi
页面，都会返回
一个当前时间。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">小结一下<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">1. web 框架的本质:<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">socket 服务端 与 浏览器的通信<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">2. socket 服务端
功能划分:<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">a. 负责与浏览器收发消息( socket 通信) --> w
sgiref/uW
sgi/gunicorn...<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">b. 根据
用户访问不同的路径执行不同的
函数<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">c. 从 HTML 读取出内容,并且完成字符串的替换 --> jinja2 (模板语言)<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">3. Python 中 Web 框架的
分类:<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">1. 按上面三个
功能划分:<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">1. 框架自带 a,b,c --> Tornado<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">2. 框架自带 b 和 c,使用第三方的 a --> <span style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:700;line-height:inherit;font-family:inherit;vertical-align:baseline;">Django<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">3. 框架自带 b,使用第三方的 a 和 c --> Flask<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">2. 按另
一个维度来划分:<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">1. Django --> 大而全(你做
一个网站能用到的它都有)<p style="margin-top:1em;margin-bottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">2. 其他 --> Flask 轻量级<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">你会发现，使用了 w
sgiref 模块之后，程序封装更好了，
代码逻辑也更加清晰了。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">下节预告<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">到了这里，相信聪明的你已经理解清楚整个 浏览器 服务器的访问过程，并且 socket 服务端
功能划分有了清晰的认知。<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">
<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">欢迎大家关注我的公众号：Python学习交流<p style="margin-top:1em;margin-b
ottom:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;line-height:inherit;font-family:inherit;vertical-align:baseline;">欢迎大家加入千人交流答疑学习基地：125240963
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