请求首行；        // 请求方式 请求路径 协议和版本，例如：GET /index.html HTTP/1.1
请求头信息；      // 请求头名称:请求头内容，即为key:value格式，例如：Host:localhost
空行；           // 用来与请求体分隔开
请求体。         // GET没有请求体，只有POST有请求体。

GET /562f25980001b1b106000338.jpg HTTP/1.1
Host    img.mukewang.com
User-Agent    Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.106 Safari/537.36
Accept    image/webp,image/*,*/*;q=0.8
Referer    http://www.imooc.com/
Accept-Encoding    gzip, deflate, sdch
Accept-Language    zh-CN,zh;q=0.8

POST / HTTP1.1
Host:www.wrox.com
User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)
Content-Type:application/x-www-form-urlencoded
Content-Length:40
Connection: Keep-Alive

name=Professional%20Ajax&publisher=Wiley

状态代码有三位数字组成，第一个数字定义了响应的类别，共分五种类别:
1xx：指示信息--表示请求已接收，继续处理
2xx：成功--表示请求已被成功接收、理解、接受
3xx：重定向--要完成请求必须进行更进一步的操作
4xx：客户端错误--请求有语法错误或请求无法实现
5xx：服务器端错误--服务器未能实现合法的请求

常见状态码：

200 OK                        //客户端请求成功
400 Bad Request               //客户端请求有语法错误，不能被服务器所理解
401 Unauthorized              //请求未经授权，这个状态代码必须和WWW-Authenticate报头域一起使用 
403 Forbidden                 //服务器收到请求，但是拒绝提供服务
404 Not Found                 //请求资源不存在，eg：输入了错误的URL
500 Internal Server Error     //服务器发生不可预期的错误
503 Server Unavailable        //服务器当前不能处理客户端的请求，一段时间后可能恢复正常

GET请求

GET /books/?sex=man&name=Professional HTTP/1.1
Host: www.wrox.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6)
Gecko/20050225 Firefox/1.0.1
Connection: Keep-Alive

注意最后一行是空行
POST请求

POST / HTTP/1.1
Host: www.wrox.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6)
Gecko/20050225 Firefox/1.0.1
Content-Type: application/x-www-form-urlencoded
Content-Length: 40
Connection: Keep-Alive

name=Professional%20Ajax&publisher=Wiley

import socket

def handle_request(client):

    buf = client.recv(1024)
    client.send("HTTP/1.1 200 OK\r\n\r\n".encode("utf8"))
    client.send("h1 style=‘color:red‘>Hello, yuanh1>".encode("utf8"))

def main():

    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind((‘localhost‘,8001))
    sock.listen(5)

    while True:
        connection, address = sock.accept()
        handle_request(connection)
        connection.close()

if __name__ == ‘__main__‘:

    main()

from wsgiref.simple_server import make_server


def application(environ, start_response):
    start_response(‘200 OK‘, [(‘Content-Type‘, ‘text/html‘)])
    return [b‘h1>Hello, web!h1>‘]


httpd = make_server(‘‘, 8080, application)

print(‘Serving HTTP on port 8000...‘)
# 开始监听HTTP请求:
httpd.serve_forever()

from wsgiref.simple_server import make_server

#  request            response


from app01.views import *

from app01 import urls


def routers():

    URLpattern=urls.URLpattern

    return URLpattern


def applications(environ,start_response):

    path=environ.get("PATH_INFO")
    print("path",path)
    start_response(‘200 OK‘, [(‘Content-Type‘, ‘text/html‘),(‘Charset‘, ‘utf8‘)])

    urlpattern=routers()
    func=None

    for item in urlpattern:
        if path==item[0]:
            func=item[1]
            break

    if func:
        return [func(environ)]
    else:
        return [b"
404!

"]


    # return [b"
hello world
"]



if __name__ == ‘__main__‘:

    t=make_server("",8810,applications)
    print("server is working...")
    t.serve_forever()

from app01.views import *


URLpattern = (
    ("/login/", login),
)

import pymysql

from urllib.parse import parse_qs


def login(request):

    if request.get("REQUEST_METHOD")=="POST":
        print("+++++",request)


        #当请求方式是GET时
        # user_union,pwd_union=request.get("QUERY_STRING").split("&")
        # _,user=user_union.split("=")
        # _,pwd=pwd_union.split("=")

        # 环境变量 CONTENT_LENGTH 可能是空值 或者 值丢失
        try:
            request_body_size = int(request.get(‘CONTENT_LENGTH‘, 0))
        except (ValueError):
            request_body_size = 0
        # 当请求方式是POST时, 变量将会被放在存在域wsgi.input文件中的HTTP请求信息中, 由WSGI 服务器一起发送.
        request_body = request[‘wsgi.input‘].read(request_body_size)
        d = parse_qs(request_body)


        user=d.get(b"user")[0].decode("utf8")
        pwd=d.get(b"pwd")[0].decode("utf8")

        print("user",user,pwd)


        #连接数据库
        conn = pymysql.connect(host=‘‘,port= 3306,user = ‘root‘,passwd=‘‘,db=‘s6‘) #db：库名
        #创建游标
        cur = conn.cursor()

        SQL="select * from userinfo2 WHERE NAME =‘%s‘ AND PASSWORD =‘%s‘"%(user,pwd)

        cur.execute(SQL)

        if cur.fetchone():

            f=open("templates/backend.html","rb")

            data=f.read()
            data=(data.decode("utf8"))%user
            return data.encode("utf8")

        else:
             return b"user or pwd is wrong"


    else:
        f = open("templates/login.html", "rb")

        data = f.read()
        f.close()

        return data

import pymysql


import pymysql
#连接数据库
conn = pymysql.connect(host=‘‘,port= 3306,user = ‘root‘,passwd=‘‘,db=‘s6‘) #db：库名
#创建游标
cur = conn.cursor()

# sql=‘‘‘
# create table userinfo2(
#         id INT PRIMARY KEY ,
#         name VARCHAR(32) ,
#         password VARCHAR(32)
# )
#
# ‘‘‘
#
# cur.execute(sql)
#
# cur.executemany("insert into userinfo2 values(%s,%s,%s)", [(1,"yuan","123"),
#                                                           (2,"alex","456"),
#                                                           (3,"egon","789")])


cur.execute("select * from userinfo2 WHERE NAME=‘yuan‘ AND PASSWORD =‘123‘")
#提交
conn.commit()
#关闭指针对象
cur.close()
#关闭连接对象
conn.close()