WEB框架本质和套接字实现web server
http协议：规定了浏览器与服务器之间发送消息的格式。
HTTP GET请求的格式：
请求方式 路径 协议版本
请求头部
空一行
请求的数据（get可以不携带）
HTTP响应的格式：
协议版本 状态码 状态描述
响应头部（可以没有）
空一行
响应正文
Web框架的本质：
A:收发消息相关(django用wsgiref
B:根据不同URL返回不同内容
C:字符串替换
Pythonweb框架分类：
自己实现abc：tornado
自己实现bc：django
自己实现b：flask
按照另一维度分类：
运维开发：Django
后端：tornado
爬虫：flask
Socket套接字版本的web server
想要我们的web server端运行起来就必须要给客户端回复的消息符合http协议规定的格式。
import socket sk=socket.socket() sk.bind(('127.0.0.1',8080)) sk.listen() while True: conn,addr=sk.accept() data=conn.recv(1024) print(data.decode('utf-8')) conn.send(b'HTTP/1.1 200 OK/r/n/r/n<h1>hello world</h1>') conn.close()
socket套接字增强版web server
import socket server=socket.socket(socket.AF_INET,socket.SOCK_STREAM) server.bind(('127.0.0.1',8080)) server.listen(5) while True: conn,addr=server.accept() data=conn.recv(1024) data=data.decode('utf-8')#将字节类型转换为字符串 data1=data.split('\r\n')[0] url=data1.split()[1]#从浏览器发过来的消息中分离出访问路径 conn.send(b'HTTP/1.1 200 OK\r\n\r\n<strong>hello world</strong>') if url=='/index/':#根据不同url返回不同内容 response=b'index page' elif url=='/home/': response=b'home page' else: response=b'<h1>404 not found</h1>' conn.send(response) conn.close()
返回具体的HTML文件
import socket server=socket.socket(socket.AF_INET,socket.SOCK_STREAM) server.bind(('127.0.0.1',8080)) server.listen(5) def index(url): return b'<h1>welcome to index page</h1>' def home(url): return b'<h1>welcome to home page</h1>' def login(url): with open('login.html','rb') as f: return f.read() url2func=[ ('/index/',index), ('/home/',home), ('/login/',login), ] while True: conn,addr=server.accept() data=conn.recv(1024) data=data.decode('utf-8') d=data.split('\r\n')[0] url=d.split()[1] print(url) func=None for i in url2func: if url==i[0]: func=i[1] break else: func=None if func: msg=func(url) else: msg=b'<h1>404 not found</h1>' conn.send(b'HTTP/1.1 200 OK\r\n\r\n') conn.send(msg) conn.close()
返回动态HTML
import socket import time server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.bind(('127.0.0.1', 8888)) server.listen() def home(url): s = "this is {} page!".format(url) return bytes(s, encoding="utf8") def index(url): return b'<h1>index page</h1>' def user(url): # 不同的用户得到的页面上显示不同的时间 c_time = str(time.time()) with open("user.html", "r") as f: data_s = f.read() data_s = data_s.replace("@@xx@@", c_time) # 替换后的字符串数据 return bytes(data_s, encoding="utf8") def login(url): with open("login.html", "rb") as f: return f.read() # url和将要执行的函数的对应关系 url2func = [ ("/index/", index), ("/home/", home), ("/user/", user), ("/login/", login), ] while 1: conn, addr = server.accept() data = conn.recv(8096) # 收消息 # print(data) # 从浏览器发送消息中，拿到用户访问的路径 data_str = str(data, encoding="utf8") # print(data_str) url = data_str.split("\r\n")[0].split(" ")[1] print(url) func = None for i in url2func: if url == i[0]: func = i[1] # 拿到将要执行的函数 break else: func = None if func: msg = func(url) # 执行对应的函数 else: msg = b'<h1>404</h1>' # 找不到要执行的函数就返回404 # 按照HTTP协议的格式要求 回复消息 conn.send(b'HTTP/1.1 200 OK\r\n\r\n') # 发送状态行 conn.send(msg) # 发送响应体 conn.close()
WSGIREF版返回动态的HTML文件
import time from wsgiref.simple_server import make_server def home(url): return bytes('this is {} page'.format(url),encoding='utf-8') def index(url): return bytes('<h1> this is index page',encoding='utf-8') def test(url): ct=str(time.time()) with open('test.html','r') as f: data_s=f.read() data_s=data_s.replace('@@xx@@',ct) return bytes(data_s,encoding='utf8') def login(url): with open('login.html','rb') as f: return f.read() url2func=[ ('/home/',home), ('/index/',index), ('/test/',test), ('/login/',login), ] def run_server(environ,start_response): start_response('200 OK',[('Content-Type','text/html;charset=utf8'),]) url=environ['PATH_INFO'] func=None for i in url2func: if i[0]==url: func=i[1] break else: func=None if func: msg=func(url) else: msg=b'404 NOT FOUND' return [msg,] if __name__=='__main__': httpd=make_server('127.0.0.1',8080,run_server) print('8080 port') httpd.serve_forever()
jinja2版的返回动态HTML文件
from wsgiref.simple_server import make_server from jinja2 import Template import pymysql def index(url): return bytes('this is {} page'.format(url),encoding='utf8') def home(url): return b'<h1>welcome to home page</h1>' def user(url): conn=pymysql.connect( host='127.0.0.1', port=3306, user='root', password='root', database='my_system', charset='utf8', ) cursor=conn.cursor(cursor=pymysql.cursors.DictCursor) cursor.execute('select * from user') ret=cursor.fetchall() print(ret) with open('user.html','r',encoding='utf8') as f: data=f.read() template=Template(data) msg=template.render({"user_list": ret}) return bytes(msg,encoding='utf8') def login(url): with open('login.html','rb') as f: return f.read() url2func=[ ('/index/',index), ('/home/',home), ('/user/',user), ('/login/',login), ] def run_server(environ,start_response): start_response('200 OK',[('Content-Type','text/html;charset=utf8'),]) url=environ['PATH_INFO'] func=None for i in url2func: if url==i[0]: func=i[1] break else: func=None if func: msg=func(url) else: msg=b'<h1>404</h1>' return [msg,] if __name__=='__main__': httpd=make_server('127.0.0.1',8080,run_server) print('8080 port') httpd.serve_forever()
jinja2（html部分）
<table border="1"> <thead> <tr> <th>id</th> <th>name</th> <th>hobby</th> </tr> </thead> <tbody> {%for user in user_list%} <tr> <td>{{user.id}}</td> <td>{{user.name}}</td> <td>{{user.hobby}}</td> </tr> {% endfor %} </tbody> </table>
下载Django
下载版本：1.11.x
第一种方式（用pip3）：Pip3 install Django==1.11.11
第二种方式（Pycharm安装）：
Settings=>project:front_end=>project interpreter=>点击+号=>输入django=>选择版本=>勾选Specify version=>点install package
