做啥网站好,网站建设设计团队,自己做网站的流程,医疗网站备案python 网络编程和其他语言都是一样的#xff0c;服务器这块步骤为#xff1a;1. 创建套接字2. 绑定地址3. 监听该描述符的所有请求4. 有新的请求到了调用accept处理请求 Python Web服务器网关接口#xff08;Python Web Server Gateway Interface#xff0c;简称“WSGI”网络编程和其他语言都是一样的服务器这块步骤为1. 创建套接字2. 绑定地址3. 监听该描述符的所有请求4. 有新的请求到了调用accept处理请求 Python Web服务器网关接口Python Web Server Gateway Interface简称“WSGI”可以保证同一个服务器响应不同应用框架的请求WSGI的出现让开发者可以将网络框架与网络服务器的选择分隔开来例如你可以使用Gunicorn或Nginx/uWSGI或Waitress服务器来运行Django、Flask或Pyramid应用。下面简单实现一个机遇WSGI协议的服务器。 import socket
from io import StringIO
import sysclass WSGIServer(object):address_family socket.AF_INETsocket_type socket.SOCK_STREAMrequest_queue_size 1def __init__(self, server_address):# Create a listening socketself.listen_socket listen_socket socket.socket(self.address_family,self.socket_type)# Allow to reuse the same addresslisten_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)# Bindlisten_socket.bind(server_address)# Activatelisten_socket.listen(self.request_queue_size)# Get server host name and porthost, port self.listen_socket.getsockname()[:2]self.server_name socket.getfqdn(host)self.server_port port# Return headers set by Web framework/Web applicationself.headers_set []定义了一个WSGIServer类并且在类的init函数完成了套接字的创建、绑定、监听等。下面实现WSGIServer的轮询检测新的连接并处理连接 def set_app(self, application):self.application applicationdef serve_forever(self):listen_socket self.listen_socketwhile True:# New client connectionself.client_connection, client_address listen_socket.accept()# Handle one request and close the client connection. Then# loop over to wait for another client connectionself.handle_one_request() 实现处理请求的函数 def handle_one_request(self):self.request_data request_data self.client_connection.recv(1024)# Print formatted request data a la curl -vprint(.join( {line}\n.format(lineline)for line in request_data.splitlines()))self.parse_request(request_data)# Construct environment dictionary using request dataenv self.get_environ()# Its time to call our application callable and get# back a result that will become HTTP response bodyresult self.application(env, self.start_response)# Construct a response and send it back to the clientself.finish_response(result) 解析请求 def parse_request(self, text):request_line text.splitlines()[0]request_line request_line.rstrip(\r\n)# Break down the request line into components(self.request_method, # GETself.path, # /helloself.request_version # HTTP/1.1) request_line.split() 返回当前服务器wsgi版本等信息 def get_environ(self):env {}
env[wsgi.version] (1, 0)env[wsgi.url_scheme] httpenv[wsgi.input] StringIO.StringIO(self.request_data)env[wsgi.errors] sys.stderrenv[wsgi.multithread] Falseenv[wsgi.multiprocess] Falseenv[wsgi.run_once] False# Required CGI variablesenv[REQUEST_METHOD] self.request_method # GETenv[PATH_INFO] self.path # /helloenv[SERVER_NAME] self.server_name # localhostenv[SERVER_PORT] str(self.server_port) # 8888return env 填写app所需的回调函数 def start_response(self, status, response_headers, exc_infoNone):# Add necessary server headersserver_headers [(Date, Tue, 31 Mar 2015 12:54:48 GMT),(Server, WSGIServer 0.2),]self.headers_set [status, response_headers server_headers]# To adhere to WSGI specification the start_response must return# a write callable. We simplicitys sake well ignore that detail# for now.# return self.finish_response 发送数据并且关闭连接 def finish_response(self, result):try:status, response_headers self.headers_setresponse HTTP/1.1 {status}\r\n.format(statusstatus)for header in response_headers:response {0}: {1}\r\n.format(*header)response \r\nfor data in result:response data# Print formatted response data a la curl -vprint(.join( {line}\n.format(lineline)for line in response.splitlines()))self.client_connection.sendall(response)finally:self.client_connection.close() 主函数和参数解析创建服务器 SERVER_ADDRESS (HOST, PORT) , 8888def make_server(server_address, application):server WSGIServer(server_address)server.set_app(application)return serverif __name__ __main__:if len(sys.argv) 2:sys.exit(Provide a WSGI application object as module:callable)app_path sys.argv[1]module, application app_path.split(:)module __import__(module)application getattr(module, application)httpd make_server(SERVER_ADDRESS, application)print(WSGIServer: Serving HTTP on port {port} ...\n.format(portPORT))httpd.serve_forever() 将上面的文件保存为webserver.py下面搭建虚拟环境并且安装Pyramid、Flask和Django等框架开发的网络应用。 $ [sudo] pip install virtualenv
$ mkdir ~/envs
$ virtualenv ~/envs/lsbaws/
$ cd ~/envs/lsbaws/
$ ls
bin include lib
$ source bin/activate
(lsbaws) $ pip install pyramid
(lsbaws) $ pip install flask
(lsbaws) $ pip install django 编写pyramidapp.py主要是调用pyramidapp接口生成app from pyramid.config import Configurator
from pyramid.response import Responsedef hello_world(request):return Response(Hello world from Pyramid!\n,content_typetext/plain,)config Configurator()
config.add_route(hello, /hello)
config.add_view(hello_world, route_namehello)
app config.make_wsgi_app() 可以通过自己开发的网络服务器来启动上面的Pyramid应用。python webserver.py pyramidapp:app 同样可以创建Flask应用 from flask import Flask
from flask import Response
flask_app Flask(flaskapp)flask_app.route(/hello)
def hello_world():return Response(Hello world from Flask!\n,mimetypetext/plain)app flask_app.wsgi_app上述代码的工作原理 1 网络框架提供一个命名为application的可调用对象。2 服务器每次从HTTP客户端接收请求之后调用application。它会向可调用对象传递一个名叫environ的字典作为参数其中包含了WSGI/CGI的诸多变量以及一个名为start_response的可调用对象。3 框架/应用生成HTTP状态码以及HTTP响应报头HTTP response headers然后将二者传递至start_response等待服务器保存。此外框架/应用还将返回响应的正文。服务器将状态码、响应报头和响应正文组合成HTTP响应并返回给客户端。 可以采用多进程的方式处理多个客户端请求,将上述代码稍作修改 import errno
import os
import signal
import socketSERVER_ADDRESS (HOST, PORT) , 8888
REQUEST_QUEUE_SIZE 1024def grim_reaper(signum, frame):while True:try:pid, status os.waitpid(-1, # Wait for any child processos.WNOHANG # Do not block and return EWOULDBLOCK error)except OSError:returnif pid 0: # no more zombiesreturndef handle_request(client_connection):request client_connection.recv(1024)print(request.decode())http_response b\
HTTP/1.1 200 OKHello, World!
client_connection.sendall(http_response)def serve_forever():listen_socket socket.socket(socket.AF_INET, socket.SOCK_STREAM)listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)listen_socket.bind(SERVER_ADDRESS)listen_socket.listen(REQUEST_QUEUE_SIZE)print(Serving HTTP on port {port} ....format(portPORT))signal.signal(signal.SIGCHLD, grim_reaper)while True:try:client_connection, client_address listen_socket.accept()except IOError as e:code, msg e.args# restart accept if it was interruptedif code errno.EINTR:continueelse:raisepid os.fork()if pid 0: # childlisten_socket.close() # close child copyhandle_request(client_connection)client_connection.close()os._exit(0)else: # parentclient_connection.close() # close parent copy and loop overif __name__ __main__:serve_forever()grim_reaper 函数为捕捉子进程退出的回调函数父进程等待所有子进程退出后再退出避免僵尸进程。由于子进程退出父进程捕获到消息调用grim_reaper处理由于父进程之前阻塞在accept上捕获子进程销毁消息后父进程accept失败所以增加了errno.EINTR错误判断如果是由于信号中断导致accept失败就让父进程继续调用accept即可。 谢谢关注我的微信公众平台转载于:https://www.cnblogs.com/secondtonone1/p/7481432.html
