Web框架
Web 框架
对于所有的Web应用，本质上其实就是一个socket服务端，用户的浏览器其实就是一个socket客户端。
实例
#!/usr/bin/env python # coding:utf-8 import socket def handle_request(client): buf = client.recv(1024) client.send("HTTP/1.1 200 OK\r\n\r\n".encode()) client.send("Hello, Seven".encode()) def main(): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.bind(('localhost', 8000)) sock.listen(5) while True: connection, address = sock.accept() handle_request(connection) connection.close() if __name__ == '__main__': main()
WSGI
WSGI（Web Server Gateway Interface）是一种规范，它定义了使用python编写的web app与web server之间接口格式，实现web app与web server间的解耦。
python标准库提供的独立WSGI服务器称为wsgiref。
from wsgiref.simple_server import make_server def RunServer(environ, start_response): start_response('200 OK', [('Content-Type', 'text/html')]) return [bytes('<h1>Hello, web!</h1>', encoding='utf-8'), ] if __name__ == '__main__': httpd = make_server('', 8000, RunServer) print("Serving HTTP on port 8000...") httpd.serve_forever()
自定义框架
实例
通过python标准库提供的wsgiref模块开发一个自己的Web框架
#!/usr/bin/env python # coding:utf-8 from wsgiref.simple_server import make_server def index(): return ['<H1>index</H1>'.encode(),] def login(): return ['<H1>login<H1>'.encode(),] def routers(): urlpatterns = ( ('/index/', index), ('/login/', login), ) return urlpatterns def RunServer(environ, start_response): start_response('200 OK', [('Content-Type', 'text/html')]) url = environ['PATH_INFO'] print(url) urlpatterns = routers() func = None for item in urlpatterns: if item[0] == url: func = item[1] break if func: return func() else: return ['404 not found'.encode(),] if __name__ == '__main__': httpd = make_server('localhost', 8000, RunServer) print("Serving HTTP on port 8000...") httpd.serve_forever()
模板替换
对于所有的login、index均返回给用户浏览器一个简单的字符串，在现实的Web请求中一般会返回一个复杂的符合HTML规则的字符串，所以我们一般将要返回给用户的HTML写在指定文件中，然后再返回。
使用开源工具jinja2，遵循其指定语法，可以实现对HTML文本替换
<!DOCTYPE html> <html> <head lang="en"> <meta charset="UTF-8"> <title></title> </head> <body> <h1>{{name}}</h1> <ul> {% for item in user_list %} <li>{{item}}</li> {% endfor %} </ul> </body> </html>
server
#!/usr/bin/env python # -*- coding:utf-8 -*- from wsgiref.simple_server import make_server from jinja2 import Template def index(): # return 'index' # template = Template('Hello {{ name }}!') # result = template.render(name='John Doe') f = open('index.html') result = f.read() template = Template(result) data = template.render(name='John Doe', user_list=['alex', 'eric']) return data.encode('utf-8') def login(): # return 'login' f = open('login.html') data = f.read() return data def routers(): urlpatterns = ( ('/index/', index), ('/login/', login), ) return urlpatterns def run_server(environ, start_response): start_response('200 OK', [('Content-Type', 'text/html')]) url = environ['PATH_INFO'] urlpatterns = routers() func = None for item in urlpatterns: if item[0] == url: func = item[1] break if func: return func() else: return '404 not found' if __name__ == '__main__': httpd = make_server('', 8000, run_server) print "Serving HTTP on port 8000..." httpd.serve_forever()
WEB框架模型
MVC‘
- Model：数据库
- View：模板文件
- Controller：业务处理
MTV
- Model：数据库
- Template：模板文件
- View：业务处理
