一定要懂WSGI是什么

HELLO_WORLD = b"Hello world!\n"def application(environ, start_response):

    status = '200 OK'

    response_headers = [('Content-type', 'text/plain')]

    start_response(status, response_headers)    return [HELLO_WORLD]复制代码

import socketimport sysfrom io import StringIOclass WSGIServer(object):

    address_family = socket.AF_INET

    socket_type = socket.SOCK_STREAM

    request_queue_size = 1

    def __init__(self, server_address):

        # Create a listening socket

        self.listen_socket = listen_socket = socket.socket(

            self.address_family,

            self.socket_type

        )        # Allow to reuse the same address

        listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)        # Bind

        listen_socket.bind(server_address)        # Activate

        listen_socket.listen(self.request_queue_size)        # Get server host name and port

        host, port = self.listen_socket.getsockname()[:2]

        self.server_name = socket.getfqdn(host)

        self.server_port = port        # Return headers set by Web framework/Web application

        self.headers_set = []    def set_app(self, application):

        self.application = application    def serve_forever(self):

        listen_socket = self.listen_socket        while True:            # New client connection

            self.client_connection, client_address = listen_socket.accept()            # Handle one request and close the client connection. Then

            # loop over to wait for another client connection

            self.handle_one_request()    def handle_one_request(self):

        self.request_data = request_data = self.client_connection.recv(1024)        # Print formatted request data a la 'curl -v'

        print(''.join(            '< {line}\n'.format(line=line)            for line in request_data.splitlines()

        ))

        self.parse_request(request_data)        # Construct environment dictionary using request data

        env = self.get_environ()        # It's time to call our application callable and get

        # back a result that will become HTTP response body

        result = self.application(env, self.start_response)        # Construct a response and send it back to the client

        self.finish_response(result)    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,  # GET

         self.path,  # /hello

         self.request_version  # HTTP/1.1

         ) = request_line.split()    def get_environ(self):

        env = {}        # The following code snippet does not follow PEP8 conventions

        # but it's formatted the way it is for demonstration purposes

        # to emphasize the required variables and their values

        #

        # Required WSGI variables

        env['wsgi.version'] = (1, 0)

        env['wsgi.url_scheme'] = 'http'

        env['wsgi.input'] = StringIO.StringIO(self.request_data)

        env['wsgi.errors'] = sys.stderr

        env['wsgi.multithread'] = False

        env['wsgi.multiprocess'] = False

        env['wsgi.run_once'] = False

        # Required CGI variables

        env['REQUEST_METHOD'] = self.request_method  # GET

        env['PATH_INFO'] = self.path  # /hello

        env['SERVER_NAME'] = self.server_name  # localhost

        env['SERVER_PORT'] = str(self.server_port)  # 8888

        return env    def start_response(self, status, response_headers, exc_info=None):

        # Add necessary server headers

        server_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 simplicity's sake we'll ignore that detail

        # for now.

        # return self.finish_response

    def finish_response(self, result):

        try:

            status, response_headers = self.headers_set

            response = 'HTTP/1.1 {status}\r\n'.format(status=status)            for header in response_headers:

                response += '{0}: {1}\r\n'.format(*header)

            response += '\r\n'

            for data in result:

                response += data            # Print formatted response data a la 'curl -v'

            print(''.join(                '> {line}\n'.format(line=line)                for line in response.splitlines()

            ))

            self.client_connection.sendall(response)        finally:

            self.client_connection.close()

SERVER_ADDRESS = (HOST, PORT) = 'localhost', 8080def make_server(server_address, application):

    server = WSGIServer(server_address)

    server.set_app(application)    return serverif __name__ == '__main__':

    httpd = make_server(SERVER_ADDRESS, application)

    print('WSGIServer: Serving HTTP on port {port} ...\n'.format(port=PORT))

    httpd.serve_forever()复制代码

from wsgiref.simple_server import make_server

srv = make_server('localhost', 8080, application)

srv.serve_forever()复制代码