def simple_app(environ, start_response):
    """Simplest possible application object"""
    status = '200 OK'
    response_headers = [('Content-type', 'text/plain')]
    start_response(status, response_headers)
    return ['Hello World']

   def application(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/plain')])
    return ['Hello World!']

   from werkzeug.wrappers import Response

 def application(environ, start_response):
    response = Response('Hello World!', mimetype='text/plain')
    return response(environ, start_response)

   #! /usr/bin/env python

from wsgiref.simple_server import make_server

def application (environ, start_response):

    # 这里从 environ 字典中获取所有的变量值
    response_body = [
        '%s: %s' % (key, value) for key, value in sorted(environ.items())
    ]
    response_body = '\n'.join(response_body)

    status = '200 OK'
    response_headers = [
        ('Content-Type', 'text/plain'),
        ('Content-Length', str(len(response_body)))
    ]
    start_response(status, response_headers)

    return [response_body]

# 启动 WSGI  服务器
httpd = make_server (
    'localhost',
    8051,
    application # 这里指定我们的 application object)

# 开始处理请求
httpd.handle_request()

   import socket
import StringIO
import sys


class WSGIServer(object):

    address_family = socket.AF_INET
    socket_type = socket.SOCK_STREAM
    request_queue_size = 1

    def __init__(self, server_address):
        # 创建监听端口
        self.listen_socket = listen_socket = socket.socket(
            self.address_family,
            self.socket_type
        )
        listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        listen_socket.bind(server_address)
        listen_socket.listen(self.request_queue_size)
        # 获取主机名和端口信息
        host, port = self.listen_socket.getsockname()[:2]
        self.server_name = socket.getfqdn(host)
        self.server_port = port
        self.headers_set = []

    def set_app(self, application):
        self.application = application

    def serve_forever(self):
        listen_socket = self.listen_socket
        while True:
            # 处理客户端连接
            self.client_connection, client_address = listen_socket.accept()
            self.handle_one_request()

    def handle_one_request(self):
        self.request_data = request_data = self.client_connection.recv(1024)
        # 打印接收的数据
        print(''.join(
            '< {line}\n'.format(line=line)
            for line in request_data.splitlines()
        ))

        self.parse_request(request_data)

        # 使用请求的信息构造 CGI 环境变量
        env = self.get_environ()

        # 调用 WSGI callable object
        result = self.application(env, self.start_response)

        # 将结果响应给客户端
        self.finish_response(result)

    def parse_request(self, text):
        request_line = text.splitlines()[0]
        request_line = request_line.rstrip('\r\n')
        # 解析 HTTP request line
        (self.request_method,  # GET
         self.path,            # /hello
         self.request_version  # HTTP/1.1
         ) = request_line.split()

    def get_environ(self):
        # 构造响应的 WSGI 环境变量
        env = {
        		'wsgi.version': (1, 0),
        		'wsgi.url_scheme': 'http',
        		'wsgi.input': StringIO.StringIO(self.request_data),
        		'wsgi.errors': sys.stderr,
        		'wsgi.multithread': False,
        		'wsgi.run_once': False,
        		'REQUEST_METHOD': self.request_method,
        		'PATH_INFO': self.path,
        		'SERVER_NAME': self.server_name,
        		'SERVER_PORT': str(self.server_port),
        	}
        return env

    def start_response(self, status, response_headers, exc_info=None):
        # 构造响应的首部和状态码
        server_headers = [
            ('Date', 'Tue, 31 Mar 2015 12:54:48 GMT'),
            ('Server', 'WSGIServer 0.2'),
        ]
        self.headers_set = [status, response_headers + server_headers]

    def finish_response(self, result):
        try:
            status, response_headers = self.headers_set
            response = 'HTTP/1.1 {status}\n'.format(status=status)
            for header in response_headers:
                response += '{0}: {1}\n'.format(*header)
            response += '\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) = '', 8888


def make_server(server_address, application):
    server = WSGIServer(server_address)
    server.set_app(application)
    return server


if __name__ == '__main__':
    if len(sys.argv) < 2:
        sys.exit('请提供可用的wsgi应用程序, 格式为: 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(port=PORT))
    httpd.serve_forever()