python实现http代理（含转发功能）

import re
import socket
import _thread
import os
import re
import os.path

class Proxy:
    def __init__(self):  # 我们要设置一个初始套接字等待客户端的连
        self.recv_client = None
        self.client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  # 代表基于IP地址的TCP套接字连接。
        self.client_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.client_socket.bind(("0.0.0.0", 11111));  # 手机卡绑定手机，可以接听
        self.client_socket.listen(10)  # 最多同时接10个
        self.Host = None
        self.Server_address = None

        # 初始化接听手机完毕。
        # 为什么不初始化打电话的手机呢？因为我们要收到消息之后再打出去。
    def change_coming_data(self, message):
        if os.path.exists('output.html'):
            os.remove('output.html')
        print("已删除原输出文件")
        f = open('output.html', "wb+")
        #if message.decode('utf-8').find("首页") != -1:
        print("找到要过滤的字符")
        f.write(message.decode('utf-8').replace("首页", '').encode('utf-8'))
        #os.open('output.txt', os.O_RDWR, mode=777)
        print("已写入修改新响应消息")
        f.close()
        print("已关闭新写入文件，并且读取修改完毕的内容。")
        #print(message.decode('utf-8'))
        return message

    def back_to_client(self):
        goto_html = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        goto_html.bind(("127.0.0.1", 8081))
        goto_html.listen(10)
        while True:
            conn, addr = goto_html.accept()
            msg = conn.recv(65536)
            print(conn)
            # 以字节读取数据的权限去打开html_pro.html文件
            file_html = open("output.html", "rb+")
            # 读取文件内容
            data = file_html.read()
            # 下面这句话必须写，关于http协议的内容，以后说
            #conn.sendall(bytes("HTTP/1.1 201 OK\r\n\r\n", "utf-8"))
            # 发送读取的内容
            conn.sendall(data)
            print("成功返回服务器")
            conn.close()

    def accept_client(self):
        self.recv_client, client_addr = self.client_socket.accept()
        print(client_addr)
        request = self.recv_client.recv(65536).decode('utf-8')  # 要保证在我们的接受大小之内，并且解码为字符串
        header = request.split("\r\n\r\n")[0]
        message = request.split('\r\n\r\n')[1];
        print(header)  # 消息头

        key_header = {}
        for single_header in header.split('\r\n'):
            key = single_header.split(':')[0]
            value = single_header.split(':')[1]
            if value == None:
                continue
                # 不能因为没有值就停下。
            key_header[key] = value  # 形成键值对。
        self.Host = key_header['Host']
        port = 80;

    def connect_server(self):
        server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        server_socket.ioctl(socket.SIO_KEEPALIVE_VALS, (1, 60 * 1000, 30 * 1000))
        (fam, type, _, _, server_address) = socket.getaddrinfo(self.Host.strip(), 80)[0]  # 会得到两个五元组，取第一个代表IPV4
        print(server_address)  # 解析出来的ip地址和端口
        server_socket.connect(server_address)
        while True:
            msg = "GET / HTTP/1.1\r\nhost:{}\r\nConnection: close\r\n\r\n".format(
                self.Host.strip())  # 发送构造好的信息，这里用request比较好。
            server_socket.send(msg.encode('utf-8'))
            recv_msg, address = server_socket.recvfrom(4096)
            try:
                print(recv_msg.decode('utf-8'))
            except Exception as e:
                pass

            # _thread.start_new_thread(self.accept_client)
            while input() == 'b':
                self.change_coming_data(recv_msg)
                #self.recv_client.sendall(recv_msg)
                #print("已返回服务器")
            #self.recv_client.close()
            while input() == 's':
                self.back_to_client()


    def run(self):
        while True:
            self.accept_client()
            while input() == 'a':
                self.connect_server()
    # while input() == 'b':
    # self.back_to_client()

from proxy import Proxy
def main():
    instance = Proxy();
    instance.run();

if __name__ == "__main__":
        main();