Python 的 socket 编程是进行网络通信的基础方式之一，它可以用来实现 TCP/UDP 服务端与客户端程序。下面我会用通俗的语言和代码例子，带你快速理解 socket 编程的基本用法和常见场景。

synchronization

TCP

server: 

server = socket(AF_INET, SOCK_STREAM)
server.bind((ip, port))
server.listen(5)
new_sock, address = server.accept()
new_sock.send(...)
new_sock.recv(...)
new_sock.close()

client: 

client = socket(AF_INET, SOCK_STREAM)
client.connect(ip, port)
client.send(...)
client.recv(...)
client.close()

UDP

server: 

server = socket(AF_INET, SOCK_DGRAM)
server.bind((ip, port))
data, address = server.recvfrom(...)
server.sendto(data, address)

client: 

client = socket(AF_INET, SOCK_DGRAM)
client.recvfrom()
client.sendto(data, address)

asynchronization

server: 

class Server(asyncore.dispatcher):

    def __init__(self, host, port):
        asyncore.dispatcher.__init__(self)
        self.create_socket(AF_INET, SOCK_STREAM)
        self.set_reuse_addr()
        self.bind((host, port))
        self.listen(5)

        def handle_accept(self):
            pair = self.accept()
            if pair is not None:
                sock, address = pair[0], pair[1]
                server_handler(sock, address)

class ServerHandler(asyncore.dispatcher):

    def __init__(self, sock, address):
        asyncore.dispatcher.__init__(sock)

    def handle_write(self):
        pass

    def handle_read(self):
        pass

    def readable(self):
        pass

    def writable(self):
        pass

    def handle_close(self):
        pass

client： 

class Client(asyncore.dispatcher):

    def __init__(self, host, port):
        asyncore.dispatcher.__init__(self)
        self.connect((host, port))

    def handle_write(self):
        pass

    def handle_read(self):
        pass

    def readable(self):
        pass

    def writable(self):
        pass

    def handle_close(self):
        pass