socket.py 文件源码

def connect(self, host, port, timeout):
        for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC,
                                      socket.SOCK_STREAM, socket.IPPROTO_TCP,
                                      socket.AI_ADDRCONFIG):
            family, socket_type, proto, canon_name, sa = res
            sock = None
            try:
                sock = socket.socket(family, socket_type, proto)
                sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
                sock.settimeout(timeout)
                sock.connect(sa)
                return sock
            except socket.error as e:
                if sock is not None:
                    sock.close()

                if e is not None:
                    raise e
                else:
                    raise OSError('Socket: getaddrinfo returns an empty list')