Class TCPClient

python/python3/tornado/tcpclient.py:198–328

A non-blocking TCP connection factory. .. versionchanged:: 5.0 The ``io_loop`` argument (deprecated since version 4.1) has been removed.

class TCPClient(object):
    """A non-blocking TCP connection factory.

    .. versionchanged:: 5.0
       The ``io_loop`` argument (deprecated since version 4.1) has been removed.
    """

    def __init__(self, resolver: Optional[Resolver] = None) -> None:
        if resolver is not None:
            self.resolver = resolver
            self._own_resolver = False
        else:
            self.resolver = Resolver()
            self._own_resolver = True

    def close(self) -> None:
        if self._own_resolver:
            self.resolver.close()

    async def connect(
        self,
        host: str,
        port: int,
        af: socket.AddressFamily = socket.AF_UNSPEC,
        ssl_options: Optional[Union[Dict[str, Any], ssl.SSLContext]] = None,
        max_buffer_size: Optional[int] = None,
        source_ip: Optional[str] = None,
        source_port: Optional[int] = None,
        timeout: Optional[Union[float, datetime.timedelta]] = None,
    ) -> IOStream:
        """Connect to the given host and port.

        Asynchronously returns an `.IOStream` (or `.SSLIOStream` if
        ``ssl_options`` is not None).

        Using the ``source_ip`` kwarg, one can specify the source
        IP address to use when establishing the connection.
        In case the user needs to resolve and
        use a specific interface, it has to be handled outside
        of Tornado as this depends very much on the platform.

        Raises `TimeoutError` if the input future does not complete before
        ``timeout``, which may be specified in any form allowed by
        `.IOLoop.add_timeout` (i.e. a `datetime.timedelta` or an absolute time
        relative to `.IOLoop.time`)

        Similarly, when the user requires a certain source port, it can
        be specified using the ``source_port`` arg.

        .. versionchanged:: 4.5
           Added the ``source_ip`` and ``source_port`` arguments.

        .. versionchanged:: 5.0
           Added the ``timeout`` argument.
        """
        if timeout is not None:
            if isinstance(timeout, numbers.Real):
                timeout = IOLoop.current().time() + timeout