Method read_bytes

python/python3/tornado/iostream.py:403–429

Asynchronously read a number of bytes. If ``partial`` is true, data is returned as soon as we have any bytes to return (but never more than ``num_bytes``) .. versionchanged:: 4.0 Added the ``partial`` argument. The callback argument is now optional

(self, num_bytes: int, partial: bool = False)

        return future

    def read_bytes(self, num_bytes: int, partial: bool = False) -> Awaitable[bytes]:
        """Asynchronously read a number of bytes.

        If ``partial`` is true, data is returned as soon as we have
        any bytes to return (but never more than ``num_bytes``)

        .. versionchanged:: 4.0
            Added the ``partial`` argument.  The callback argument is now
            optional and a `.Future` will be returned if it is omitted.

        .. versionchanged:: 6.0

           The ``callback`` and ``streaming_callback`` arguments have
           been removed. Use the returned `.Future` (and
           ``partial=True`` for ``streaming_callback``) instead.

        """
        future = self._start_read()
        assert isinstance(num_bytes, numbers.Integral)
        self._read_bytes = num_bytes
        self._read_partial = partial
        try:
            self._try_inline_read()
        except:
            future.add_done_callback(lambda f: f.exception())
            raise
        return future

    def read_into(self, buf: bytearray, partial: bool = False) -> Awaitable[int]:
        """Asynchronously read a number of bytes.