Paulo Costa:
> async def async_read(fd. n):

This method already exists:
* (TCP) https://docs.python.org/dev/library/asyncio-protocol.html#asyncio.Protocol.data_received
* (UDP) https://docs.python.org/dev/library/asyncio-protocol.html#asyncio.DatagramProtocol.datagram_received
* (TCP) https://docs.python.org/dev/library/asyncio-stream.html#asyncio.StreamReader.read


Martin Panter:
> last time I looked they all seemed to buffer your write data and send it in the background. E.g. in the echo-client-using-streams example, there is a writer.write() call that does not use “yield from”. Does asyncio have an easy way for a coroutine to write to a socket (or file descriptor) and block (suspend the coroutine) until the write has finished

Sure, you must call https://docs.python.org/dev/library/asyncio-stream.html#asyncio.StreamWriter.drain