Higher level Datagram support for Asyncio

Simple wrappers that allow you to await read() from datagrams as suggested by Guido van Rossum here. I frequently found myself having to inherit from asyncio.DatagramProtocol and implement this over and over.

Design

The goal of this package is to make implementing common patterns that use datagrams simple and straight-forward while still supporting more esoteric options. This is done by taking an opinionated stance on the API that differs from parts of asyncio. For instance, rather than exposing a function like create_datagram_endpoint which supports many use-cases and has conflicting parameters, asyncio_dgram only provides three functions for creating a stream:

• connect((host, port)): Creates a datagram endpoint which can only communicate with the endpoint it connected to.
• bind((host, port)): Creates a datagram endpoint that can communicate with anyone, but must specify the destination address every time it sends.
• from_socket(sock): If the above two functions are not sufficient, then asyncio_dgram simply lets the caller setup the socket as they see fit.

Example UDP echo client and server

Following the example of asyncio documentation, here's what a UDP echo client and server would look like.

import asyncio

import asyncio_dgram

async def udp_echo_client():
    stream = await asyncio_dgram.connect(("127.0.0.1", 8888))

    await stream.send(b"Hello World!")
    data, remote_addr = await stream.recv()
    print(f"Client received: {data.decode()!r}")

    stream.close()

async def udp_echo_server():
    stream = await asyncio_dgram.bind(("127.0.0.1", 8888))

    print(f"Serving on {stream.sockname}")

    data, remote_addr = await stream.recv()
    print(f"Echoing {data.decode()!r}")
    await stream.send(data, remote_addr)

    await asyncio.sleep(0.5)
    print(f"Shutting down server")

def main():
    loop = asyncio.get_event_loop()
    loop.run_until_complete(asyncio.gather(udp_echo_server(), udp_echo_client()))

if __name__ == "__main__":
    main()