echo.py

import asyncio

@asyncio.coroutine
def callback(reader, writer):
    while True:
        data = yield from reader.readline()
        writer.write(data)
        yield from writer.drain()

srv = asyncio.start_server(callback, '', 8000)

loop = asyncio.get_event_loop()

print ("Listen on 0.0.0.0:8000")
server = loop.run_until_complete(srv)

loop.run_forever()

Echo Serveur async en Python