Non blocking file reader for python asyncio

lefinale.py

import asyncio
import sys
import os

LOOP = asyncio.get_event_loop()


class AsyncFile:
    def __init__(self, filename):
        self.filename = filename

    async def __aenter__(self):
        self._fileno = os.open(self.filename, os.O_NONBLOCK | os.O_RDONLY)
        return self

    async def __aexit__(self, type, value, traceback):
        os.close(self._fileno)

    async def __aiter__(self):
        return self

    async def __anext__(self):
        result = None
        is_readed = asyncio.Event()

        def do_read(*_):
            nonlocal result
            result = os.read(self._fileno, 2147483647)
            LOOP.remove_reader(self._fileno)
            is_readed.set()

        LOOP.add_reader(self._fileno, do_read)
        await is_readed.wait()

        if not result:
            raise StopAsyncIteration()
        else:
            return result

async def print_all(filename):
    le_finale = False
    while not le_finale:
        print("Starting reader for", filename)
        async with AsyncFile(filename) as f:
            async for chunk in f:
                print(filename, chunk)
        print("Finishing reader for", filename)


LOOP.run_until_complete(asyncio.wait([print_all(f) for f in sys.argv[1:]]))