parallel async python3 with timeout

parallel_async_python3_with_timeout.py

#!/usr/bin/env python3

import asyncio
from typing import List, Awaitable


async def slow_job(delay: int):
    print(f"running slow_job with {delay}s delay ...")
    await asyncio.sleep(delay)
    print(f"slow_job with {delay}s delay is done")
    if delay == 3:
        raise RuntimeError("ouch, something happened")
    return delay * 2


async def parallel(*awaitables: List[Awaitable], timeout: int = None, return_exc: bool = True):
    gathered = asyncio.gather(*awaitables, return_exceptions=return_exc)

    try:
        results = await asyncio.wait_for(gathered, timeout=timeout)
    except asyncio.TimeoutError as ex:
        try:
            raise gathered.exception()
        except asyncio.CancelledError:
            pass
        raise ex

    return results


if __name__ == "__main__":
    try:
        r1, r2, r3 = asyncio.run(parallel(
            slow_job(3),
            slow_job(1),
            slow_job(5),
            timeout=7,  # try to reduce timeout or remove it at all
            # return_exc=False,
        ))
    except asyncio.TimeoutError:
        print(f"Error: timed out")
    except Exception as ex:
        print(f"{ex.__class__.__qualname__}: {ex}")
        exit(7)

    print(f"r1: {r1!r}")
    print(f"r2: {r2!r}")
    print(f"r3: {r3!r}")