async_utils.py

import asyncio

async def async_iterate(sync_iterable):
    """Convert a syncronized iterable into an async one.

    Taken from https://stackoverflow.com/q/76991812
    """
    # to_thread errors if StopIteration raised in it. So we use a sentinel to detect the end
    done_sentinel = object()
    it = iter(sync_iterable)
    while (value := await asyncio.to_thread(next, it, done_sentinel)) is not done_sentinel:
        yield value


def async_generator(func):
    """A decorator that converts a generator function into an async generator."""

    async def wrapper(*args, **kwargs):
        async for item in async_iterate(func(*args, **kwargs)):
            yield item

    return wrapper