async_aws_boto3_client.py

import functools
import asyncio
import boto3

class AsyncBoto3Client:
    def __init__(self, *args, **kwargs):
        client = boto3.client(*args, **kwargs)
        self.__client = client

        for name in dir(client):
            if name.startswith('_'):
                continue

            func = getattr(client, name)

            if not callable(func):
                continue

            def wrapper(func, *args, **kwargs):
                return asyncio.get_running_loop().run_in_executor(
                    None, lambda: func(*args, **kwargs))

            setattr(self, name, functools.partial(wrapper, func))

async def main():
    ecs = AsyncBoto3Client('ecs')
    
    def wrap_task(task):
        async def coro(task):
            print(await task)
        return asyncio.Task(coro(task))
    
    future = asyncio.gather(
        wrap_task(ecs.list_clusters()),
        wrap_task(ecs.list_clusters()),
        wrap_task(ecs.list_clusters()),
        wrap_task(ecs.list_clusters()),
        wrap_task(ecs.list_clusters()),
        wrap_task(ecs.list_clusters()),
        wrap_task(ecs.list_clusters()),
    )

    print('feels so good')
    
    await future

asyncio.run(main())

very dirty solution