Async vs sync inner function closure behavior in Python

astinkio.py

import asyncio
from concurrent.futures import Future, ThreadPoolExecutor
import time


def sync_main() -> None:
    futures = list[Future[int]]()

    with ThreadPoolExecutor() as xtor:
        for outer_n in [4, 3, 2, 1]:
            def wait_and_return() -> int:
                inner_n = outer_n
                time.sleep(inner_n)
                return inner_n

            future = xtor.submit(wait_and_return)
            futures.append(future)

    print([future.result() for future in futures])

sync_main()
# [4, 3, 2, 1]


async def async_main() -> None:
    tasks = list[asyncio.Task[int]]()

    async with asyncio.TaskGroup() as task_group:
        for outer_n in [4, 3, 2, 1]:
            async def wait_and_return() -> int:
                inner_n = outer_n
                await asyncio.sleep(inner_n)
                return inner_n

            task = task_group.create_task(wait_and_return())
            tasks.append(task)

    print([task.result() for task in tasks])

asyncio.run(async_main())
# [1, 1, 1, 1]