anyio

import anyio async def fetch(name: str, delay: float) -> None: print(f'{name}: starting') await anyio.sleep(delay) print(f'{name}: done after {delay}s') async def main() -> None: # Task group: all tasks run concurrently; exceptions surface as ExceptionGroup async with anyio.create_task_group() as tg: tg.start_soon(fetch, 'task-A', 1.0) tg.start_soon(fetch, 'task-B', 0.5) # Timeout via CancelScope with anyio.move_on_after(2.0) as scope: await anyio.sleep(5) if scope.cancelled_caught: print('timed out (moved on)') # Run a blocking call in a thread import time result = await anyio.to_thread.run_sync(time.strftime, '%X') print('wall-clock time from thread:', result) if __name__ == '__main__': # Default backend is asyncio; swap to 'trio' with no code changes anyio.run(main, backend='asyncio')