Python 3.4+Async programmingfunction

asyncio.shield()

tasks

Protects an awaitable from cancellation: if the waiter is cancelled, the inner task keeps running to completion.

Syntax

result = await asyncio.shield(aw)

Cancellation still reaches the caller: await shield(...) raises CancelledError (or TimeoutError under wait_for), only the inner task does not receive it. Pass a coroutine and shield creates a task you hold no reference to; the loop keeps tasks only by weak references, so it may be garbage-collected. Create the task yourself, keep it, and await it later.

Examples

# Python 3.11+
import asyncio
async def save():
    await asyncio.sleep(0.03)
    print('сохранено')
async def main():
    task = asyncio.create_task(save())
    try:
        await asyncio.wait_for(asyncio.shield(task), timeout=0.01)
    except TimeoutError:
        print('тайм-аут, но запись идёт')
    await task  # держим ссылку и дожидаемся
asyncio.run(main())  # → тайм-аут, но запись идёт / сохранено

See also

Common errors

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