When would you use asyncio.TaskGroup or asyncio.gather()?

Compares structured task ownership with ordered result aggregation and different failure behavior.

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gather() runs awaitables concurrently and returns results in the same order as its inputs. By default, one raised exception is propagated to the waiter, but other submitted tasks are not automatically cancelled just because that member failed. TaskGroup creates a structured scope: when a child fails with an unhandled non-cancellation exception, it cancels the remaining children, waits for them, and reports grouped failures when the scope exits.

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Compares structured task ownership with ordered result aggregation and different failure behavior.

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Compares structured task ownership with ordered result aggregation and different failure behavior.
gather() runs awaitables concurrently and returns results in the same order as its inputs. By default, one raised exception is propagated to the waiter, but other submitted tasks are not automatically cancelled just because that member failed. TaskGroup creates a structured scope: when a child fails with an unhandled non-cancellation exception, it cancels the remaining children, waits for them, and reports grouped failures when the scope exits.
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I use TaskGroup when the children form one operation and should not outlive the parent scope. I use when ordered aggregation fits and I deliberately want its result or exception policy. turns failures into result values, which can support itemized best effort, but only if callers cannot mistake those exceptions for successful values. The business contract decides, not API familiarity.

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Claiming gather always cancels siblings
Using return_exceptions without classifying results
Creating tasks outside the owning group

When would you use asyncio.TaskGroup or asyncio.gather()?

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