Hi, any help would be greatly appreciated. I've been tasked with assisting upgrading Prefect 1.x code to Prefect 2, and for the most part the migration has been smooth. I have a flow that has a task that raises a LOOP signal, and I'm struggling to figure out how to properly handle/recreate this functionality in prefect 2. Is there a good way to do this same thing in Prefect 2?

raise LOOP(message=f"Status Run {n}={v_run_code}", result=dict(n=n + 1, code=v_run_code))

Hey! If you need to loop in Prefect 2 you can just write a loop using standard Python instead of raising a signal.

@Zanie in Prefect 1 I have a flow that uses LOOP signal within a task that is run as a mapped task. What would be the best option in Prefect 2? A nested loop? (I'm essentially using LOOP to dynamically spawn sequential tasks for the given mapped task)

Hm that’s a bit trickier. A loop should work though like

futures = my_task.map(range(100))
for i, future in enumerate(futures):
   if future.result() is None:
      my_task.submit(future, i + 1)

The use case is essentially API pagination. We map over a set of IDs, each mapped task run then paginates over api calls until a stop condition is achieved. Using LOOP, each individual API call can be retried using the standard prefect machinery

I think in the current world that would be best implemented with concurrent subflows (for each id) then a loop executing the tasks