So I have a bunch of tasks which create and read from files. The downstream tasks in my flow don't really depend on the actual Python return value of the upstream tasks, only that the files have been created. Is there any way to explicitly declare that one task relies on another? Ideally I'd have one parameter for my flow that would be passed to each task. But if I do that out-of-the-box, then using a Dask executor each function will try to run immediately despite the necessary files not being created.

@John Jacoby you can declare these as upstream tasks by declaring them explicitly with the

upstream_tasks

keyword argument, e.g.

with Flow('my_flow') as flow:
    unrelated = unrelated_task()
    other = other_task(upstream_tasks=[unrelated])

This guarantees that

unrelated

finishes first even if

other

doesn’t need any values from it.

Thank you! I was looking for something like that in the docs.