`from prefect import task Flow` `from typing import Tuple` `

Question

`from prefect import task Flow` `from typing import Tuple` ` task` `def double and triple x int gt Tuple int int ` `return x 2 x 3` `with Flow This works as flow ` `a = 1 2 3 ` `double triple = double and triple map x=a `

Philip MacMenamin · Answer

returns ```Traceback most recent call last File test mult ret py line 11 in lt module gt double triple = double and triple map x=a File home macmenaminpe local lib python3 8 site packages prefect core task py line 1034 in iter raise TypeError TypeError Task is not iterable If your task returns multiple results pass `nout` to the task decorator constructor or provide a `Tuple` return type annotation to your task ```

Philip MacMenamin · Answer

same if ``` task nout=2 ```

Anna Geller · Answer

nout is the right approach here But it doesn t work with mapped tasks check <https github com PrefectHQ prefect issues 4839|this open issue>

Philip MacMenamin · Answer

Is the work around to just bundle your return into an object and return that Or is there a nicer way of doing things

Philip MacMenamin · Answer

Hmm this works but I guess that extra `zip task` task might be nicer

Kevin Kho · Answer

Yeah you need to bundle it as a list or dict A `zip task` is not quite the right concept The `double and triple` task returns a `Tuple` so mapping returns a `List Tuple ` So if you map over 10 items you get 10 Tuples `x y = something` in Python means that iterable has 2 items It assumed the output type is `Tuple List `