This is a potential follow up to my earlier question

Question

This is a potential follow up to my earlier question <https flyte org slack com archives CP2HDHKE1 p1678183814829309> Are annotated `FlyteFile`s supposed to be used as input parameters of a task I have attached an example workflow in the thread where I m defining a type alias for an annotated FlyteFile with a `HashMethod` which for consistency s sake I d like to also use as the input parameter for a second task However doing so results in an error message that looks quite similar to the behavior I had described in my original post above and probably has the same cause if that s the case I m happy to provide a PR I can see why allowing annotations on both an task output and a task input may lead to weird semantics questions what function would the `HashMethod` on the input argument serve but I like the consistent typing between outputs and inputs and could see the data scientists in our org stumble across a similar problem in the future Thanks

Adrian Rumpold · Answer

Example workflow note that `HashedFile` is used as the type annotation for the argument to the `do work` task replacing it with `FlyteFile` solves the error ```from pathlib import Path from typing import Annotated from flytekit import HashMethod current context task workflow from flytekit types file import FlyteFile def hash fn ff FlyteFile gt str return ff path HashedFile = Annotated FlyteFile HashMethod hash fn task def create file gt HashedFile f = Path current context working directory data txt f write text Hello World return HashedFile str f task def do work ff HashedFile gt None print ff workflow def wf gt None data file = create file do work ff=data file if name == main wf ``` Output ```Traceback most recent call last File work mlops splat ml sandbox flyte annotated task input py line 34 in lt module gt wf File work mlops splat ml venv lib python3 9 site packages flytekit core workflow py line 263 in call return flyte entity call handler self args input kwargs File work mlops splat ml venv lib python3 9 site packages flytekit core promise py line 1093 in flyte entity call handler result = cast LocallyExecutable entity local execute child ctx kwargs File work mlops splat ml venv lib python3 9 site packages flytekit core workflow py line 282 in local execute function outputs = self execute kwargs File work mlops splat ml venv lib python3 9 site packages flytekit core workflow py line 722 in execute return exception scopes user entry point self workflow function kwargs File work mlops splat ml venv lib python3 9 site packages flytekit exceptions scopes py line 198 in user entry point return wrapped args kwargs File work mlops splat ml sandbox flyte annotated task input py line 30 in wf do work ff=data file File work mlops splat ml venv lib python3 9 site packages flytekit core base task py line 299 in call return flyte entity call handler self args kwargs type ignore File work mlops splat ml venv lib python3 9 site packages flytekit core promise py line 1085 in flyte entity call handler return cast LocallyExecutable entity local execute ctx kwargs File work mlops splat ml venv lib python3 9 site packages flytekit core base task py line 280 in local execute outputs literal map = self sandbox execute ctx input literal map File work mlops splat ml venv lib python3 9 site packages flytekit core base task py line 346 in sandbox execute return self dispatch execute ctx input literal map File work mlops splat ml venv lib python3 9 site packages flytekit core base task py line 518 in dispatch execute native inputs = TypeEngine literal map to kwargs exec ctx input literal map self python interface inputs File work mlops splat ml venv lib python3 9 site packages flytekit core type engine py line 867 in literal map to kwargs return k TypeEngine to python value ctx lm literals k python types k for k v in lm literals items File work mlops splat ml venv lib python3 9 site packages flytekit core type engine py line 867 in lt dictcomp gt return k TypeEngine to python value ctx lm literals k python types k for k v in lm literals items File work mlops splat ml venv lib python3 9 site packages flytekit core type engine py line 831 in to python value return transformer to python value ctx lv expected python type File work mlops splat ml venv lib python3 9 site packages flytekit types file file py line 417 in to python value if not issubclass expected python type FlyteFile type ignore File home adriano pyenv versions 3 9 16 lib python3 9 abc py line 123 in subclasscheck return abc subclasscheck cls subclass TypeError issubclass arg 1 must be a class``` The offending line in `file py` ```if not issubclass expected python type FlyteFile type ignore raise TypeError f Neither os PathLike nor FlyteFile specified expected python type ```

Samhita Alla · Answer

You may need to add the to the `to python value` method for this to work cc < Eduardo Apolinario eapolinario >

Eduardo Apolinario (eapolinario) · Answer

< Adrian Rumpold> this seems like a reasonable extension Feel free to open a PR should be as simple as adding to `to python value` You can link to the same and this time we can close it for good slightly smiling face

Adrian Rumpold · Answer

Sounds good I ll prepare another MR Does this warrant any documentation notes or extra test cases regarding the semantics as mentioned in the OP

Adrian Rumpold · Answer

Here s the PR <https github com flyteorg flytekit pull 1632>