Ah yeah, unfortunately tagged outputs currently inherit the output typing
of the parent DoFn. It's a bit of a pain, since a "correct" output type
hint becomes the union of all of the possible output types of the DoFn (and
becomes really hard to scope back down for DoFns that consume specific
tagged outputs!) I looked into it *very* briefly while wrangling some type
hinting breakages, but didn't spend too much time on it given other work on
my plate. It's definitely on the list of type hinting improvements though.
On Wed, May 14, 2025 at 2:14 PM Kenneth Knowles <k...@apache.org> wrote:
> Replying to break the silence - in Java the DoFn is done according to the
> main output type, then phantom types on the output tag are used to make
> sure non-main outputs are type safe (I wouldn't expect this sort of
> technique in Python)
>
> Anyone who is more expert in Beam Python typing stuff? +Jack McCluskey
> <jrmcclus...@google.com> perhaps?
>
> Kenn
>
> On Fri, May 9, 2025 at 6:14 PM Joey Tran <joey.t...@schrodinger.com>
> wrote:
>
>> Seems like a hard problem. I suppose it could look something like:
>> ```
>> def process(self, x) -> Iterable[str | TaggedOutputs[{"numbers": int]]
>> ```
>> A little ugly...
>>
>>
>>
>> On Fri, May 9, 2025 at 6:00 PM Robert Bradshaw <rober...@waymo.com>
>> wrote:
>>
>>> Unfortunately type hints have not yet been implemented for
>>> multiple-ouput Fns (though I think perhaps Jack was looking into this?)
>>>
>>> On Fri, May 9, 2025 at 2:40 PM Joey Tran <joey.t...@schrodinger.com>
>>> wrote:
>>>
>>>> Is it to just type it based on the main output?
>>>> def process(self, x) -> str:
>>>> yield "x"
>>>> yield TaggedOutput("numbers", 5)
>>>>
>>>>
