Sounds good - thank you.

On Mon, Mar 30, 2020 at 11:54 AM Robert Bradshaw <[email protected]>
wrote:

> On Mon, Mar 30, 2020 at 10:40 AM Joshua B. Harrison <
> [email protected]> wrote:
>
>> Thank you for getting back to me. I would be happy to help contribute -
>> has there been any discussion around this issue before?
>>
>
> Udi has been pushing the type annotation work forward lately, though I
> don't know that he's looked into the multi-output much, if at all. It'd be
> great if you could contribute!
>
>
>> At the least, I think it be preferable to raise a not implemented error
>> in Python when encountering this case.
>>
>
> Agreed.
>
>
>> It seems like multi-input for CoGroupByKey is represented as a Union of
>> all the component collection types. Would it make sense to do the same for
>> the output types? Is this a better discussion for the dev group?
>>
>
> +1 to taking this to the dev group.
>
>
>> Thanks again for your time and help.
>>
>> Best,
>> Joshua
>>
>> On Mon, Mar 30, 2020 at 11:22 AM Robert Bradshaw <[email protected]>
>> wrote:
>>
>>> That is correct, type hints unfortunately are not yet supported for
>>> multiple-output PTransforms.
>>>
>>> On Thu, Mar 26, 2020 at 10:05 PM Joshua B. Harrison <
>>> [email protected]> wrote:
>>>
>>>> Hello all,
>>>>
>>>> I am working on adding type hints to my pipeline, and ran into an issue
>>>> with PTransforms that produce multiple, tagged outputs.
>>>>
>>>> My class looks like this:
>>>>
>>>> @with_input_types(mytype.Data)
>>>>> @with_output_types(mytype.KeyedData)
>>>>> class DenormalizeData(ptransform.PTransform):
>>>>>   MAIN = 'denormalized'
>>>>>   SKIPPED = functions.DenormalizeData.SKIPPED
>>>>>   def expand(self, pcol: mytype.Data) -> mytype.KeyedPriceData:
>>>>>     return (pcol
>>>>>       | 'Denormalize PriceData' >> core.ParDo(
>>>>>         functions.DenormalizeData()).with_outputs(
>>>>>           self.SKIPPED, main=self.MAIN))
>>>>
>>>>
>>>> Where functions.DenormalizeData is a core.DoFn. From what I can tell,
>>>> the type checking code here at
>>>> https://github.com/apache/beam/blob/master/sdks/python/apache_beam/transforms/ptransform.py#L429
>>>>  attempts
>>>> to access the pvalue._element_type. But in this case, the pvalue is a
>>>> DoOutputsTuple (
>>>> https://github.com/apache/beam/blob/master/sdks/python/apache_beam/pvalue.py#L239)
>>>> which overrides __getattr__ to check for tag names. In this case,
>>>> _element_type is not a valid tag, and I get the following partial  stack:
>>>>
>>>> "apache_beam_2_17_0/apache_beam/transforms/ptransform.py", line 401, in
>>>>> type_check_inputs_or_outputs
>>>>>     if pvalue_.element_type is None:
>>>>>   File "apache_beam_2_17_0/apache_beam/pvalue.py", line 241, in
>>>>> __getattr__
>>>>>     return self[tag]
>>>>>   File "apache_beam_2_17_0/apache_beam/pvalue.py", line 256, in
>>>>> __getitem__
>>>>>     tag, self._main_tag, self._tags))
>>>>> ValueError: Tag 'element_type' is neither the main tag 'denormalized'
>>>>> nor any of the tags ('skipped',)
>>>>
>>>>
>>>> Is my diagnoses correct? Is this a known issue? Can type hints exist on
>>>> DoOutputsTuples?
>>>>
>>>> Thank you for your time and help.
>>>>
>>>> Best,
>>>> Joshua
>>>>
>>>> --
>>>> Joshua Harrison |  Software Engineer |  [email protected]
>>>> <[email protected]> |  404-433-0242 <(404)%20433-0242>
>>>>
>>>
>>
>> --
>> Joshua Harrison |  Software Engineer |  [email protected]
>> <[email protected]> |  404-433-0242 <(404)%20433-0242>
>>
>

-- 
Joshua Harrison |  Software Engineer |  [email protected]
<[email protected]> |  404-433-0242

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