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Posted to user@beam.apache.org by "Joshua B. Harrison" <jo...@gmail.com> on 2020/03/27 05:05:02 UTC

Type hints do not work on multi-output PTransforms?

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 |  joshharrison@gmail.com
<jo...@google.com> |  404-433-0242

Re: Type hints do not work on multi-output PTransforms?

Posted by "Joshua B. Harrison" <jo...@gmail.com>.
Sounds good - thank you.

On Mon, Mar 30, 2020 at 11:54 AM Robert Bradshaw <ro...@google.com>
wrote:

> On Mon, Mar 30, 2020 at 10:40 AM Joshua B. Harrison <
> josh.harrison@gmail.com> 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 <ro...@google.com>
>> 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 <
>>> josh.harrison@gmail.com> 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 |  joshharrison@gmail.com
>>>> <jo...@google.com> |  404-433-0242 <(404)%20433-0242>
>>>>
>>>
>>
>> --
>> Joshua Harrison |  Software Engineer |  joshharrison@gmail.com
>> <jo...@google.com> |  404-433-0242 <(404)%20433-0242>
>>
>

-- 
Joshua Harrison |  Software Engineer |  joshharrison@gmail.com
<jo...@google.com> |  404-433-0242

Re: Type hints do not work on multi-output PTransforms?

Posted by Robert Bradshaw <ro...@google.com>.
On Mon, Mar 30, 2020 at 10:40 AM Joshua B. Harrison <jo...@gmail.com>
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 <ro...@google.com>
> 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 <
>> josh.harrison@gmail.com> 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 |  joshharrison@gmail.com
>>> <jo...@google.com> |  404-433-0242 <(404)%20433-0242>
>>>
>>
>
> --
> Joshua Harrison |  Software Engineer |  joshharrison@gmail.com
> <jo...@google.com> |  404-433-0242 <(404)%20433-0242>
>

Re: Type hints do not work on multi-output PTransforms?

Posted by "Joshua B. Harrison" <jo...@gmail.com>.
Thank you for getting back to me. I would be happy to help contribute - has
there been any discussion around this issue before?

At the least, I think it be preferable to raise a not implemented error in
Python when encountering this case.

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?

Thanks again for your time and help.

Best,
Joshua

On Mon, Mar 30, 2020 at 11:22 AM Robert Bradshaw <ro...@google.com>
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 <
> josh.harrison@gmail.com> 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 |  joshharrison@gmail.com
>> <jo...@google.com> |  404-433-0242 <(404)%20433-0242>
>>
>

-- 
Joshua Harrison |  Software Engineer |  joshharrison@gmail.com
<jo...@google.com> |  404-433-0242

Re: Type hints do not work on multi-output PTransforms?

Posted by Robert Bradshaw <ro...@google.com>.
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 <jo...@gmail.com>
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 |  joshharrison@gmail.com
> <jo...@google.com> |  404-433-0242 <(404)%20433-0242>
>