Correcting the pipeline object definition

[TanuSharma2511]

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[TanuSharma2511]

@liferoad

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R: @shunping for label python.

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[shunping]

Thanks for trying to clarify the concept.

However, I actually prefer the comments prior to this change, i.e. a pipeline is a DAG of PTransforms. One reason is that when we construct a pipeline in any Beam SDKs, we are explicitly putting the PTransforms together. PCollections, on the other hand, only serve as the output of one PTransform and the input of another.

[TanuSharma2511]

Thanks for your review. Isn't this contradicting here, then ?

[shunping]

If every PTransform has only one input PCollection and only one output PCollection, then it sounds also ok to say a Pipeline is a DAG of PCollections.

However, some PTransform takes multiple inputs, like Flatten. Say the input PCollections are A and B and the output of Flatten is C. It will be weird to say A,B,C are nodes, because now we have two edges A-C and B-C, and both edges represent the same Flatten Transform.

[shunping]

Thanks for your review. Isn't this contradicting here, then ?

Looks like there is inconsistency here. I checked our pipeline proto, and it also says a pipeline is a graph of PTransforms.
https://github.com/apache/beam/blob/release-2.65/model/pipeline/src/main/proto/org/apache/beam/model/pipeline/v1/beam_runner_api.proto#L80

[shunping]

here

Thanks for your review. Isn't this contradicting here, then ?

Looks like there is inconsistency here. I checked our pipeline proto, and it also says a pipeline is a graph of PTransform. https://github.com/apache/beam/blob/release-2.65/model/pipeline/src/main/proto/org/apache/beam/model/pipeline/v1/beam_runner_api.proto#L80

[shunping]

Thanks for your review. Isn't this contradicting here, then ?

Looks like there is inconsistency here. I checked our pipeline proto, and it also says a pipeline is a graph of PTransforms. https://github.com/apache/beam/blob/release-2.65/model/pipeline/src/main/proto/org/apache/beam/model/pipeline/v1/beam_runner_api.proto#L80

My appologies. I closed the PR by mistake.

Could you help modify the comment here instead? Thanks!

beam/sdks/python/apache_beam/pipeline.py

Line 122 in 5b862dd

Conceptually the :class:`~apache_beam.pvalue.PValue` s are the DAG's nodes and

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 54.54%. Comparing base (9e8e3c3) to head (f3cd157).
Report is 57 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #34899      +/-   ##
============================================
+ Coverage     54.52%   54.54%   +0.01%     
  Complexity     1479     1479              
============================================
  Files          1010     1011       +1     
  Lines        160461   160513      +52     
  Branches       1079     1079              
============================================
+ Hits          87499    87544      +45     
- Misses        70864    70871       +7     
  Partials       2098     2098              

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python	81.10% <ø> (+<0.01%)	⬆️

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[TanuSharma2511]

Run Prism_Python PreCommit 3.12

[shunping]

Just noticed two small typos in the change.

Could you correct them so we can merge the PR? Thanks!

[shunping]

LGTM. Thanks for clarifying the concepts.