Frank Yellin created BEAM-536: --------------------------------- Summary: Aggregator.py. More misleading documentation. More bad documentation Key: BEAM-536 URL: https://issues.apache.org/jira/browse/BEAM-536 Project: Beam Issue Type: Bug Reporter: Frank Yellin Priority: Minor
The last paragraph of the documentation for Aggregator is: You can also query the combined value(s) of an aggregator by calling aggregated_value() or aggregated_values() on the result object returned after running a pipeline. There are multiple problems in this one sentence! #1) There is no such method aggregated_value() that I can find anywhere. #2) DirectRunner implements aggregated_values(), but DirectPipelineRunner does not. The latter is the far more interesting case. #3) When I use a BlockingDirectPipelineRunner and ask for its aggregated_values(), I get an error message indicating that this is not implemented in DirectPipelineRunner. Very confusing since I never asked for a DirectPipelineRunner. It is clear that this is because BlockingDirectPipelineRunner is a method rather than a class. Is this really the right thing? Will there be other confusing error messages. #4) The documentation for aggregated_values() says "returns a dict of step names to values of the aggregator." I have no idea what a "step" means in this context. In practice, it seems to be a single-element dictionary whose key is 'user--' prefixed onto the aggregator name. -- This message was sent by Atlassian JIRA (v6.3.4#6332)