learning/katas/python/Core Transforms/Side Output/Side Output/task.py

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import apache_beam as beam
from apache_beam import pvalue

from log_elements import LogElements

num_below_100_tag = 'num_below_100'
num_above_100_tag = 'num_above_100'


class ProcessNumbersDoFn(beam.DoFn):

    def process(self, element):
        if element <= 100:
            yield element
        else:
            yield pvalue.TaggedOutput(num_above_100_tag, element)


p = beam.Pipeline()

results = \
    (p | beam.Create([10, 50, 120, 20, 200, 0])
       | beam.ParDo(ProcessNumbersDoFn())
        .with_outputs(num_above_100_tag, main=num_below_100_tag))

results[num_below_100_tag] | 'Log numbers <= 100' >> LogElements(prefix='Number <= 100: ')
results[num_above_100_tag] | 'Log numbers > 100' >> LogElements(prefix='Number > 100: ')

p.run()