sdks/python/apache_beam/examples/snippets/transforms/aggregation/sample.py

# coding=utf-8
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
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from __future__ import absolute_import
from __future__ import print_function


def sample_fixed_size_globally(test=None):
  # [START sample_fixed_size_globally]
  import apache_beam as beam

  with beam.Pipeline() as pipeline:
    sample = (
        pipeline
        | 'Create produce' >> beam.Create([
            '🍓 Strawberry',
            '🥕 Carrot',
            '🍆 Eggplant',
            '🍅 Tomato',
            '🥔 Potato',
        ])
        | 'Sample N elements' >> beam.combiners.Sample.FixedSizeGlobally(3)
        | beam.Map(print)
    )
    # [END sample_fixed_size_globally]
    if test:
      test(sample)


def sample_fixed_size_per_key(test=None):
  # [START sample_fixed_size_per_key]
  import apache_beam as beam

  with beam.Pipeline() as pipeline:
    samples_per_key = (
        pipeline
        | 'Create produce' >> beam.Create([
            ('spring', '🍓'),
            ('spring', '🥕'),
            ('spring', '🍆'),
            ('spring', '🍅'),
            ('summer', '🥕'),
            ('summer', '🍅'),
            ('summer', '🌽'),
            ('fall', '🥕'),
            ('fall', '🍅'),
            ('winter', '🍆'),
        ])
        | 'Samples per key' >> beam.combiners.Sample.FixedSizePerKey(3)
        | beam.Map(print)
    )
    # [END sample_fixed_size_per_key]
    if test:
      test(samples_per_key)