Update python transform catalog

learning/katas/python/Core Transforms/GroupByKey/GroupByKey/task.py

@@ -27,6 +27,7 @@
 #     - group
 #     - strings
 
+# [START groupbykey]
 import apache_beam as beam
 
 with beam.Pipeline() as p:
@@ -35,3 +36,4 @@
      | beam.Map(lambda word: (word[0], word))
      | beam.GroupByKey()
      | beam.LogElements())
+# [END groupbykey]

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

@@ -0,0 +1,51 @@
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# pytype: skip-file
+# pylint:disable=line-too-long
+
+# beam-playground:
+#   name: AppromximateQuantiles
+#   description: Demonstration of ApproximateQuantiles transform usage.
+#   multifile: false
+#   default_example: false
+#   context_line: 37
+#   categories:
+#   complexity: BASIC
+#   tags:
+#     - transforms
+#     - integers
+
+
+def approximatequantiles(test=None):
+  # [START quantiles]
+  import apache_beam as beam
+
+  with beam.Pipeline() as pipeline:
+    quantiles = (
+        pipeline
+        | 'Create data' >> beam.Create(list(range(1001)))
+        | 'Compute quantiles' >> beam.ApproximateQuantiles.Globally(5)
+        | beam.Map(print))
+    # [END approximatequantiles]
+    if test:
+      test(quantiles)
+
+
+if __name__ == '__main__':
+  approximatequantiles()

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

@@ -0,0 +1,45 @@
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# pytype: skip-file
+
+import unittest
+
+import mock
+
+from apache_beam.testing.test_pipeline import TestPipeline
+from apache_beam.testing.util import assert_that, equal_to
+
+from . import approximatequantiles
+
+
+@mock.patch('apache_beam.Pipeline', TestPipeline)
+@mock.patch(
+    'apache_beam.examples.snippets.transforms.aggregation.'
+    'approximatequantiles.print',
+    lambda x: x)
+class ApproximateQuantilesTest(unittest.TestCase):
+  def test_approximatequantiles(self):
+    def check_result(quantiles):
+      assert_that(quantiles, equal_to([[0, 250, 500, 750, 1000]]))
+
+    approximatequantiles.approximatequantiles(test=check_result)
+
+
+if __name__ == '__main__':
+  unittest.main()

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

@@ -0,0 +1,51 @@
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# pytype: skip-file
+# pylint:disable=line-too-long
+
+# beam-playground:
+#   name: AppromximateUnique
+#   description: Demonstration of ApproximateUnique transform usage.
+#   multifile: false
+#   default_example: false
+#   context_line: 37
+#   categories:
+#   complexity: BASIC
+#   tags:
+#     - transforms
+#     - integers
+
+
+def approximateunique(test=None):
+  # [START approximateunique]
+  import random
+
+  import apache_beam as beam
+
+  with beam.Pipeline() as pipeline:
+    data = list(range(1000))
+    random.shuffle(data)
+    result = (
+        pipeline
+        | 'create' >> beam.Create(data)
+        | 'get_estimate' >> beam.ApproximateUnique.Globally(size=16)
+        | beam.Map(print))
+    # [END approximateunique]
+    if test:
+      test(result)

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

@@ -0,0 +1,53 @@
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+import math
+import unittest
+
+import mock
+
+import apache_beam as beam
+from apache_beam.testing.test_pipeline import TestPipeline
+from apache_beam.testing.util import assert_that, equal_to
+
+from . import approximateunique
+
+# pytype: skip-file
+
+
+@mock.patch('apache_beam.Pipeline', TestPipeline)
+@mock.patch(
+    'apache_beam.examples.snippets.transforms.aggregation.'
+    'approximateunique.print',
+    lambda x: x)
+class ApproximateUniqueTest(unittest.TestCase):
+  def test_approximateunique(self):
+    def check_result(approx_count):
+      actual_count = 1000
+      sample_size = 16
+      error = 2 / math.sqrt(sample_size)
+      assert_that(
+          approx_count
+          | 'compare' >> beam.FlatMap(
+              lambda x: [abs(x - actual_count) * 1.0 / actual_count <= error]),
+          equal_to([True]))
+
+    approximateunique.approximateunique(test=check_result)
+
+
+if __name__ == '__main__':
+  unittest.main()

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

@@ -0,0 +1,64 @@
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# pytype: skip-file
+# pylint:disable=line-too-long
+
+# beam-playground:
+#   name: BatchElements
+#   description: Demonstration of BatchElements transform usage.
+#   multifile: false
+#   default_example: false
+#   context_line: 39
+#   categories:
+#     - Core Transforms
+#   complexity: BASIC
+#   tags:
+#     - transforms
+#     - strings
+#     - group
+
+
+def batchelements(test=None):
+  # [START batchelements]
+  import apache_beam as beam
+
+  with beam.Pipeline() as pipeline:
+    batches = (
+        pipeline
+        | 'Create produce' >> beam.Create([
+            '🍓',
+            '🥕',
+            '🍆',
+            '🍅',
+            '🥕',
+            '🍅',
+            '🌽',
+            '🥕',
+            '🍅',
+            '🍆',
+        ])
+        | beam.BatchElements(min_batch_size=3, max_batch_size=5)
+        | beam.Map(print))
+    # [END batchelements]
+    if test:
+      test(batches)
+
+
+if __name__ == '__main__':
+  batchelements()

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

@@ -0,0 +1,64 @@
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import unittest
+
+import mock
+
+import apache_beam as beam
+from apache_beam.testing.test_pipeline import TestPipeline
+from apache_beam.testing.util import assert_that, equal_to
+
+from . import batchelements
+
+
+def check_batches(actual):
+  # How the elements are grouped is not guaranteed, so we just
+  # check that all elements are lists and then count the elements
+  # to make sure none are lost.
+  all_elements_are_lists = (
+      actual
+      | 'Check type' >> beam.Map(lambda x: isinstance(x, list))
+      | 'All elements are lists' >> beam.CombineGlobally(all))
+  assert_that(all_elements_are_lists, equal_to([True]))
+
+  assert_that(
+      actual
+      | beam.FlatMap(lambda x: x)
+      | 'Count' >> beam.combiners.Count.PerElement(),
+      equal_to([('🍓', 1), ('🥕', 3), ('🍆', 2), ('🍅', 3), ('🌽', 1)]),
+      label='Check counts')
+
+
+def identity(x):
+  return x
+
+
+@mock.patch('apache_beam.Pipeline', TestPipeline)
+# pylint: disable=line-too-long
+@mock.patch(
+    'apache_beam.examples.snippets.transforms.aggregation.batchelements.print',
+    identity)
+# pylint: enable=line-too-long
+class BatchElementsTest(unittest.TestCase):
+  def test_batchelements(self):
+    batchelements.batchelements(check_batches)
+
+
+if __name__ == '__main__':
+  unittest.main()

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

@@ -0,0 +1,51 @@
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# pytype: skip-file
+# pylint:disable=line-too-long
+
+# beam-playground:
+#   name: ToList
+#   description: Demonstration of ToList transform usage.
+#   multifile: false
+#   default_example: false
+#   context_line: 37
+#   categories:
+#     - Core Transforms
+#   complexity: BASIC
+#   tags:
+#     - transforms
+
+
+def tolist(test=None):
+  # [START tolist]
+  import apache_beam as beam
+
+  with beam.Pipeline() as pipeline:
+    listed_produce = (
+        pipeline
+        | 'Create produce' >> beam.Create(['🍓', '🥕', '🍆', '🍅'])
+        | beam.combiners.ToList()
+        | beam.Map(print))
+    # [END tolist]
+    if test:
+      test(listed_produce)
+
+
+if __name__ == '__main__':
+  tolist()