-
Notifications
You must be signed in to change notification settings - Fork 0
/
wordcount.py
107 lines (85 loc) · 3.53 KB
/
wordcount.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
#
# 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.
#
"""A word-counting workflow."""
# pytype: skip-file
# beam-playground:
# name: WordCount
# description: An example that counts words in Shakespeare's works.
# multifile: false
# pipeline_options: --output output.txt
# context_line: 44
# categories:
# - Combiners
# - Options
# - Quickstart
import argparse
import logging
import re
import apache_beam as beam
from apache_beam.io import ReadFromText
from apache_beam.io import WriteToText
from apache_beam.options.pipeline_options import PipelineOptions
from apache_beam.options.pipeline_options import SetupOptions
class WordExtractingDoFn(beam.DoFn):
"""Parse each line of input text into words."""
def process(self, element):
"""Returns an iterator over the words of this element.
The element is a line of text. If the line is blank, note that, too.
Args:
element: the element being processed
Returns:
The processed element.
"""
return re.findall(r'[\w\']+', element, re.UNICODE)
def run(argv=None, save_main_session=True):
"""Main entry point; defines and runs the wordcount pipeline."""
parser = argparse.ArgumentParser()
parser.add_argument(
'--input',
dest='input',
default='gs://dataflow-samples/shakespeare/kinglear.txt',
help='Input file to process.')
parser.add_argument(
'--output',
dest='output',
required=True,
help='Output file to write results to.')
known_args, pipeline_args = parser.parse_known_args(argv)
# We use the save_main_session option because one or more DoFn's in this
# workflow rely on global context (e.g., a module imported at module level).
pipeline_options = PipelineOptions(pipeline_args)
pipeline_options.view_as(
SetupOptions).save_main_session = save_main_session
# The pipeline will be run on exiting the with block.
with beam.Pipeline(options=pipeline_options) as p:
# Read the text file[pattern] into a PCollection.
lines = p | 'Read' >> ReadFromText(known_args.input)
counts = (
lines
| 'Split' >> (beam.ParDo(WordExtractingDoFn()).with_output_types(str))
| 'PairWithOne' >> beam.Map(lambda x: (x, 1))
| 'GroupAndSum' >> beam.CombinePerKey(sum))
# Format the counts into a PCollection of strings.
def format_result(word, count):
return '%s: %d' % (word, count)
output = counts | 'Format' >> beam.MapTuple(format_result)
# Write the output using a "Write" transform that has side effects.
# pylint: disable=expression-not-assigned
output | 'Write' >> WriteToText(known_args.output)
if __name__ == '__main__':
logging.getLogger().setLevel(logging.INFO)
run()