examples/src/python/pulsar_word_count_streamlet.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-

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'''Example WordCountStreamletTopology'''
import sys

from heronpy.streamlet.streamlet import TimeWindow
from heronpy.connectors.pulsar.pulsarstreamlet import PulsarStreamlet

# pylint: disable=superfluous-parens
if __name__ == '__main__':
  if len(sys.argv) != 4:
    print("""
    Usage: pulsar_would_count_streamlet.pex <topology_name> <pulsar_service_url> <pulsar_topic>
    """)
    sys.exit(1)

  counts = PulsarStreamlet.pulsarStreamlet(sys.argv[2], sys.argv[3], parallelism=2) \
           .flat_map(lambda line: line.split(), parallelism=2) \
           .map(lambda word: (word, 1), parallelism=2) \
           .reduce_by_window(TimeWindow(10, 2), lambda x, y: x + y)
  counts.run(sys.argv[1])