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https://github.com/donnemartin/system-design-primer.git
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47 lines
1.0 KiB
Python
47 lines
1.0 KiB
Python
# -*- coding: utf-8 -*-
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from mrjob.job import MRJob
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class HitCounts(MRJob):
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def extract_url(self, line):
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"""Extract the generated url from the log line."""
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pass
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def extract_year_month(self, line):
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"""Return the year and month portions of the timestamp."""
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pass
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def mapper(self, _, line):
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"""Parse each log line, extract and transform relevant lines.
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Emit key value pairs of the form:
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(2016-01, url0), 1
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(2016-01, url0), 1
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(2016-01, url1), 1
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"""
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url = self.extract_url(line)
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period = self.extract_year_month(line)
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yield (period, url), 1
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def reducer(self, key, values):
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"""Sum values for each key.
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(2016-01, url0), 2
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(2016-01, url1), 1
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"""
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yield key, sum(values)
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def steps(self):
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"""Run the map and reduce steps."""
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return [
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self.mr(mapper=self.mapper,
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reducer=self.reducer)
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]
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if __name__ == '__main__':
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HitCounts.run()
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