GildedRose-Refactoring-Kata/.venv/lib/python3.12/site-packages/mrjob/examples/mr_wc.py
2025-06-22 13:36:01 +05:30

48 lines
1.5 KiB
Python

# Copyright 2009-2010 Yelp
#
# Licensed 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.
"""An implementation of wc as an MRJob.
This is meant as an example of why mapper_final is useful."""
from mrjob.job import MRJob
class MRWordCountUtility(MRJob):
def __init__(self, *args, **kwargs):
super(MRWordCountUtility, self).__init__(*args, **kwargs)
self.chars = 0
self.words = 0
self.lines = 0
def mapper(self, _, line):
# Don't actually yield anything for each line. Instead, collect them
# and yield the sums when all lines have been processed. The results
# will be collected by the reducer.
self.chars += len(line) + 1 # +1 for newline
self.words += sum(1 for word in line.split() if word.strip())
self.lines += 1
def mapper_final(self):
yield('chars', self.chars)
yield('words', self.words)
yield('lines', self.lines)
def reducer(self, key, values):
yield(key, sum(values))
if __name__ == '__main__':
MRWordCountUtility.run()