Skip to main content
This is a pre-production deployment of Warehouse. Changes made here affect the production instance of PyPI (
Help us improve Python packaging - Donate today!

Pythonic in-memory MapReduce.

Project Description

Experimental Pythonic MapReduce inspired by Spotify’s luigi framework.

Canonical Word Count Example

Currently there are two MapReduce implementations, one that includes sorting and one that does not. The example below would not benefit from sorting so we can take advantage of the inherent optimization of not sorting. The API is the same but tinymr.memory.MRSerial() sorts after partitioning and again between the reducer() and final_reducer().

import json
import re
import sys

from tinymr.memory import MRSerial

class WordCount(MRSerial):

    def __init__(self):
        self.pattern = re.compile('[\W_]+')

    def mapper(self, item):
        for word in item.split():
            word = self.pattern.sub('', word)
            if word:
                yield word.lower(), 1

    def reducer(self, key, values):
        yield key, sum(values)

    def final_reducer(self, pairs):
        return {k: tuple(v)[0] for k, v in pairs}

wc = WordCount()
with open('LICENSE.txt') as f:
    out = wc(f)
    print(json.dumps(out, indent=4, sort_keys=True))

Truncated output:

    "a": 1,
    "above": 2,
    "advised": 1,
    "all": 1,
    "and": 8,
    "andor": 1


$ git clone
$ cd tinymr
$ pip install -e .\[dev\]
$ py.test tests --cov tinymr --cov-report term-missing





Release History

This version
History Node


Download Files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, Size & Hash SHA256 Hash Help File Type Python Version Upload Date
(15.1 kB) Copy SHA256 Hash SHA256
Wheel py2.py3 Sep 18, 2016
(16.8 kB) Copy SHA256 Hash SHA256
Source None Sep 18, 2016

Supported By

Elastic Elastic Search Pingdom Pingdom Monitoring Dyn Dyn DNS Sentry Sentry Error Logging CloudAMQP CloudAMQP RabbitMQ Heroku Heroku PaaS Kabu Creative Kabu Creative UX & Design Fastly Fastly CDN DigiCert DigiCert EV Certificate Google Google Cloud Servers DreamHost DreamHost Log Hosting