etllib

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etllib

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.. contents::

ETLlib provides functionality for munging through and repackaging JSON, TSV and other data for preparation and submission (ETL) to Apache Solr. The library takes advantage of Apache Tika, and is callable from Apache OODT.

Using ETLlib

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Installing the ETLlib package makes available four things on your computer:

repackage command The repackage command takes an original paged JSON file, strips off the paging information, isolates the identified object type (e.g., "teams" or "journal_entries", etc.), and may perform some basic cleaning and metadata addition using Apache Tika on the fields within the JSON document. poster command The poster command lets post individual reformulated JSON documents to Apache Solr. repackageandpost command The repackageandpost command combines repackage, and poster, and obviates the need to store the repackaged JSON doc as an intermediate file, and then repackages (keeps docs in memory) and then posts directly to Apache Solr. tsvtojson command Takes an input TSV file and parses it with a set of column headers and outputs a JSON file. translatejson command Takes an input JSON file and a column header file and cred file and translates from source lang to dest lang using Bing's API and Apache Tika. imagesimilarity command Computes the similarity between a directory full of image files using a feature-based approach based on Jaccard's algorithm. Clusters scores. Uses Tika.

ETLlib Library The ETLlib Library is a Python-based API for munging data and doing ETL. The library was originally developed as a set of Python scripts to be integrated into an Apache OODT ETL process through parsing/Apache Tika cleanup and then on to Apache Solr for analytics.

This document describes how to use the above three items, with special attention to the ETLlib library.

Commands

After installing the ETLlib package, new commands are made available on your system, repackage and poster and repackageandpost and tsvtojson and translatejson and imagesimiliarity..
These commands enable you to reformulate aggregate JSON documents, cleanse their fields (which may contain UTF-8 or other weird encodings), convert from different formats (e.g., TSV to JSON), translate fields within the documents using Apache Tika, and then to post those documents to Apache Solr. These were developed initially independently as python scripts that are wrapped using Apache OODT ETL workflows, but later Chris Mattmann [e-mail] decided they would be useful as a installable python library.

To use these commands from your interactive prompt, you just need to make sure your shell's PATH environment variable includes the directory where the commands are installed. On most systems, these two commands are installed in::

/usr/bin

However, on Mac OS X, the installation location may be::

/Library/Frameworks/Python.framework/Versions/Current/bin

And on Windows, it may be::

c:\Program Files\Python

Note also that some interactive shells create a cache of commands in order to execute your requests more quickly. You may need to force your shell to re-build that cache. The csh and tcsh shells are two such examples; you can make these shells rebuild their caches by running the rehash command.

Use from Shell Scripts

The repackage and poster and repackageandpost and tsvtojson and translatejson and imagesimilarity commands may be used from shell scripts as well. The only requirement for making these commands available to shell scripts is the same as for interactive sessions: the shell's PATH environment variable must include the directory that contains the commands.

Here is a sample shell script that repackages a Teams JSON file of 20 aggregate records, and outputs 20 individual Teams JSON files ::

#!/bin/bash

for ag in $(ls /data/xdata/Kiva/raw/RAW__json_teams_9Feb2013); do 
    repackage -j $ag -o teams
done

The above shell script assumes that repackage will be found in /usr/local/bin, /usr/bin, or /bin. It then loops through the aggregate teams JSON files from the Kiva raw dataset and then hands each aggregate JSON file to the repackage script, which unravels those 1234 teams JSON data files into 1234 * 20 = 24680 individual team JSON files.

The rest of the commands may also be used from a shell script.

Some example working commands are:

Pipe a single JSON journal entries file into the repackageandpost script::

echo "/data/xdata/Kiva/raw/RAW__json_journalEntries_04Mar2013/365/191677_journalentries_pg1_retreived-2013_03_04_21_56.json"
| repackageandpost -u "http://localhost:8080/solr/journalentries/update/json?commit=true" -o journal_entries -v

Take in an input TSV file named computrabajo-ve-20121108.tsv and turn it into a JSON file with a root object named employmentjobs using the provided colheaders.txt file::

tsvtojson -t data/staging/computrabajo-ve-20121108.tsv -j data/jobs/tsvtojson/1/output/computrabajo-ve-20121108.json -c conf/colheaders.txt -o employmentjobs

Extract out the ~9000 or so jobs present in computrabajo-ve-20121108.json under the "employmentjobs" key:

repackage -j ../../../../../data/jobs/tsvtojson/1/output/computrabajo-ve-20121108.json -o employmentjobs

Translate the fields defined in translate.cols in the JSON file named 648c3a4a-22d1-4a43-b0da-9c8e45716e40.json from spanish ("es") to english ("en") and output the translated JSON named 648c3a4a-22d1-4a43-b0da-9c8e45716e40-t.json, using Bing and Apache Tika and the provided credentials::

translatejson -i data/jobs/repackager/1/output/648c3a4a-22d1-4a43-b0da-9c8e45716e40.json -j data/jobs/translate/1/output/648c3a4a-22d1-4a43-b0da-9c8e45716e40-t.json -c src/tika-python/lib/translate.cols -p src/tika-python/lib/translator.creds -f es -t en -v

Compute the similarity of images in your $HOME/Pictures directory on Mac:

cd $HOME/Pictures && imagesimilarity -m -f . > similarity-scores.txt

ETLlib Library

The ETLlib Library is a Python-based application programming interface (API) for munging and processing JSON data for ETL and analytics. In fact, the commands poster and repackage and repackageandpost and tsvtojson and translatejson and imagesimilarity are implemented using the ETLlib Library. If shell-script programming is not to your taste, and you know Python, then using the ETLlib Library may be right for you.

Changelog

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0.0.2 - Refactor to use new Python-Tika lib

Current Development.

0.0.1 - Updated to include ClusterScores and Image Similarity

Includes tools to handle image similarity.

0.0.0 - Initial

This is an initial release of etllib supporting capability for reformulating JSON data using Tika_ and JSON read/write in prep for ETL using OODT_ into Solr_.

.. References: .. _OODT: http://oodt.apache.org/ .. _Tika: http://tika.apache.org/ .. _Solr: http://lucene.apache.org/solr/