PyWikibot [1] is a Python-based framework to write bots for MediaWiki. There
are currently 2 versions of pywikibot currently used:
 - version 1.0 (also known as pywikibot-compat) is the legacy version
 - version 2.0 (also known as pywikibot-core) is a rewrite of the original
framework, focusing solely on MediaWiki wikis with an API (version 1.14 or
newer) and offering an improved internal architecture.

There are a number of scripts used by various robot operators that were used in
pywikibot-compat but have not yet been adapted to work with pywikibot-core. One
of those is commonscat.py, which allows you to add the template {{commonscat}}
(a link to a category from Wikimedia Commons) to categories. The tool works by
following the interwiki links. If the template is present on another langauge
page, the bot will use it.

You can find information about how to convert the script on [2], [3]. Patches
can be submited through the gerrit uploader [4] (you need a MediaWiki.org
account). More documentation on gerrit can be found at [5].

In order for this 
task to be considered completed, your 
patch needs to be reviewed and merged in the repository. Please allow at least 12h for this to happen.

After you have successfully claimed this task in Google Melange please do use the bug report [6] in Bugzilla for communication instead of Google Melange. This allows more PWB developers to be reached! General development questions can be asked on the Pywikibot mailing list and the #pywikipediabot IRC channel.

Students are required to read Wikimedia's general instructions first.

[1] https://www.mediawiki.org/wiki/Manual:Pywikibot
[2] https://www.mediawiki.org/wiki/Manual:Pywikibot/2.0/Conversion
[3] https://www.mediawiki.org/wiki/Manual:Pywikibot/i18n_conversion
[4] https://tools.wmflabs.org/gerrit-patch-uploader/
[5] http://www.mediawiki.org/wiki/Manual:Pywikipediabot/Gerrit