by Cathal Garvey, Copyright 2015, licensed under the GNU Affero GPL.
RSSFilter lets you take an RSS feed, apply regex queries (or custom-defined functions) to the feed, and then present the result as a new RSS feed ready for consumption by a feed reader. It has an entry point for terminal usage, and is well suited (indeed, developed for) for integration in a simple web-app relay.
I'm mulling the problem of mass-data-funnelling a lot lately and this is just one experiment as part of a much broader thing. Specifically this was inspired by the annoying discovery of a news website that provided an RSS feed for all news but not for topic-specific news. Thankfully, the topics had appropriate URL paths, so the science news could be filtered by selecting articles containing "/science/" in them. So was born RSSFilter.
Install: sudo pip install rssfilter (or sudo python3 setup.py install)
Installation gives you the rssfilter module, and also the rssfilter terminal tool.
Included in the git repo is a trivial example usage for a Flask webapp, but this is not installed with rssfilter when pip-installed or similar.
As currently written the entry-points accept up to two filters which may contain arbitrary regex expressions. As there are only two built-in filter-classes this two-filter limit isn't really a limit at all. There is an option whether to combine the given two filters by boolean AND or OR.
In module usage you can define your own filters; they should accept a feed in a format as returned by feedparser (but with all elements converted to native types!) and return one in the same format.
Fetching recent articles on the Marriage Equality referendum in Ireland (May 2015) from the Irish Times RSS feed:
rssfilter https://www.irishtimes.com/cmlink/the-irish-times-news-1.1319192 -t '([Gg]ay|[Hh]omosexual|[Mm]arriage|[Rr]eferend)'
(Use 'rssfilter --help' for more information)
Importing and using the module to achieve the same result:
import rssfilter
it_feed = "https://www.irishtimes.com/cmlink/the-irish-times-news-1.1319192"
f = rssfilter.filter_feed(it_feed, rssfilter.in_title_filter('([Gg]ay|[Hh]omosexual|[Mm]arriage|[Rr]eferend)'))
print(f)
To learn more, read the source code docstrings or use iPython to explore with the "?" appellation.