• RssLibraries

Python RSS Code

Articles:

• [http://www-106.ibm.com/developerworks/webservices/library/ws-pyth11.html The PythonWeb services developer: RSS for Python]

Libraries:

• [http://www.mnot.net/python/RSS.py RSS.py] - reads most RSS versions, produces RSS 1.0

• [http://diveintomark.org/projects/feed_parser/ Feed Parser] - reads 9 RSS versions

• SpycyRoll - I don't know much about - this is an aggregator, and perhaps other stuff as well

Feed Parser

[http://diveintomark.org/projects/feed_parser/ Feed Parser] is an awesome RSS reader.

Download it, and then start a Python prompt in the same directory.

   1 import feedparser
   2 
   3 python_wiki_rss_url = "http://www.python.org/cgi-bin/moinmoin/" \
   4                       "RecentChanges?action=macro&" \
   5                       "macro=RecentChanges&do=rss_rc"
   6 
   7 feed = feedparser.parse( python_wiki_rss_url )

You now have the RSS feed data for the PythonInfo wiki!

Take a look at it; There's a lot of data there.

Of particular interest:

For each item in feed["items"], we have:

Aggregating Feeds with Feed Parser

If you're pulling down a lot of feeds, and aggregating them:

First, you probably want to use [http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/84317 Future threads] to pull down your feeds. That way, you can send out 5 requests immediately, and wait for them all to come back at once, rather than sending out a request, waiting for it to come in, send out another request, wait for it to come back in, etc., etc.,.

   1 from future import Future
   2 
   3 hit_list = [ "http://...", "...", "..." ] # list of feeds to pull down
   4 
   5 # pull down all feeds
   6 future_calls = [Future(feedparser.parse,rss_url) for rss_url in hit_list]
   7 # block until they are all in
   8 feeds = [future_obj() for future_obj in future_calls]

Now that you have your feeds, extract all the entries.

   1 entries = []
   2 for feed in feeds:
   3     entries.extend( feed[ "items" ] )

...and sort them, by SortingListsOfDictionaries:

   1 decorated = [(entry["date_parsed"], entry) for entry in entries]
   2 decorated.sort()
   3 decorated.reverse() # for most recent entries first
   4 sorted = [entry for (date,entry) in decorated]

Congradulations! You've aggregated a bunch of changes!

Contributors

LionKimbro

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