using Planet Venus to split a feed?

[Dan Christensen]

I've just started reading about Planet Venus, and I'm wondering how easy
it is to use Planet Venus to split an existing feed into multiple feeds,
where the number of output feeds varies depending on the input.

In more detail, I follow the "n-category cafe", which is a blog that
provides two feeds, a main feed with the blog entries, and a comments
feed with all comments to all blog entries.  For this blog, the comments
play a major role, so I often want to read them, but I currently find
it difficult because of the volume and because the comments to different
blog entries are mixed together.

The best solution would be a feed reader that supports both mathml
and the atom threading extension in a convenient way.  For example,
I should be able to "kill" threads, mark threads as read, etc.  So
far I haven't found such a reader.  (Any suggestions?)

So instead I wrote a python program using feedparser to parse the feed
and split it, based on the subject line and other information, into
multiple output feeds.  Each time an item appears that is in a new
thread, a new feed is automatically created.  The new feed is added to
an OPML file, and my feed reader watches this file and I find the new
threads and can read them or ignore them conveniently.

My code is very rough, and now I'm wondering if Planet Venus could
do this in a cleaner, more robust way.

Thanks for any advice!

Dan