While WordPress ist the most popular, Serendipity is widely acknowledged as the best.
I use it myself and can say, it has nearly every feature you want. Except the "reStructured Text or something". At least i haven't found anything yet. Writing Pythoncode in HTML is ugly, but i know nothing better.
So my advice is: http://www.s9y.org/
And not caring about the language of implementation is important, since it's PHP ;)
One thing I realize now is that software that supports XMLRPC (or better Atom) posting can support whatever client-side rendering I want (but not editing, which is OK). So I could compose in reST, then have something that renders to to HTML and uploads it as a post. Which is good enough for me (though I also hope that at least something reasonable is available for commenters -- seeing how hard it is to talk about code in the Radio commenting environments shows how difficult that can make things).
I wrote a little script to post comments to my wordpress blog from emacs (or whatever editor you might use), except that I used textile as a text formatter. I imagine there's a python module for rest, so you should be able to use it with it. Here's the URL: http://aida.homelinux.net:3050/scripts/file/wordpress/write-blog.py
If you were into any of the php solutions (wp, s9y, typo3, etc), maybe you could try GeSHI to produce a good looking python code.# k4ml
Mmmm... good point, syntax highlighting would be an excellent feature.
The features page on Serendipity doesn't mention it, but I notice on their blog that they have .html extensions and threaded comments. And a good number of interesting plugins, like GeSHI, and input plugins like Textile (which, while not my favorite, I'm sure I can adapt to). So far Serendipity is looking like the top runner.
I have tried a number of the PHP based blog software products. WordPress wins hands down. Serendipity was runner up, but it just does not have the large community behind it making it better and better.