Recently, I’ve been trying to speed up my Subversion post-commit hooks.  I have several things which are run from the hook, and the number of separate commands leads to a bunch of fork() calls (or clone(), whatever).  Several of the scripts are already Python, so I figured I’d just write the hooks themselves in Python, making it so that the python interpreter would only need to start once and allowing the separate methods to be pre-compiled python.  This should decrease overall execution time, making the end-user experience slightly better overall by decreasing the time they have to wait on the server.  We’re talking about fractions of a second, but I have some operations which bulk-create directories in SVN or otherwise cause tens or hundreds of new revisions to be created at one time (which is necessary for the way some of my integration processes work), so it actually adds up.
This is also an excuse for me to learn Python, so bear with me if the code below is horrible.  Actually, don’t bear with me – leave a comment letting me know how it should have been done. :)
