Jarno Virtanen has a much nicer pythonization of the elisp bulk file rename script here. As he says, his looks much more Pythonic. Mine was a literal translation from an elisp semi functional approach using the same constructs.

I'll try rewriting the perl in a more perlish style later. Probably involve using foreach $f (readdir(DIR)) as an outer loop rather than trying a functional approach. Of course it's also possible to write the elisp as an imperative loop rather than in a semi functional style.

It's interesting that once I had a solution it was easy to produce a literal translation, but it didn't occur to me to recast the problem using a different approach. If I'd have started with a Python script would I have written the elsip using dolist or while?