Introducing some kind of optional timeout is too involved to just drop in without significant discussion and design effort first. If you want to pursue this, please bring it up on the python-ideas mailing list.

My first take: it wouldn't really help, because nobody would use it until after it was too late ;-) So, in the absence of someone jumping on it right away, I'm closing this one too as "won't fix". If the idea gains traction, we can, of course, reopen this.

BTW, Jeffrey Friedl's book "Mastering Regular Expressions" teaches how to write bulletproof regexps. It's not always obvious at first glance, but it's an art that can be mastered.