> Second, I have to ask, why would someone think that regular expressions, a tool specifically designed to search strings, would be slower than any other tool?

> Second, I have to ask, why would someone think that regular expressions, a tool specifically designed to search strings, would be slower than any other tool? Of course it's going to be the fastest! (At least in a language like Python.) I know that in Go doing string operations "manually" is almost always faster than regexps. In a quick check, about 10 times faster for this case (~120ns vs. ~1150ns for 100 chars where the last is a vowel). Of course Python is not Go, but I wouldn't actually expect simple loops in Python to be that much slower – going from "10x faster" to "2x slower" is quite a jump. Perhaps "yeah duh obvious" if you're familiar with Python and its performance characteristics, but many people aren't. Or at least I'm not. Based on my background, I wouldn't automatically expect it.