Scenario: I had the need for a small tool that would parse logfiles of approximately 6 million lines. To each line apply two regexps to extract a few values, and using two separate dictionaries/hashmaps (choose your poison wrt terminology) calculate how many times each capture group int he regexp shows up.
All in all, this is not going to be a very performance critical run, as it will only parse about 4 times these 6 million lines per day, so even at worst case we're talking less than 100M regexp matches per day. Piece of cake for any language. And since it's a weekend and I don't have any time when I have to deliver this finished script, I set out to prove to myself that python is going to be fast enough for this.