I'd also add Lua -- it's more minimalistic than Python and is often useful for embedding as a scripting language for your game (so that the players can extend it: modify the AI behavior, add custom scenarios, etc.). In fact, Lua would be my first choice for an embedded scripting language (not just) in a gamedev context.
It's also very easy to get started: http://www.lua.org/pil/
Here's a comparison: http://lua-users.org/wiki/LuaVersusPython (even though it's hosted on lua-users it points both the upsides and the downsides of both).
OTOH, if you already know Python, picking up Perl wouldn't necessarily have the highest priority (the use-cases of these substantially overlap).