Pygame has conducted an interview with Temple of Elemental Evil lead programmer Steve Moret about his use of Python for doing in-game scripting. A snip:
Q: What was the deciding factor to go with Python? Was it a matter of personal taste, or was there a larger comparison and analysis?
A: Coming off of Arcanum, which used an internal scripting language (an opcode based system that used a GUI tool used to select language constructs), we wanted something that could give scripters more power to do complex tasks, yet still minimize the chance of user introduced errors. In my search for this programming holy grail, I looked at Python, Small, and Lua, and finally decided upon Python because of its simple syntax, its integrated high level language constructs (tuples, classes, exceptions, and serialization), and its ease of integration into our code base. I have to admit, my prior Python experience gave it a bit of a bias, but I always say go with what you know. And we did.