Untrusted python code

[Thomas Dybdahl Ahle]

Hi, I have an application for which I want users to be able to make 
themes.
I've planed a rather advanced model (in xml), which gives themes the 
option to redefine various drawing methods.
Now I don't want those themes to be able to take over the current user, 
but I'd still like the scripts to be able to import stuff like math.
Is there a way to ensure no IO and other dangerous stuff is done?