Python vs. Perl, which is better to learn?

[Roy Smith]

>> * Something that encourages a different style of thinking.  [Lisp]

In that catagory, I would suggest PostScript.  Most people just think of it 
as a way to talk to printers.  What they don't realize is that it's a real 
programming language, with sophisticated flow control, data structures, 
I/O, and memory management (in addition to the graphics and typography 
support you would expect).

Now, granted, I wouldn't want to use it as a general purpose programming 
language, but if your goal is to expose yourself to different ways of 
thinking about programming, PostScript is certainly worth exploring.  And, 
it starts with a "P" :-)