[cbm-vic-20]

Likewise, TAoCP (er, Knuth's "The Art of Computer Programming") is even _older_ than SICP, and will definitely not help with writing better professional Python programs, but is steeped in first-principles goodness. Even so, I end up turning to it every once in a while; once while figuring out some tricky allocation code, and another to see if I could find a way to skip a few steps in a piece of code that needed to run in a tight loop.

It's certainly not required reading to be a successful programmer in the 21st century, but like SICP, it offers a different way of looking at things that may help influence some of your decisions on how to build something.