Ben Fry & Allison Parrish 
Getting Started with Processing.py [PDF ebook] 
Making Interactive Graphics with Processing’s Python Mode

Processing opened up the world of programming to artists, designers, educators, and beginners. The Processing.py Python implementation of Processing reinterprets it for today’s web. This short book gently introduces the core concepts of computer programming and working with Processing. Written by the co-founders of the Processing project, Reas and Fry, along with co-author Allison Parrish, Getting Started with Processing.py is your fast track to using Python’s Processing mode.