Automatic Differentiation in 26 lines of Python

gist.github.com

Inspired by "Automatic Differentiation in 38 lines of Haskell", https://news.ycombinator.com/item?id=32879734

Funny, I find this harder to grok than the Haskell version. Haskell's static typing helps a lot.

Maybe familiarity with the languages? Though there probably is room to make this code more readable, without costing too many LOCs.