Title: Writing Idiomatic Python
Author: Jeff Knupp
A small yet very useful book to teach you how to do things in a proper "Python way". It assumes you already know the language, and uses a very simple yet effective system of 1) describing the topic, 2) showing the harmful/wrong/typical way of doing it and 3) showing the idiomatic/best way to do it.
Comprehension lists, generators, choices of function arguments, default value caveats, even when to discard using objects in favor of simpler structures like named touples or just modules with functions.
Some of the examples were very revealing for me, as I come tainted from other object oriented languages and things are different in Python. You can read it in one or two afternoons so there's really no reason not to do it if you work with this programming language.
I updated my Python Gist with some notes from the book.