Assuming you already have rudimentary programming ability - I don't recommend reading a book, it takes too much time. Search for a crash course in Python, find the one that you can follow, and get a feel for the basics.
Keep a reference material at hand, so whenever you don't know how to do something, you can look it up. Stackoverflow will be your friend in this.
This way, you can start coding some test programs within a few hours, and get comfortable with the language within a few days - No need to spend too long reading a book.