Dive into Python (Free)

Python is the language that powers Plone and Zope, and it's a good idea to at least know the basics of the language when developing for Plone. Dive into Python is aimed at people that have some programming language experience, but might be new to Python. The entire book is available for free online, but there is also a print version available.

The link address is: http://www.diveintopython.org