There are more than 10 free eBooks available about Python:

... like "Dive into Python":

"This is a fantastic book that is also available in print. It covers everything, from installing Python and the language’s syntax, right up to web services and unit testing. This is a good book to learn from, but it’s also excellent to use a reference. I frequently find myself visiting the site! If you only read one book on this list make it this one."

other eBooks:

An Introduction to Tkinter
How to think like a Computer Scientist
The Standard Python Library
Invent Your Own Computer Games with Python
The Django Book
The Pylons Book
Data Structures and Algorithms with Object-Oriented Design Patterns in Python
Building Skills in Python
Building Skills in OO Design

Source 1: Dive into Python
Source 2: An Introduction to Tkinter
Source 3: How to think like a Computer Scientist
Source 4: The Standard Python Library
Source 5: Invent Your Own Computer Games with Python
Source 6: The Django Book
Source 7: The Pylons Book
Source 8: Data Structures and Algorithms with Object-Oriented Design Patterns in Python
Source 9: Building Skills in Python
Source 10: Building Skills in OO Design