Update: Shang (5566) left in the comments that there’s another well written book at A Byte Of Python. Thanks Shang! 
Trying to learn Python but not sure where to start? I think you’ve found the right place. 
The title of this post could not be any clearer. 
This free book, “Dive Into Python”, is an excellent resource to get started and you can read it online or download it.
This book is very good and free, too. http://www.swaroopch.com/notes/Python. According to the writer it’s used as textbook for many Universities (including Harvard, somewhere not everyone of us can go), and even NASA uses it (somewhere not everyone of us knows what’s it about)
Wow! Thanks! More resource!
Totally agree on Harvard and NASA btw.
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