Learning Python for free

Along of my life I tried to learn different scripting lenguages and I always miss some different free books, exercicies and others... But, the most important thing is ... FOR FREE.

Finally I found different sources of information and formation and I will post it and I will upgrade this post every time that I find new free sources of pythonic knowledge.

Think Python

Think in Python is book from O'Reilly, for free. It is a very good and introductory book to learn python.

Rosalind

Rosalind as they define, it is a "platform for learning bioinformatics through problem solving".
This platform is filling a gap that exists in our formation as 'programmers' (or kind of). It is very interesting because helps us to understand how we can solve problems that usually we will have working with biological (or not) data.
If you are bio-something or simply a bored humanoid that want to learn and needs practice python, that is your web !!

Learn Python

 Learn Python that page web I didn't used because has very basic tutorials but is very interesting if you are very beginner and you are using a MS Windows operative system (I encourage you install GNU / Linux) because it has an interpreter where you will practice directly what are you learning.

Coursera

Coursera it is not a python specific platform but sometimes it offers some python courses for free and it is very interesting.
Actually, in this web are posted a lot of different courses of different fields done by university professors.
I encourage you to take a look because there are lots of interesting courses.

Obviously, when you know to write in python, a correct search in Google or some other search engine will help you a lot!