What is best way to learn Python for advanced developer?

[guirec.corbel at gmail.com]

Thanks for all you suggestions. The is a lot of good ressources.

The official doc - Obviously very useful;
Realpython - Seems to be good. I will try it;
Udemy - Too much courses for beginners;
Udacity - Seems to be good to see some examples for not for what I want now;
O'reilly - A little bit expensive;
Pluralsight - Seems to be good;
Lynda - I like this http://www.lynda.com/search?q=code+clinic , to view the differences between all languages. I like the idea. Very nice;
Pylint - Seems to be a good tool. I will use it;
Stromberg - I don't like the course format;

For now, I think I will try Realpython.com and Pluralsight. I will use Pylint when I will be more confident.

Thanks for your help.