about python advanced/new features documentation

[Kl]

Hi, python is really easy to learn in my opinion. There are loads of
tutorials/books on the web talking about the most common python features.
The problem comes when they add something new to the language or you want to
use advanced features. Since python is still evolving its difficult to find
good documentation on these new features/language changes.
Where can i find always up-to-date documentation about python? Unfortunately
the official tutorial and books become obsolete really fast.

Thanks.