I used to work with PHP and recently I was asking myself, whats going on with this classmethod? Python manual is very technical and very short in words so it wont help with understanding that feature. I was googling and googling and I found answer -> .

If you are lazy to click it. My explanation is shorter and below. :)

in PHP (maybe not all of you know PHP, but this language is so straight forward that everybody should understand what I'm talking about) we have static variables like this:

class A {
              static protected $inner_var = null;     static public function echoInnerVar()     {
                  echo self::$inner_var."\n";     }     static public function setInnerVar($v)     {
                  self::$inner_var = $v;     } } class B extends A {
          } A::setInnerVar(10); B::setInnerVar(20); A::echoInnerVar(); B::echoInnerVar();

The output will be in both cases 20.

However in python we can add @classmethod decorator and thus it is possible to have output 10 and 20 respectively. Example:

class A(object):     inner_var = 0     @classmethod     def setInnerVar(cls, value):         cls.inner_var = value     @classmethod     def echoInnerVar(cls):         print cls.inner_var class B(A):     pass A.setInnerVar(10) B.setInnerVar(20) A.echoInnerVar() B.echoInnerVar()

Smart, ain't?