Global variable Python classes

What is the proper way to define a global variable that has class scope in python?

Coming from a C/C++/Java background I assume that this is correct:

class Shape:
    lolwut = None

    def __init__(self, default=0):
        self.lolwut = default;
    def a(self):
        print self.lolwut
    def b(self):
        self.a()