What is wrong with the code?

[metulburr]

its not about how you refer to them...They are two completely different things. Ones a class variable and one is an instance variable.

class Klass:
    Kvar = 123
    def __init__(self):
        self.var = 456

obj1 = Klass()
obj2 = Klass()

Initial values of both

>>> print(obj1.Kvar, obj1.var)
123 456
>>> print(obj2.Kvar, obj2.var)
123 456

change class variable

>>> Klass.Kvar = 999
>>> print(obj1.Kvar, obj1.var)
999 456
>>> print(obj2.Kvar, obj2.var)
999 456

change instance variable

>>> obj1.var = 888
>>> print(obj1.Kvar, obj1.var)
999 888
>>> print(obj2.Kvar, obj2.var)
999 456

As you can see there is one class variable, all object share that, where each object has its own instance variable.