how do I change Instance inernal variables, so that they ma be used by the class internal functions?

change_instance_variables.py

class Classe():
    
    def __init__(self):
        
        Classe.var1 = 10
        Classe.var2 = 3
        
    def printClasse(self):
        
        print 'multiply = ' + str(Classe.var1*Classe.var2)
        

class_instance = Classe()

class_instance.printClasse() # shows 30, ok

class_instance.var1 = 20

class_instance.printClasse() # shows 30, not 60!