class Dog:
    a = 1 # class-level variable/field/attribute
    
    def __init__( self, a ):
        self.a = a
        # a refers to the parameter named a, which is at function level scope
        # self.a refers to a field in the object
        # Dog.a
        

d = Dog( 3 )    
print( "Class level a", Dog.a )
print( "Object level a", d.a )
print( Dog )
print( d )

d2 = Dog( 4 )    
print( "Object level a", d.a )
print( d )