class Foo():
    def __init__(self,v):
        self.v = v
    def __set_name__(self, owner, name):
        print(f'{owner.__name__} setting "{name}" to Foo({self.v})')

class Bar():
    a = Foo('1')
    b = Foo('2')
    c = Foo('3')

class Baz(Bar):
    d = Foo('4')