Give class attributes knowledge about how they are used on their parent class

class_attribute_knows_its_name_on_parent_class.py

class Bar:
    def __init__(self):
        self.parent_class_attr_name = None


class LetClassAttributesKnowTheirName(type):
    def __new__(mcs, name, bases, attributes):
        for attr_name, attr_value in attributes.items():
            if isinstance(attr_value, Bar):
                attr_value.parent_class_attr_name = attr_name
        return super().__new__(mcs, name, bases, attributes)


class Foo(metaclass=LetClassAttributesKnowTheirName):
    bar1 = Bar()
    bar2 = Bar()


foo = Foo()
print(foo.bar1.parent_class_attr_name)
print(foo.bar2.parent_class_attr_name)

# >>> 'bar1'
# >>> 'bar2'