example_using_setattr_in_descriptor.py

class Descriptor:
    def __get__(self, instance, *args):
        return getattr(instance, self.attribute_name, 'None')
    def __set__(self, instance, value):
        setattr(instance, self.attribute_name, value)
    def __delete__(self, instance):
        delattr(instance, self.attribute_name)
    def __set_name__(self, owner, name):
        self.attribute_name = name + "_hidden_part"

class User:
    field = Descriptor()

u = User()
print(u.field)
u.field = 1
print(u.field)
del u.field