Question

Really confused about what’s going on here. I have a class defined as follows:

class Profile(models.Model):
    user = models.OneToOneField(User)
    primary_phone = models.CharField(max_length=20)
    address = models.ForeignKey(Address)

    @property
    def primary_email(self): return self.user.email
    @primary_email.setter
    def primary_email(self, val): self.user.email = val

NB: user has an attribute email.

Now from the commandline, I’m trying this:

>>> u = User.objects.get(pk=1)
>>> u.email = 'xxx'
>>> u.profile.primary_email
u'yyy'

It spits out a different value? Specifically, the old value of u.email. What’s going on? How is this possible? I basically just want to create an alias for email.

---

Some more info:

>>> id(u) == id(u.profile.user)
False
>>> u
<User: mark>
>>> u.profile.user
<User: mark>

They seem to be different copies of user, but they… what? Both start with the same values?

Doing this seems to commit the changes:

>>> u.profile.primary_email = 'yyy'
>>> u.profile.user.save()

But u.save() won’t do the trick because u != u.profile.user for whatever reason. I guess that answers my question, but it’s still kind of lame.

It is possible for those two to refer to the same object in Python, right? It was just a funny design decision in Django that’s causing this?

Answer 1

Python properties per se do not work in django models because django’s models do some magic to set instance attributes. Maybe this is having an effect.