7 e python 2.7. Eu quero adicionar um campo extra no registro do Django. Eu tento estender com o meu modelo como este:

class Seller(models.Model):
user            = models.ForeignKey(User, unique=True)
name            = models.CharField(max_length=25)
phone_number    = models.BigIntegerField()
email           = models.EmailField(max_length=75)

def __str__(self):
    return self.name;

e adiciono o form.py assim

    from django import forms
    from registration.forms import RegistrationForm
    from django.forms import ModelForm
    from django.contrib.auth.models import User
    from kerajinan.models import Product, Category, Seller

    class SellerForm(forms.ModelsForm):
        class Meta:
            model   = Seller
            fields  = ('name','phone_number','email')

e modifique o url.py assim:

url(r'^accounts/', 'registration.views.register',{'form_class':SellerForm,'backend': 'registration.backends.default.DefaultBackend'})

como usar esses modelos com registro no django e recebo sintaxe de erro com o meu ulr.py?

obrigado