What am i missing?

from django.core.urlresolvers import reverse
from django.db import models


class Product(models.Model):
    name = models.CharField(max_length=255)
    description = models.TextField()
    price = models.DecimalField()
    discount = models.DecimalField(blank=True, null=True)



    def __str__(self):
        return self.name

    def get_absolute_url(self):
        return reverse("products:detail", kwargs={"pk": self.pk})

    class Meta:
        permissions = (
            ("can_give_discount", "give discounts"),
        )

from django.contrib.auth.mixins import LoginRequiredMixin
from django.views import generic
from django.contrib.auth import has_perm

from . import models


class List(generic.ListView):
    model = models.Product


class Detail(generic.DetailView):
    model = models.Product


class Create(LoginRequiredMixin, generic.CreateView):
    fields = ("name", "description", "discount", "price")
    model = models.Product

    def form_valid(self, form):
        user = self.request.user
        if not user.has_perm('products.can_give_discount'):
            self.object.discount = 0
        self.object.save()
        return super(form_valid, self).form_valid(form)