missing import

shop/views.py

@@ -4,6 +4,7 @@ from django.contrib.auth.mixins import LoginRequiredMixin
 from django.core.urlresolvers import reverse_lazy
 from django.db.models import Count, F
 from django.http import HttpResponseRedirect, Http404
+from django.shortcuts import get_object_or_404
 from django.views.generic import (
     View,
     TemplateView,