python - Building cascade structure -

i want build cascade structure category-subject-post in project. here code:

models.py:

class category(models.model):     category_name = models.charfield(max_length=60, unique=true)     slug_category = models.slugfield(unique=true)      def get_absolute_url(self):     return reverse("skill:subjects", kwargs={"slug_category": self.slug_category})  class subject(models.model):     category = models.foreignkey(category)     subject_name = models.charfield(max_length=100, unique=true)     slug_subject = models.slugfield(unique=true)       def get_absolute_url(self):     return reverse("skill:subject", kwargs={         "slug_category": self.category.slug_category,         "slug_subject": self.slug_subject     })   class post(models.model):     subject = models.foreignkey(subject)     ... 

views.py:

def index(request):     context = {         'category_it': category.objects.filter(class_name='it'),         'category_ps': category.objects.filter(class_name='ps'),         'category_ac': category.objects.filter(class_name='ac'),         'category_tc': category.objects.filter(class_name='tc'),         'category_sc': category.objects.filter(class_name='sc'),         'category_ss': category.objects.filter(class_name='ss'),     }     return render(request, 'skill/index.html', context)  class subjectsview(generic.listview):     model = subject     queryset = subject.objects.all()     template_name = "skill/subjects.html"   class subjectview(generic.listview):     model = post     queryset = post.objects.all()     template_name = 'skill/subject.html' 

urls.py:

url(r'^$', views.index, name='index'),     # /programming     url(r'^(?p<slug_category>[\w-]+)/$', views.subjectsview.as_view(), name='subjects'),     # /programming/git     url(r'^(?p<slug_category>[\w-]+)/(?p<slug_subject>[\w-]+)/$', views.subjectview.as_view(), name='subject'),     # /programming/git/43121     url(r'^(?p<slug_category>[\w-]+)/(?p<slug_subject>[\w-]+)/(?p<pk>[0-9]+)/$', views.post, name='post'), ] 

templates:

index.html:

{% category in category_it %}     <a href="{% url 'skill:subjects' category.slug_category %}" class="item">{{ category }}</a> {% endfor %} 

subjects.html:

{% object in object_list %}     <a href="{{ object.get_absolute_url }}" class="item"><h4>{{ object }}</h4></a> {% endfor %} 

i don't know query need , where(views or template), tried , hardcoded (index in views.py , template 6times larger) can't afford on next step because of scope.

i need categories in index.html, list of subjects belonging particular category in subjects.html , posts belonging subject in subject.html. can please me finding working solution

this site invaluable work way around class based views (listview)

i think need override get method, this:

class subjectsview(generic.listview):     ...      def get(self, request, *args, slug_category=none, **kwargs):         if slug_category:             self.queryset = subject.objects.filter(category__slug_category=slug_category)         super(subjectsview, self).get(request, *args, slug_category=slug_category, **kwargs)