code: def changes(
      request, slug, template_name='wakawaka/changes.html', extra_context=None
  ):
      
      rev_a_id = request.GET.get('a', None)
      rev_b_id = request.GET.get('b', None)
  
      # Some stinky fingers manipulated the url
      if not rev_a_id or not rev_b_id:
          return HttpResponseBadRequest('Bad Request')
  
      try:
          revision_queryset = Revision.objects.all()
          wikipage_queryset = WikiPage.objects.all()
          rev_a = revision_queryset.get(pk=rev_a_id)
          rev_b = revision_queryset.get(pk=rev_b_id)
          page = wikipage_queryset.get(slug=slug)
      except ObjectDoesNotExist:
          raise Http404
  
      if rev_a.content != rev_b.content:
          d = difflib.unified_diff(
              rev_b.content.splitlines(),
              rev_a.content.splitlines(),
              'Original',
              'Current',
              lineterm='',
          )
          difftext = '\n'.join(d)
      else:
          difftext = _(u'No changes were made between this two files.')
  
      template_context = {
          'page': page,
          'diff': difftext,
          'rev_a': rev_a,
          'rev_b': rev_b,
      }
      template_context.update(extra_context or {})
      return render(request, template_name, template_context)
docs: Displays the changes between two revisions.