The code should be this:
class AuthorList(LoginRequiredMixin, ListView):
template_name = 'authorList.html'
queryset = Author.objects.all()
def get_context_data(self, **kwargs):
context = super(AuthorList, self).get_context_data(**kwargs)
if int(self.kwargs['user_id']) != self.request.user.id:
raise PermissionDenied
return context
In context = Super(...).get_context_data, I changed it from AuthorCreate to AuthorList