list.py 文件源码

def get(self, request, *args, **kwargs):
        self.object_list = self.get_queryset()
        allow_empty = self.get_allow_empty()

        if not allow_empty:
            # When pagination is enabled and object_list is a queryset,
            # it's better to do a cheap query than to load the unpaginated
            # queryset in memory.
            if (self.get_paginate_by(self.object_list) is not None
                    and hasattr(self.object_list, 'exists')):
                is_empty = not self.object_list.exists()
            else:
                is_empty = len(self.object_list) == 0
            if is_empty:
                raise Http404(_("Empty list and '%(class_name)s.allow_empty' is False.")
                        % {'class_name': self.__class__.__name__})
        context = self.get_context_data()
        return self.render_to_response(context)