dates.py 文件源码

def get_dated_queryset(self, **lookup):
        """
        Get a queryset properly filtered according to `allow_future` and any
        extra lookup kwargs.
        """
        qs = self.get_queryset().filter(**lookup)
        date_field = self.get_date_field()
        allow_future = self.get_allow_future()
        allow_empty = self.get_allow_empty()
        paginate_by = self.get_paginate_by(qs)

        if not allow_future:
            now = timezone.now() if self.uses_datetime_field else timezone_today()
            qs = qs.filter(**{'%s__lte' % date_field: now})

        if not allow_empty:
            # When pagination is enabled, it's better to do a cheap query
            # than to load the unpaginated queryset in memory.
            is_empty = len(qs) == 0 if paginate_by is None else not qs.exists()
            if is_empty:
                raise Http404(_("No %(verbose_name_plural)s available") % {
                    'verbose_name_plural': force_text(qs.model._meta.verbose_name_plural)
                })

        return qs