filters.py 文件源码

def choices(self):
        yield {
            'selected': self.lookup_exact_val is '',
            'query_string': self.query_string({}, [self.lookup_exact_name]),
            'display': _('All')
        }
        for lookup, title in self.field.flatchoices:
            yield {
                'selected': smart_unicode(lookup) == self.lookup_exact_val,
                'query_string': self.query_string({self.lookup_exact_name: lookup}),
                'display': title,
            }