cache.py 文件源码

def get_ids_to_read(self, *fields):
        """ Return list of ids, that have no at least one of specified
            fields in cache

            For example::

                cache.get_ids_to_read('name', 'country_id', 'parent_id')

            This code will traverse all record ids managed by this cache,
            and find those that have no at least one field in cache.
            This is highly useful in prefetching
        """
        return [key for key, val in six.viewitems(self)
                if any(((field not in val) for field in fields))]