core.py 文件源码

def get_cardinality_for_field(field):
        """
        Returns the cardinality for ``field``.
        """
        cardinalities = {
            models.ForeignKey: ZeroOrOne,
            models.ManyToOneRel: ZeroOrMore,
            models.OneToOneField: ZeroOrOne,
            models.OneToOneRel: ZeroOrOne,
            models.ManyToManyField: ZeroOrMore,
            models.ManyToManyRel: ZeroOrMore,
            GenericForeignKey: ZeroOrOne,
            GenericRelation: ZeroOrMore
        }
        return cardinalities[field.__class__]