django 다중 연관표 조작

class AssetGroup(models.Model):
    GROUP_TYPE = (
        ('P','PRIVATE'),
        ('A','ASSET')
    )
    name = models.CharField(max_length=80,unique=True)
    comment = models.CharField(max_length=300,blank=True,null=True)

    def __unicode__(self):
        return self.name

class Asset(models.Model):
    """
          
    """
    group = models.ManyToManyField(AssetGroup, blank=True, verbose_name=u"   ")
    env = models.IntegerField(choices=ASSET_ENV, blank=True, null=True, verbose_name=u"    ")
    ip = models.CharField(max_length=32, blank=True, null=True, verbose_name=u"  IP")
    other_ip = models.CharField(max_length=255, blank=True, null=True, verbose_name=u"  ip     ip")
    system_version = models.CharField(max_length=8, blank=True, null=True, verbose_name=u"     ")
    kernel_version = models.CharField(max_length=32,blank=True,null=True,verbose_name=u'      ')
    ssh_version = models.CharField(max_length=32,blank=True,null=True,verbose_name=u'ssh    ')
    status = models.IntegerField(choices=ASSET_STATUS, blank=True, null=True, default=1, verbose_name=u"    ")
    idc = models.ForeignKey(IDC, blank=True, null=True,  on_delete=models.SET_NULL, verbose_name=u'  ')
    cpu = models.CharField(max_length=64, blank=True, null=True, verbose_name=u'CPU')
    memory = models.CharField(max_length=128, blank=True, null=True, verbose_name=u'  ')
    disk = models.CharField(max_length=1024, blank=True, null=True, verbose_name=u'  ')
    date_added = models.DateTimeField(auto_now=True, null=True)
    comment = models.CharField(max_length=128, blank=True, null=True, verbose_name=u"  ")

2.    ：
            ，   2       ，            ，                
          ：

Group = AssetGroup.objects.filter(