Django m2m_changed信号，post_remove后自动调用post_add

如何解决Django m2m_changed信号，post_remove后自动调用post_add

当用户从 Tank 的 users 字段中删除时，我想从 Tank 的管理员中删除用户。 但是当我调用 instance.moderators.remove(*pk_set) 时，它被删除，然后通过 post_add 信号再次添加。

以这种方式工作users.pre_remove > users.post_remove > moderators.pre_remove > moderators.post_remove > moderators.pre_add > moderators.post_add

最后两个（pre_add、post_add）被不必要地调用

我正在使用 Django 管理页面进行这些操作。

型号：

class Tank(models.Model):
    device = models.OneToOneField(Device,on_delete=models.SET_DEFAULT,related_name="tank",default=1)
    users = models.ManyToManyField(settings.AUTH_USER_MODEL,related_name="tanks",blank=True)
        hidden_for_users = models.ManyToManyField(
    settings.AUTH_USER_MODEL,related_name="hidden_tanks",blank=True)
    admins = models.ManyToManyField(settings.AUTH_USER_MODEL,related_name="tanks_of_admin",blank=True)
    moderators = models.ManyToManyField(settings.AUTH_USER_MODEL,related_name="tanks_of_moderator",blank=True)
    name = models.CharField(max_length=40)

信号：

@receiver(pre_save,sender=Tank)
def set_attr_if_needed(instance,*args,**kwargs):
    # set ttype
    if not instance.ttype:
        obj,_ = Type.objects.get_or_create(name='overhead tank')
        instance.ttype = obj

@receiver(post_save,sender=Tank)
def create_device_offline_notification(instance,created,**kwargs):
    if created:
        Notification.query.fetch_or_create(instance,"device offline")
    
def __add_users_to_location(instance):
    """ add tank's users to location's users """
    location = instance.locations.filter(
        location_type__name='Apartment').first()
    if location:
        location.users.add(*instance.users.all())


def __copy_addition_to_users(instance,users):
    """ add moderators and admins to users list """
    instance.users.add(*users)

@receiver(m2m_changed,sender=Tank.users.through)
def on_tank_users_change(instance,action,pk_set,**_):
    if action == 'post_add':
        __add_users_to_location(instance=instance)
    elif action == 'post_remove':
        instance.moderators.remove(*pk_set)



@receiver(m2m_changed,sender=Tank.moderators.through)
def on_tank_moderators_change(instance,**_):
    if action == 'post_add':
        __copy_addition_to_users(users=pk_set,instance=instance)