django receiver-DoesNotExist:WidgetList匹配查询不存在

我目前正在使用

@receiver

向新用户添加令牌，例如-

@receiver(post_save, sender=settings.AUTH_USER_MODEL)
def create_auth_token(sender, instance=None, created=False, **kwargs):
    if created:
        Token.objects.create(user=instance)

我还希望能够基于此模型创建默认WidgetList：

class WidgetList(MPTTModel):
    name = models.CharField(max_length=100)
    description = models.CharField(max_length=1024)
    owner = models.ForeignKey('MyAppUser')
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True)

    def __str__(self):
        return self.name

    class MPTTMEta:
        order_insertion_by = ['name']

我试着做另一个接收器-

@receiver(post_save, sender=settings.AUTH_USER_MODEL)
def create_root_list(sender, instance=None, created=False, **kwargs):
    if created:
        WidgetList.objects.create(user=instance)

编辑-在初始的

python manage.py migrate

上，我得到以下回溯：

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/__init__.py", line 351, in execute_from_command_line
    utility.execute()
  File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/__init__.py", line 343, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/base.py", line 394, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/base.py", line 445, in execute
    output = self.handle(*args, **options)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 226, in handle
    emit_post_migrate_signal(created_models, self.verbosity, self.interactive, connection.alias)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/sql.py", line 280, in emit_post_migrate_signal
    using=db)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 201, in send
    response = receiver(signal=self, sender=sender, **named)
  File "/opt/myproject_app/lib/python2.7/site-packages/guardian/management/__init__.py", line 39, in create_anonymous_user
    user.save()
  File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/base.py", line 734, in save
    force_update=force_update, update_fields=update_fields)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/base.py", line 771, in save_base
    update_fields=update_fields, raw=raw, using=using)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 201, in send
    response = receiver(signal=self, sender=sender, **named)
  File "/opt/myproject/core/models.py", line 18, in create_root_list
    WidgetList.objects.create(user=instance)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/manager.py", line 127, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/query.py", line 346, in create
    obj = self.model(**kwargs)
  File "/opt/myproject_app/lib/python2.7/site-packages/mptt/models.py", line 393, in __init__
    super(MPTTModel, self).__init__(*args, **kwargs)
  File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/base.py", line 480, in __init__
    raise TypeError("'%s' is an invalid keyword argument for this function" % list(kwargs)[0])
TypeError: 'user' is an invalid keyword argument for this function

---

比较您的回溯和代码，您可以发现错误发生在以下位置：

WidgetList.objects.create(user=instance)

您的模型

WidgetList

甚至没有

user

字段，所以很明显您不能这样做。可能您正在复制并粘贴导致错误的代码

您的模型中没有用户。我知道你指的是主人

由于没有数据，您将获得外键引用错误。使用fixture加载一些父数据。这将解决这个问题

---

您的错误发生在

validated\u data['parent']=WidgetList.objects.get（pk=user\u parent\u list）

上，您应该选中1。如果记录确实是由您的信号创建的。2.

user\u parent\u list

的值是您期望的值。我更新了问题，我刚刚意识到我有错误的回溯。我尝试运行了两次

python manage.py migrate

。第一个回溯现在包括在内。在这两种情况下，都没有创建用户，因此不确定为什么在迁移时失败。正在进行迁移。我将

user

更改为

owner

，这是一个明显的错误。现在在初始迁移时，我得到了

django.db.models.fields.related.RelatedObjectDoesNotExist:WidgetList没有父对象。

正确。我将其更新为

WidgetList.objects.create（owner=instance）

，现在得到一个新错误-

django.db.models.fields.related.related objectdoesnotextist:WidgetList没有父对象。

这很有意义，因为在迁移时表是空的。迁移做什么？我明白了！在我的测试中，我在我的模型中更改了

null=True，blank=True

，我恢复了，它工作了！当它允许我的时候，我会将它标记为已解决！是的，我想。如果它们可以为空，那么它就不会对此抱怨。

WidgetList.objects.create(user=instance)