Django REST Framework:AttributeError:“DeferredAttribute”对象没有属性“isoformat”

Question

这是我第一次使用Django REST框架，我面临注册api的问题，在第一次尝试时api工作正常，但在接下来的尝试中它开始抛出此错误

AttributeError: 'DeferredAttribute' object has no attribute 'isoformat'

首先，这是我的代码： serializers.py：

class UserSerializer(serializers.ModelSerializer):

    def create(self, validated_data):
        user = User.objects.create(**validated_data)
        user.set_password(validated_data['password'])
        user.save()
        # return dict(status=True, code=1)
        return User

    class Meta:
        model = User
        fields = ['phone', 'email', 'first_name', 'last_name', 'birth_date', 'gender', 'user_type', 'password',
                  'username']
        extra_kwargs = {
            "password": {"write_only": True}
        }

api.py：

class RegisterApi(CreateAPIView):
    model = get_user_model()
    permission_classes = [permissions.AllowAny]
    serializer_class = UserSerializer

models.py：

class User(AbstractUser):

    notification_token = models.CharField(max_length=255, unique=True, blank=True, null=True)
    phone = models.CharField(
        _("Phone Number"),
        max_length=50,
        validators=[phone_validator],
        unique=True,
    )
    is_active = models.BooleanField(
        _('active'),
        default=False,
        help_text=_(
            'Designates whether this user should be treated as active. '
            'Unselect this instead of deleting accounts.'
        ),
    )
    photo = models.ImageField(
        _('Profile Picture'),
        upload_to='profile/',
        help_text=_(
            "the user's profile picture."
        ),
        blank=True,
        null=True
    )
    address = models.CharField(_("Address"), max_length=255)
    lives_in = models.ForeignKey('City', on_delete=do_nothing, null=True, blank=True)
    user_type = models.CharField(
        _("Type"),
        max_length=3,
        choices=USER_TYPES,
        help_text=_("The user's type can be one of the available choices, "
                    "refer to the Model class for the detailed list."),
    )
    birth_date = models.DateField(_('Birth Date'), blank=True, null=True)
    gender = models.CharField(choices=GENDERS, max_length=1, default='M')

    USERNAME_FIELD = "username"

    REQUIRED_FIELDS = ["first_name", "last_name", 'user_type', 'phone', 'email']

    @property
    def get_age(self) -> int:
        today = date.today()
        dob = self.birth_date
        before_dob = (today.month, today.day) < (dob.month, dob.day)
        return today.year - self.birth_date.year - before_dob

    @property
    def confirmed_phone(self) -> bool:
        return False

    @property
    def confirmed_email(self) -> bool:
        return False

    def __str__(self):
        return self.phone

现在当我发布

我得到这个错误：

Internal Server Error: /api/register/
Traceback (most recent call last):
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\django\core\handlers\exception.py", line 34, in inner
    response = get_response(request)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\django\core\handlers\base.py", line 115, in _get_response
   response = self.process_exception_by_middleware(e, request)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\django\core\handlers\base.py", line 113, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\django\views\decorators\csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\django\views\generic\base.py", line 71, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\views.py", line 505, in dispatch
    response = self.handle_exception(exc)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\views.py", line 465, in handle_exception
    self.raise_uncaught_exception(exc)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\views.py", line 476, in raise_uncaught_exception
    raise exc
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\views.py", line 502, in dispatch
    response = handler(request, *args, **kwargs)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\generics.py", line 190, in post
    return self.create(request, *args, **kwargs)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\mixins.py", line 20, in create
    headers = self.get_success_headers(serializer.data)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\serializers.py", line 562, in data
    ret = super().data
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\serializers.py", line 260, in data
    self._data = self.to_representation(self.instance)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\serializers.py", line 529, in to_representation
    ret[field.field_name] = field.to_representation(attribute)
  File "C:\Users\Simou\Desktop\Work\IT-GDS\Resto\web\restaurant\venv\lib\site-packages\rest_framework\fields.py", line 1327, in to_representation
    return value.isoformat()
AttributeError: 'DeferredAttribute' object has no attribute 'isoformat'

知道用户正在数据库中注册，但响应抛出此错误。 感谢您的帮助

Answer 1

您应该从create()方法而不是User类返回user实例：

class UserSerializer(serializers.ModelSerializer):

    def create(self, validated_data):
        user = User.objects.create(**validated_data)
        user.set_password(validated_data['password'])
        user.save()
        # return dict(status=True, code=1)
        return user # instead of User