Django REST 框架：类型对象 X 没有属性“get_extra_actions”

Question

Ubuntu LTS、Python 3.6.x、Django 2.2.1、DRF 3.9.3

我从 DRF 快速入门开始。 工作得很好。

跳转到DRF 教程，使用基于通用类的视图的第 3 步我在尝试manage.py runserver时收到此错误

File "/home/ubuntu/src/rasi/rais/instances/urls.py", line 11, in <module>
    path('api/', include(router.urls)),
  File "/home/ubuntu/.virtualenv/managed-research-prod/lib/python3.6/site-packages/rest_framework/routers.py", line 125, in
urls
    self._urls = self.get_urls()
  File "/home/ubuntu/.virtualenv/managed-research-prod/lib/python3.6/site-packages/rest_framework/routers.py", line 386, in
get_urls
    urls = super(DefaultRouter, self).get_urls()
  File "/home/ubuntu/.virtualenv/managed-research-prod/lib/python3.6/site-packages/rest_framework/routers.py", line 284, in
get_urls
    routes = self.get_routes(viewset)
  File "/home/ubuntu/.virtualenv/managed-research-prod/lib/python3.6/site-packages/rest_framework/routers.py", line 200, in
get_routes
    extra_actions = viewset.get_extra_actions()
AttributeError: type object 'InstanceList' has no attribute 'get_extra_actions'

为了实现教程中的建议，我只对我的代码库进行了最小的更改。

我做错了什么并不明显，当我阅读ListCreateAPIView指南时，关于get_extra_actions的信息并不多，而在其他地方寻找时似乎明显具有可比性的信息并不多

网址.py

from django.urls import include, path
from rest_framework import routers
from . import views

router = routers.DefaultRouter()
router.register(r'users',views.UserViewSet)
router.register(r'instances',views.InstanceList)                                                                            

urlpatterns = [ 
    path('', views.dash, name='dash'),
    path('api/', include(router.urls)),
]

模型.py

class User(AbstractUser):
    email = models.EmailField()
    dept = models.CharField(max_length=400)
    display_name = models.CharField(max_length=200)

class Instance(models.Model):
    name = models.CharField(max_length=200)
    flavour = models.CharField(choices=FLAVOUR_CHOICES, max_length=20)
    os = models.IntegerField(choices=OS_CHOICES)
    hostname = models.CharField(max_length=200)
    allocation_manager = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        blank=True,
        null=True,
        on_delete=models.SET_NULL,
        related_name='manager')
    allocation_notes = models.TextField(blank=True,null=True)
    requested_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        blank=True,
        null=True,
        on_delete=models.SET_NULL,
        related_name='requestor')

序列化程序.py

# Serializers define the API representation.
class UserSerializer(serializers.HyperlinkedModelSerializer):                                                               
    class Meta:
        model = User
        fields = ('url', 'username', 'email', 'is_staff')

class InstanceSerializer(serializers.HyperlinkedModelSerializer):
    allocation_manager = UserSerializer()
    requested_by = UserSerializer()

    class Meta:
        model = Instance
        fields = ('name', 'flavour', 'hostname', 'allocation_manager','requested_by')

视图.py

# Serializer Views
# ViewSets define the view behavior.

class UserViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

class UserList(generics.ListCreateAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer

class InstanceList(generics.ListCreateAPIView):
    queryset = Instance.objects.all()
    serializer_class = InstanceSerializer

注意/编辑：我发现了一些问题，但解决方案很少。

Answer 1

基本上，您正在尝试向路由器注册一个非视图集（这里是InstanceList一个视图，而不是一个视图集）。 取而代之的是，您可以简单地在 url 中使用它，如下所示：

router = routers.DefaultRouter()
router.register(r'users',views.UserViewSet)                                                                         

urlpatterns = [ 
    path('', views.dash, name='dash'),
    path('api/', include(router.urls)),
    path('api/instances/', views.InstanceList.as_view(), name="instances"),
]

Answer 2

发生此错误的原因是：您在 urls.py 和 ListAPIView 或其他通用视图中使用路由器，您应该使用 viewset.ModelViewSet 而不是通用 api 视图。