使用 django rest 框架教程时出现 TypeError

Question

我是使用 Django Rest 框架的新手，我正在关注本教程 Django-Rest-Framework

我的模型不是 sn-ps，而是由一个用户配置文件组成，如下所示：

class UserProfile(models.Model):
      user = models.OneToOneField(User)
      emp_code = models.CharField(max_length=10, blank=True)
      user_type = models.IntegerField(max_length=1, default=0, choices=USER_TYPE)
      group = models.ForeignKey(Group, null=True, blank=True)
      status = models.SmallIntegerField(max_length=1,default=0)
      added_on = models.DateTimeField(auto_now_add=True)

教程的第一部分运行良好，如前所述，得到了所需的 json 格式输出，但是从第二个教程开始，我收到了类型错误：

TypeError at /authentication/userprofile/
'type' object is not iterable
Request Method: GET
Request URL:    http://*****.com/authentication/userprofile/
Django Version: 1.6
Exception Type: TypeError
Exception Value:    
'type' object is not iterable
Exception Location: /home/web/cptm_venv/lib/python2.7/site-     packages/rest_framework/views.py in get_permissions, line 226
Python Executable:  /usr/bin/python
Python Version: 2.7.3
Python Path:    
['/home/web/cptm_venv/lib/python2.7/site-packages',
 '/home/web/cptm',
 '/home/web/cptm_venv/lib/python2.7/site-packages',
 '/usr/lib/python2.7',
 '/usr/lib/python2.7/plat-linux2',
 '/usr/lib/python2.7/lib-tk',
 '/usr/lib/python2.7/lib-old',
 '/usr/lib/python2.7/lib-dynload',
 '/usr/local/lib/python2.7/dist-packages',
 '/usr/lib/python2.7/dist-packages',
 '/usr/lib/pymodules/python2.7']
 Server time:   Wed, 11 Dec 2013 17:33:54 +0530
 Traceback Switch to copy-and-paste view

/home/web/cptm_venv/lib/python2.7/site-packages/django/core/handlers/base.py in get_response
                response = wrapped_callback(request, *callback_args, **callback_kwargs) ...
▶ Local vars
/home/web/cptm_venv/lib/python2.7/site-packages/django/views/generic/base.py in view
        return self.dispatch(request, *args, **kwargs) ...
▶ Local vars
/home/web/cptm_venv/lib/python2.7/site-packages/django/views/decorators/csrf.py in    wrapped_view
    return view_func(*args, **kwargs) ...
▶ Local vars
/home/web/cptm_venv/lib/python2.7/site-packages/rest_framework/views.py in dispatch
        response = self.handle_exception(exc) ...
▶ Local vars
/home/web/cptm_venv/lib/python2.7/site-packages/rest_framework/views.py in dispatch
        self.initial(request, *args, **kwargs) ...
▶ Local vars
/home/web/cptm_venv/lib/python2.7/site-packages/rest_framework/views.py in initial
    self.check_permissions(request) ...
▶ Local vars
/home/web/cptm_venv/lib/python2.7/site-packages/rest_framework/views.py in   check_permissions
     for permission in self.get_permissions(): ...
▶ Local vars
/home/web/cptm_venv/lib/python2.7/site-packages/rest_framework/views.py in get_permissions
    return [permission() for permission in self.permission_classes] ...
▶ Local vars

其余代码与上述链接中的第二部分和第三部分几乎相同： 视图.py

from apps.authentication.models import UserProfile
from apps.authentication.serializers import UserProfileSerializer
from rest_framework import mixins
from rest_framework import generics

class UserProfileList(mixins.ListModelMixin,
              mixins.CreateModelMixin,
              generics.GenericAPIView):
    queryset = UserProfile.objects.all()
    serializer_class = UserProfileSerializer

    def get(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        return self.create(request, *args, **kwargs)


class UserProfileDetail(mixins.RetrieveModelMixin,
                mixins.UpdateModelMixin,
                mixins.DestroyModelMixin,
                generics.GenericAPIView):
    queryset = UserProfile.objects.all()
    serializer_class = UserProfileSerializer

    def get(self, request, *args, **kwargs):
        return self.retrieve(request, *args, **kwargs)

    def put(self, request, *args, **kwargs):
        return self.update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return self.destroy(request, *args, **kwargs)

urls.py

from django.conf.urls import patterns, url
from rest_framework.urlpatterns import format_suffix_patterns
from apps.authentication import views

urlpatterns = patterns('',
    url(r'^userprofile/$', views.UserProfileList.as_view()),
    url(r'^userprofile/(?P<pk>[0-9]+)/$', views.UserProfileDetail.as_view()),
)

urlpatterns = format_suffix_patterns(urlpatterns)

我遗漏了一些非常明显的东西，尝试了很多来搜索“类型对象不可迭代”在这种情况下的确切含义，以及哪个对象导致了问题，但没有运气。我正在使用 Django Rest Framework 2.3 版。

提前致谢

Answer 1

为了让其他人知道，我一直收到同样的错误，发现我忘记在REST_FRAMEWORK 中包含逗号。我有这个：

'DEFAULT_PERMISSION_CLASSES': (
    'rest_framework.permissions.IsAuthenticated'
),

而不是这个：

'DEFAULT_PERMISSION_CLASSES': (
    'rest_framework.permissions.IsAuthenticated',
),

逗号将其定义为one-element tuple

Answer 2

在我的例子中，错字在views.py。而不是...

permission_classes = (permissions.IsAuthenticated,)

...我有...

permission_classes = (permissions.IsAuthenticated)

Answer 3

正如上面 Daniel 所指出的，我在设置文件中有这个愚蠢的 sn-p，这是导致问题的原因，

#REST_FRAMEWORK = {
#   '''Use hyperlinked styles by default'''
#   '''only used if serializer_class attribute is not set on a view'''
#   'DEFAULT_MODEL_SERIALIZER_CLASS':
#         'rest_framkework.serializers.HyperLinkedModelSerializer',
#   'DEFAULT_PERMISSION_CLASSES':
#          'rest_framework.permissions.DjangoModelPermissionsOrAnonReadOnly'
# }

评论了这个并且它起作用了。

Answer 4

我在使用自定义权限时遇到了同样的错误，因为“错字”

我有：

@permission_classes(EventByFacilityPermissions)
class EventByFacilityViewSet(viewsets.ModelViewSet):

代替：

@permission_classes((EventByFacilityPermissions,))
class EventByFacilityViewSet(viewsets.ModelViewSet):

Answer 5

如果您只需要在某些类中进行身份验证，则在您的类中而不是在您的 settings.py 中传递身份验证类，并这样做：

authentication_classes = [TokenAuthentication, ]

而不是这样：

authentication_classes = TokenAuthentication