Django REST Framework:“BasePermissionMetaclass”对象不是iterab

Question

Python/Django n00b从javascript移过来。

尝试使用Django REST Framework添加API端点，我希望最终能够用补丁请求的主体更新用户，但目前我只希望它不会抛出500个错误。

我已将此添加到urlpatterns：

url(r'update/$', views.UpdateView.as_view(), name="update_user"),

这应该会带来这样的观点：

from django.contrib.auth.models import User
from rest_framework.generics import UpdateAPIView
from .serializers import UserSerializer

class UpdateView(UpdateAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer

用户序列化程序如下所示：

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ('username', 'pk', 'status')

似乎每次我到这条路的时候都能看到：

TypeError at /api/update/
'BasePermissionMetaclass' object is not iterable

我不知道我在做什么-以前有人看过吗？

更新：完整回溯：

Internal Server Error: /api/update/
Traceback (most recent call last):
  File "path/to/myapp/env/lib/python2.7/site-packages/django/core/handlers/exception.py", line 41, in inner
    response = get_response(request)
  File "path/to/myapp/env/lib/python2.7/site-packages/django/core/handlers/base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "path/to/myapp/env/lib/python2.7/site-packages/django/core/handlers/base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "path/to/myapp/env/lib/python2.7/site-packages/django/views/decorators/csrf.py", line 58, in wrapped_view
    return view_func(*args, **kwargs)
  File "path/to/myapp/env/lib/python2.7/site-packages/django/views/generic/base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "path/to/myapp/env/lib/python2.7/site-packages/rest_framework/views.py", line 495, in dispatch
    response = self.handle_exception(exc)
  File "path/to/myapp/env/lib/python2.7/site-packages/rest_framework/views.py", line 455, in handle_exception
    self.raise_uncaught_exception(exc)
  File "path/to/myapp/env/lib/python2.7/site-packages/rest_framework/views.py", line 483, in dispatch
    self.initial(request, *args, **kwargs)
  File "path/to/myapp/env/lib/python2.7/site-packages/rest_framework/views.py", line 401, in initial
    self.check_permissions(request)
  File "path/to/myapp/env/lib/python2.7/site-packages/rest_framework/views.py", line 333, in check_permissions
    for permission in self.get_permissions():
  File "path/to/myapp/env/lib/python2.7/site-packages/rest_framework/views.py", line 280, in get_permissions
    return [permission() for permission in self.permission_classes]
TypeError: 'BasePermissionMetaclass' object is not iterable

Answer 1

我也有同样的问题，但找错了地方。我做了一个有权限的mixin类，里面有代码

permission_classes = (
    permissions.IsAuthenticated
)

但应该是

   permission_classes = (
        permissions.IsAuthenticated,
    )

所以不要忘记寻找其他有权限的类。我希望它能帮助别人。

Answer 2

作为可能在这里搜索的其他人的参考，这也可能是一个问题。。

from django.contrib.auth.models import User
from rest_framework.generics import UpdateAPIView
from .serializers import UserSerializer

class UpdateView(UpdateAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer
    permission_classes = IsAuthenticated

应改为：

    from django.contrib.auth.models import User
    from rest_framework.generics import UpdateAPIView
    from .serializers import UserSerializer

    class UpdateView(UpdateAPIView):
        queryset = User.objects.all()
        serializer_class = UserSerializer
        permission_classes = [IsAuthenticated]

Answer 3

您在DEFAULT_PERMISSION_CLASSES值中键入了错误的逗号，因此Django将其作为字符串而不是元组。

解决方案：

REST_FRAMEWORK = {
   ...
   'DEFAULT_PERMISSION_CLASSES': ( 'rest_framework.permissions.IsAdminUser', ),
   ...
}