Django RESTful API error “type object 'User

2019-07-09 00:47发布

问题:

I'm trying to build RESTful API's with django-rest-framework and cassandra, following step by step the official django-rest-framework tutorial at Django-rest-framework I encountered this error

Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
132. response = wrapped_callback(request,  *callback_args, **callback_kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/views/decorators/csrf.py" in wrapped_view
58.         return view_func(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/views/generic/base.py" in view
  71.             return self.dispatch(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/views.py" in   dispatch
456.             response = self.handle_exception(exc)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/views.py" in   dispatch
444.             self.initial(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/views.py" in    initial
359.         self.check_permissions(request)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/views.py" in check_permissions
304.             if not permission.has_permission(request, self):
File "/usr/local/lib/python2.7/dist-packages/rest_framework/permissions.py" in has_permission
125.         perms = self.get_required_permissions(request.method, queryset.model)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/permissions.py" in get_required_permissions
104.             'app_label': model_cls._meta.app_label,

Exception Type: AttributeError at /users/
Exception Value: type object 'User' has no attribute '_meta'

This is my code

urls.py

from django.conf.urls import  url
from rest_framework.urlpatterns import format_suffix_patterns
from tutorial import views

urlpatterns = [
    # Examples:

    url(r'^users/$', views.UsersList.as_view()),
    url(r'^users/(?P<pk>[0-9]+)/$', views.UserDetail.as_view()),
]


urlpatterns = format_suffix_patterns(urlpatterns)

models.py

import uuid
from cassandra.cqlengine import columns
from cassandra.cqlengine.models import Model
# Create your models here.

class User(Model):
    id = columns.UUID(primary_key=True, default=uuid.uuid4)
    username = columns.Text(max_length=30, required=True)
    password = columns.Text(max_length=55, required=True)
    gender = columns.UUID(default=0)
    languages = columns.List(value_type=columns.UUID)
    friends = columns.Set(value_type=columns.UUID)

serializers.py

from rest_framework import serializers
from tutorial.models import User

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

views.py

from tutorial.models import User
from tutorial.serializers import UserSerializer
from rest_framework import generics

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

class UserDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer

Thank you in advance for your support.

回答1:

As far as I know cassandra's models don't implement a meta class, which is required to work with applications like rest_framework. You will need to implement django compatible models to work with rest_framework.

As stated for one of the developers of django-cassandra-engine:

cqlengine is about to be merged into python-driver soon. After that we can think about it, but it is important to know, that django-cassandra-engine never meant to be fully compatible with django models.

Github issue here



回答2:

Refer this project https://github.com/jbatalle/django-cassandra-engine/tree/master/testproject

It uses serializers.Serializer instead of serializers.ModelSerializer