Django RESTful API 错误“类型对象‘用户’没有属性‘_meta’”答案

【问题标题】：Django RESTful API error "type object 'User' has no attribute '_meta'"Django RESTful API 错误“类型对象‘用户’没有属性‘_meta’”
【发布时间】：2015-07-07 00:38:35
【问题描述】：

我正在尝试使用 django-rest-framework 和 cassandra 构建 RESTful API，按照Django-rest-framework 的官方 django-rest-framework 教程一步一步操作，我遇到了这个错误

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'

这是我的代码

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

提前感谢您的支持。

【问题讨论】：

您将无法在视图中使用DjangoModelPermissions 或任何依赖于 Django 模型的权限类，因为您使用的模型不兼容。

标签： python django rest django-rest-framework cqlengine

【解决方案1】：

据我所知，cassandra 的模型没有实现元类，这是与 rest_framework 等应用程序一起工作所必需的。您需要实现与 django 兼容的模型才能使用 rest_framework。

正如 django-cassandra-engine 的一位开发者所说：

cqlengine 即将合并到 python-driver 中。之后我们可以考虑一下，但重要的是要知道，django-cassandra-engine 绝不意味着与 django 模型完全兼容。

Github 问题here

【讨论】：

【解决方案2】：

参考这个项目 https://github.com/jbatalle/django-cassandra-engine/tree/master/testproject

它使用 serializers.Serializer 而不是 serializers.ModelSerializer

【讨论】：