python - Django - TypeError at/statements/int() 参数必须是字符串、类似字节的对象或数字，而不是 'AnonymousUser'

Question

在我的 Django 项目中，我有一个 statement 应用程序，它只存储注册用户的语句。我正在尝试用它来学习 Django，在某个时候，我问自己如何只显示当前用户的语句。因此，我根据当前用户过滤了查询集，然后当我想查看语句时收到此错误消息(参见标题)。

我的观点.py:

from statements.models import Statement
from statements.serializers import StatementSerializer, UserSerializer
from rest_framework import generics
from django.contrib.auth.models import User
from rest_framework import permissions
from statements.permissions import IsOwnerOrReadOnly
from rest_framework.response import Response

from rest_framework.decorators import api_view
from rest_framework.response import Response
from rest_framework.reverse import reverse

from rest_framework.views import APIView
from rest_framework.authtoken.models import Token
from rest_framework.authentication import TokenAuthentication



@api_view(['GET'])
def api_root(request, format=None):
    return Response({'links':{
        'users': reverse('user-list', request=request, format=format),
        'statements': reverse('statement-list', request=request, format=format)
    }})


class StatementList(generics.ListCreateAPIView):
    #queryset = Statement.objects.all()      <--- with this, everything was fine but I wanted to get only the statements of the current user
    serializer_class = StatementSerializer
    authentication_classes = (TokenAuthentication,)
    permission_classes = (permissions.IsAuthenticatedOrReadOnly,)

    # I've overridden this method so that only the statements of the current user should be displayed (BUT this caused the error) 
    def get_queryset(self):
        user = self.request.user
        return Statement.objects.filter(owner=user)


    def perform_create(self, serializer):
        serializer.save(owner=self.request.user)

    def list(self, request, *args, **kwargs):
        queryset = self.filter_queryset(self.get_queryset())

        page = self.paginate_queryset(queryset)

        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)

        serializer = self.get_serializer(queryset, many=True)
        return Response({'statements': serializer.data})

class StatementDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = Statement.objects.all()
    serializer_class = StatementSerializer
    permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                          IsOwnerOrReadOnly,)


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

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

我的模型.py:

from django.db import models

# Create your models here.

class Statement(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    text = models.CharField(max_length=100, blank=False)
    owner = models.ForeignKey('auth.User', related_name='statements', on_delete=models.CASCADE)

    class Meta:
        ordering = ('created',)

我的序列化器.py:

class StatementSerializer(serializers.HyperlinkedModelSerializer):
    owner = serializers.ReadOnlyField(source='owner.username')

    class Meta:
        model = Statement
        fields = ('url','id', 'text', 'owner')


class UserSerializer(serializers.HyperlinkedModelSerializer):
    statements = serializers.HyperlinkedRelatedField(many=True, view_name='statement-detail', read_only=True)

    class Meta:
        model = User
        fields = ('url', 'id', 'username', 'statements')

所以，我还阅读了有关此类型错误的其他 stackoverflow 帖子，但它们没有帮助。

Answer 1

问题出在 StatementList View 中。如果请求未经身份验证，则 request.user 的默认值是 django.contrib.auth.models.AnonymousUser 的实例。

因此，您可以在执行 Statement.objects.filter(owner=user) 查询之前检查用户是否已通过身份验证。

# views.py
class StatementList(generics.ListCreateAPIView):
    #queryset = Statement.objects.all()      <--- with this, everything was fine but I wanted to get only the statements of the current user
    serializer_class = StatementSerializer
    authentication_classes = (TokenAuthentication,)
    permission_classes = (permissions.IsAuthenticatedOrReadOnly,)

    # I've overridden this method so that only the statements of the current user should be displayed (BUT this caused the error) 
    def get_queryset(self):
        user = self.request.user
        # check if the user is authenticated
        if user.is_authenticated():
            return Statement.objects.filter(owner=user)
        return Statement.objects.none()

# END

或者您可以将 permission_classes 更改为 permissions.IsAuthenticated，它将确保只有经过身份验证的用户才能访问端点。