将 Django Rest Framework 与序列化程序一起使用时出现 AttributeError

我正在学习一个位于here的教程，该教程使用Django Rest Framework，但我不断收到关于字段的奇怪错误.

我models.py岁的时候有以下型号的

from django.db import models

class Task(models.Model):
    completed = models.BooleanField(default=False)
    title = models.CharField(max_length=100)
    description = models.TextField()

然后我的串行器在serializers.py

from rest_framework import serializers

from task.models import Task

class TaskSerializer(serializers.ModelSerializer):

    class Meta:
        model = Task
        fields = ('title', 'description', 'completed')

以及我的views.py美元，详情如下:

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

from task.models import Task
from api.serializers import TaskSerializer


    @api_view(['GET', 'POST'])
    def task_list(request):
        """
        List all tasks, or create a new task
        """
        if request.method == 'GET':
            tasks = Task.objects.all()
            serializer = TaskSerializer(tasks)
            return Response(serializer.data)

        elif request.method == 'POST':
            serializer = TaskSerializer(data=request.DATA)
            if serializer.is_valid():
                serializer.save()
                return Response(serializer.data, status=status.HTTP_201_CREATED)
            else:
                return Response(
                    serializer.errors, status=status.HTTP_400_BAD_REQUEST
                )

我的urls.py有这样一行代码:

url(r'^tasks/$', 'task_list', name='task_list'),

当我try 访问curl http://localhost:9000/api/tasks/时，我一直收到以下错误，并且我不确定如何处理它:

AttributeError at /api/tasks/
Got AttributeError when attempting to get a value for field `title` on serializer `TaskSerializer`.
The serializer field might be named incorrectly and not match any attribute or key on the `QuerySet` instance.
Original exception text was: 'QuerySet' object has no attribute 'title'.

我错过了什么？