DRF TypeError 'type' object is not iterable

Question

I'm making my first DRF api and I get a strange TypeError when I try to access to my data using a GET request, I get this error:

'type' object is not iterable

Here are some code snippets bellow.

models.py

from django.db import models

# Create your models here.

class Expediteur(models.Model):
    nom = models.CharField(max_length=50)
    prenom = models.CharField(max_length=100)
    adresse = models.CharField(max_length=200)
    tel = models.IntegerField()

views.py

from django.shortcuts import render, get_object_or_404
from rest_framework import viewsets
from rest_framework.views import APIView
from rest_framework.response import Response
from polls.serializers import ExpediteurSerializer, DestinataireSerializer, LettrePrioSerializer, TypeLettreRecoSerializer, LettreRecoSerializer, TimbrePrioSerializer, TimbreRecoSerializer
from polls.models import Expediteur, Destinataire, LettrePrio, TypeLettreReco, LettreReco, TimbrePrio, TimbreReco
from rest_framework import status, HTTP_HEADER_ENCODING

import json
import datetime

from django.http import HttpResponseRedirect, HttpResponse, Http404
from django.core.urlresolvers import reverse
from django.contrib.auth.decorators import user_passes_test
from django.contrib.auth import login
from django.core.exceptions import ObjectDoesNotExist
from django.views.decorators.csrf import csrf_exempt
from django.utils.timezone import get_current_timezone
from django.db.models.query import QuerySet

# Create your views here.

class ExpeViewSet(APIView):
    QuerySet = Expediteur.objects.all()
    serializer_class = ExpediteurSerializer

    def get(self, request):
        serializer = ExpediteurSerializer(QuerySet, many=True)
        return Response(serializer.data)

    def post(self, request):
        serializer = self.serializer_class(data=request.DATA)
        return Response(status=status.HTTP_201_CREATED)

serializers.py

from rest_framework import serializers
from polls.models import Expediteur, Destinataire, LettrePrio, TypeLettreReco, LettreReco, TimbrePrio, TimbreReco


class ExpediteurSerializer(serializers.ModelSerializer):
    class Meta:
        model = Expediteur

I also leave the Traceback for more informations:

Environment:


Request Method: GET
Request URL: http://0.0.0.0:8000/polls/expediteur/

Django Version: 1.7.1
Python Version: 2.7.6
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'rest_framework',
 'polls')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Traceback:
File "/Library/Python/2.7/site-packages/Django-1.7.1-py2.7.egg/django/core/handlers/base.py" in get_response
  111.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Library/Python/2.7/site-packages/Django-1.7.1-py2.7.egg/django/views/decorators/csrf.py" in wrapped_view
  57.         return view_func(*args, **kwargs)
File "/Library/Python/2.7/site-packages/Django-1.7.1-py2.7.egg/django/views/generic/base.py" in view
  69.             return self.dispatch(request, *args, **kwargs)
File "/Library/Python/2.7/site-packages/rest_framework/views.py" in dispatch
  452.             response = self.handle_exception(exc)
File "/Library/Python/2.7/site-packages/rest_framework/views.py" in dispatch
  449.             response = handler(request, *args, **kwargs)
File "/Users/mehdi/rendu/ProjectWeek/CUP/polls/views.py" in get
  29.         return Response(serializer.data)
File "/Library/Python/2.7/site-packages/rest_framework/serializers.py" in data
  618.         ret = super(ListSerializer, self).data
File "/Library/Python/2.7/site-packages/rest_framework/serializers.py" in data
  213.                 self._data = self.to_representation(self.instance)
File "/Library/Python/2.7/site-packages/rest_framework/serializers.py" in to_representation
  568.             self.child.to_representation(item) for item in iterable

Exception Type: TypeError at /polls/expediteur/
Exception Value: 'type' object is not iterable

Answer 1

If you want to list all expediteur instances, you should use list view not get. Remember that get is for retrieving one instance.

Also, in your imports you have from django.db.models.query import QuerySet and then when you try ExpediteurSerializer(QuerySet, many=True) you are trying to serialize QuerySet type imported previously. To get your defined QuerySet, you need to use self. But I recommend use just queryset

class ExpeViewSet(GenericAPIView):
      queryset = Expediteur.objects.all() 
      serializer_class = ExpediteurSerializer


      def list(self,request):
          queryset  = self.Expediteur.objects.all() 
          serializer = ExpediteurSerializer(self.get_queryset(), many=True)
          return Response(serializer.data)