title: Django TypeError - object is not iterable
body: <p>I'm trying to get started with Django and am getting the following TypeError when attempting to access a url I defined:
  'object is not iterable'</p>
  
  <p>Here's by code:</p>
  
  <p>models.py</p>
  
  <pre><code>from django.db import models
  from django.contrib.auth.models import User
  from pubs.models import Pub
  
  # Create your models here.
  class Event (models.Model):
      name = models.CharField(max_length=200)
      description = models.CharField(max_length=500)    
      admin = models.ForeignKey(User)
      def __str__(self):
          return self.name
  
  class Event_Instance (models.Model):
      Event = models.ForeignKey(Event)
      location = models.ForeignKey(Location)
      additional_description = models.CharField(max_length=200)
      display_desc = models.BooleanField(default='true')
      time = models.DateTimeField('Event Date &amp; Time')
      def __str__(self):
          return self.Event.name
  </code></pre>
  
  <p>urls.py</p>
  
  <pre><code>from django.conf.urls import patterns, url
  from events import views
  
  urlpatterns = patterns('',
                         url(r'^(?P&lt;event_id&gt;\d+)/instance/(?P&lt;event_instance_id&gt;\d+)/$',views.event_detail, name='event_detail'),
                         )
  </code></pre>
  
  <p>views.py</p>
  
  <pre><code>from django.shortcuts import render
  from events.models import Event, Event_Instance
  from django.http import HttpResponse, Http404
  
  
  # Create your views here.
  def event_detail (request, event_id, event_instance_id):
      try:
          event_instance = Event_Instance.objects.get(pk = event_instance_id)
      except Event_Instance.DoesNotExist:
          raise Http404
      return render(request, 'events/event_instance.html', event_instance)
  </code></pre>
  
  <p>When I run the <code>Event_Instance.objects.get(pk = 1)</code> it brings up what I want, so it must be something to do with the argument I'm passing in, or the fact that I'm passing more than one argument in?</p>
  
  <p>Am I missing something really simple?</p>
  
  <p>Thanks</p>