title: Django: "Object is not iterable", when trying to modify said object
body: <p>I am trying to edit an object ("Worry") which has been already created.</p>
  
  <p>I have this code in views.py:</p>
  
  <pre><code>def worry_edit(request, id):
      worry = get_object_or_404(Worry, pk = id)
      original_pub_date = worry.pub_date
      form = WorryForm(request.POST or None, instance = worry)
      if form.is_valid():
          worry = form.save(commit = False)
          worry.pub_date = original_pub_date
          worry.save()
          return redirect(worry)
      return render_to_response('holaProy/worry_edit.html', {'worry_form': form, 'worry_id': id}, context_instance=RequestContext(request))
  </code></pre>
  
  <p>Which gives the following error when hitting the send button on the form:</p>
  
  <pre><code>argument of type 'Worry' is not iterable
  </code></pre>
  
  <p>Any insights on why that error is appearing and how to solve it?</p>
  
  <p>Edit: As suggested by Girasquid, this is the complete traceback:</p>
  
  <pre><code>Environment:
  
  Request Method: POST
  Request URL: http://127.0.0.1:8000/holaProy/worry_edit/1/
  
  Django Version: 1.4.1
  Python Version: 2.7.3
  Installed Applications:
  ('django.contrib.auth',
   'django.contrib.contenttypes',
   'django.contrib.sessions',
   'django.contrib.sites',
   'django.contrib.messages',
   'django.contrib.staticfiles',
   'django.contrib.admin',
   'django.contrib.admindocs',
   'holaProy',
   'registration',
   'django.contrib.humanize')
  Installed Middleware:
  ('django.middleware.common.CommonMiddleware',
   'django.contrib.sessions.middleware.SessionMiddleware',
   'django.middleware.csrf.CsrfViewMiddleware',
   'django.contrib.auth.middleware.AuthenticationMiddleware',
   'django.contrib.messages.middleware.MessageMiddleware')
  
  
  Traceback:
  File "C:\Python27\lib\site-packages\django\core\handlers\base.py" in get_response
    111.                         response = callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\Richard\proyectosPython\holaProyecto\holaProyecto\holaProy\views.py" in worry_edit
    50.         return redirect(worry)
  File "C:\Python27\lib\site-packages\django\shortcuts\__init__.py" in redirect
    81.         if '/' not in to and '.' not in to:
  
  Exception Type: TypeError at /holaProy/worry_edit/1/
  Exception Value: argument of type 'Worry' is not iterable
  </code></pre>