title: Django cannot import models
body: <p>I have the following in <code>xsd_messages/forms.py</code></p>
  
  <pre><code>import xsd_training.models
  
  class UpdateRequestForm(forms.Form):
      lesson = forms.ModelChoiceField(
          queryset=xsd_training.models.Lesson.objects.all())
  </code></pre>
  
  <p>This gives the error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "./manage.py", line 10, in &lt;module&gt;
      execute_from_command_line(sys.argv)
    File "/home/will/env/xSACdb/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
      utility.execute()
    File "/home/will/env/xSACdb/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 354, in execute
      django.setup()
    File "/home/will/env/xSACdb/local/lib/python2.7/site-packages/django/__init__.py", line 21, in setup
      apps.populate(settings.INSTALLED_APPS)
    File "/home/will/env/xSACdb/local/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate
      app_config.import_models(all_models)
    File "/home/will/env/xSACdb/local/lib/python2.7/site-packages/django/apps/config.py", line 202, in import_models
      self.models_module = import_module(models_module_name)
    File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
      __import__(name)
    File "/home/will/local/xSACdb/xsd_members/models.py", line 6, in &lt;module&gt;
      from xsd_training.models import PerformedLesson
    File "/home/will/local/xSACdb/xsd_training/models.py", line 8, in &lt;module&gt;
      import xsd_messages.views
    File "/home/will/local/xSACdb/xsd_messages/views.py", line 15, in &lt;module&gt;
      from xsd_messages.forms import MailingComposeForm, UpdateRequestForm
    File "/home/will/local/xSACdb/xsd_messages/forms.py", line 14, in &lt;module&gt;
      class UpdateRequestForm(forms.Form):
    File "/home/will/local/xSACdb/xsd_messages/forms.py", line 26, in UpdateRequestForm
      queryset=xsd_training.models.Lesson.objects.all())
  AttributeError: 'module' object has no attribute 'models'
  </code></pre>
  
  <p>However models does exist as proven using the shell:</p>
  
  <pre><code>&gt;&gt;&gt; import xsd_training.models
  &gt;&gt;&gt; xsd_training.models.Lesson.objects.all()
  [&lt;Lesson...
  </code></pre>
  
  <p>What's going on?</p>