title: Django Newbie ManyRelated Manager not Iterable Question
body: <p>I'm trying to create a product code (in the admin) by combining elements from two other fields - one of which is a ManyToManyField. I'd like to iterate through that field to find out if a specific product option has been chosen, and append a variation of it to that non-editable product code, like so:</p>
  
  <pre><code>class ShirtColorClass(models.Model):
      shirtcolor = models.CharField(_('Shirt Color'), unique=True, max_length=40)
      def __unicode__(self):
          return self.shirtcolor
  
  class ShirtClass(models.Model):
      shirtmodel = models.CharField(_('Model of Shirt'), max_length=40)
      shirtclr = models.ManyToManyField(_(ShirtColorClass, verbose_name='Shirt Color'))
      shirtcode = models.CharField(_('Code for the shirt'), max_length=80, editable=False)
      #...10 more fields...
      def __unicode__(self):
          return self.shirtmodel
      def save(self):
          for item in self.shirtclr: #these are the lines I'm not sure how to do
              if 'Blue' in self.shirtclr:
                  self.shirtcode = u'%s%s' % ('B', self.shirtmodel)
              else:
                  self.shirtcode = self.shirtmodel
              super(ShirtClass,self).save()
  </code></pre>
  
  <p>At the moment I'm getting a ManyRelatedManager not Iterable message, so I know I'm doing something wrong, but I don't know what... I apologize in advance for this being a stupid newbie question. Thank you.</p>