ROLE_CHOICES = (('admin','Admin'),('default','Default'), ('user', 'User'), ('pi', 'PI'))
role = models.CharField(choices=ROLE_CHOICES, unique=True, max_length=30)
+ krole_id = models.CharField(max_length=80, verbose_name="Keystone role id", null=True, blank=True)
def __unicode__(self): return u'%s' % (self.role)