using an alias or property in place of a field in django -

I created a custom user class in django 1.5, which is the successor to the AbBabBaseUser. In the classroom there is a field 'email' which is unique ID, however, I am using an externally developed app which is the user class for username for get () Is hoping to use in I would not want to add additional unnecessary fields to my user class, and when I ask for that username, I would like to return the email address to this app I have tried to use a property in my user category:

  @property def Username (auto): return self.email   
 but I continue to receive the  field error ... in the keyword field 'User name 'Can not be solved   
 I think what this database has to do with lookups is another way to take advantage of it? Perhaps the method to specify the field name alias   
 
 
  find ()  invokes  QuerySet.filter () , there is no effect on  QuerySet  on creating the property, it only works when a  user  example attribute  Username user accesses .  
 You can do this by creating custom queries: django.db.models.query import from:  
  QuerySet class MyUserManager (baseUserManager): def __getattr__ (auto, attr, * Argus): Try Return Geetter (Auto______, Entry, * AGR), excluding Attribute Error: Return Gateter (auto.get_query_set (), atri, * AGR) df mill_query_set (self): Returns MySQL (self) .model ) MyQuerySet: def filter (self, * args, ** kwargs): If the 'username' kwargs in: kwargs.update ({'email': k Wargs.pop ('username')}) Return super (MyQuerySet, self). Filler (* Args, ** quarges) Class MyUser (AbbattBusUser): Email = ... objects = My User Manager () USERNAME_FIELD = 'email'