'User' object has no attribute 'username'

I have my User model (AbstractBaseUser of Django 1.5) i use email as the username to authenticate and have the following ModelResource for my API

class CartItemResource(ModelResource):
    product = fields.ForeignKey(CartItemRelatedResource, 'product', full=True)

    class Meta:
        queryset = CartItem.objects.all()
        resource_name = 'cart_item'
        excludes = ['creation_date', 'modification_date']
        allowed_methods = ['post', 'get', 'delete']
        authorization = CartAuthorization()
        authentication = SessionAuthentication()

When a GET request is made to the API, I get:

'User' object has no attribute 'username'

Edit User Model:

class User(AbstractBaseUser):
    objects = UserManager()
    name = models.CharField(max_length=100)
    email = models.EmailField(
        max_length=255,
        unique=True,
    )
    phone = models.IntegerField(max_length=10, null=True)
    is_admin = models.BooleanField(default=False, blank=True)
    is_driver = models.BooleanField(default=False, blank=True)
    lastOrderID = models.CharField(max_length=25, null=True)

    USERNAME_FIELD = 'email'
    #REQUIRED_FIELDS = ['name','phone']
    REQUIRED_FIELDS = ['name']

    def __unicode__(self):
        return self.user

    def set_phone(self, phone):
        self.phone = phone


class CartAuthorization(Authorization):

  def read_list(self, object_list, bundle): 
      return object_list.filter(cart__user = self.user(bundle), cart__id = bundle.request.GET.get('cart_id'))

I have another another POST in the same resource which works:

def add_to_cart(self, request, **kwargs):
    self.method_check(request, allowed=['post'])
    self.is_authenticated(request)

Traceback:

Traceback     (most recent call last):

  File "C:\Python27\lib\site-packages\tastypie\resources.py", line 195, in wrapper
    response = callback(request, *args, **kwargs)

  File "C:\Python27\lib\site-packages\tastypie\resources.py", line 426, in dispatch_list
    return self.dispatch('list', request, **kwargs)

  File "C:\Python27\lib\site-packages\tastypie\resources.py", line 454, in dispatch
    self.throttle_check(request)

  File "C:\Python27\lib\site-packages\tastypie\resources.py", line 551, in throttle_check
    identifier = self._meta.authentication.get_identifier(request)

  File "C:\Python27\lib\site-packages\tastypie\authentication.py", line 283, in get_identifier
    return getattr(request.user, username_field)

  File "C:\Python27\lib\site-packages\django\utils\functional.py", line 205, in inner
    return func(self._wrapped, *args)

AttributeError: 'User' object has no attribute 'username'

Solution

You are most likely when Django packages which rely on Django 1.4-like models where User object always has an username field. The issue is either in your own code or third party code, but the question does not has enough details to tell.

Use a full traceback to trace these addons
Update them if patched package is available
If there is no patch available you need to fork and patch the third party code yourself

About Django 1.5+ user model:

https://docs.djangoproject.com/en/stable/topics/auth/customizing/#auth-custom-user

You should most likely user id to identify the user, not username