edan_f0/oscar/apps/basket/models.py

from oscar.core.loading import is_model_registered
from oscar.apps.basket.abstract_models import (
    AbstractBasket, AbstractLine, AbstractLineAttribute)


class InvalidBasketLineError(Exception):
    pass


if not is_model_registered('basket', 'Basket'):
    class Basket(AbstractBasket):
        pass


if not is_model_registered('basket', 'Line'):
    class Line(AbstractLine):
        pass


if not is_model_registered('basket', 'LineAttribute'):
    class LineAttribute(AbstractLineAttribute):
        pass