Using celery in django for making orders and payments

im having trouble in using celery in django for making orders and payments can you guys help me with that -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to django

error

Reverse for 'cart_add' with arguments '('',)' not found. 1 pattern(s) tried: ['cart/add/(?P[0-9]+)/$'] -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-