def _choose_cart_by_user_or_by_id(cls, cart_by_id: Cart,
cart_by_user: Cart) -> Cart:
if cart_by_id != cart_by_user:
if cart_by_id.user is not None and cart_by_id.user != cart_by_user.user:
return cart_by_user
if cart_by_user.get_courses_count != 0:
cart_by_id.delete()
return cart_by_user
else:
if cart_by_id.user is None:
cart_by_id.user = cart_by_user.user
cart_by_id.save()
cart_by_user.delete()
return cart_by_id
return cart_by_id