How to Build an Anti-Corruption Layer in Python

class LegacyOrderSystem:
    """Legacy system with awkward, unstructured data."""
    def get_order(self):
        return {
            "order_id": "ORD-123",
            "cust": "Acme Corp",
            "items": [{"sku": "A1", "qty": 2, "price_each": 10.0}],
            "ship_to": "123 Main St, Springfield"
        }


class OrderDataTransferObject:
    """Modern clean DTO used by the new system."""
    def __init__(self, order_id, customer, items, shipping_address):
        self.order_id = order_id
        self.customer = customer
        self.items = items
        self.shipping_address = shipping_address

    def __repr__(self):
        return (f"OrderDTO(id={self.order_id!r}, customer={self.customer!r}, "
                f"items={self.items!r}, address={self.shipping_address!r})")


class AntiCorruptionLayer:
    """Translates legacy format into modern DTO."""

    def __init__(self, legacy_system):
        self.legacy = legacy_system

    def get_modern_order(self):
        raw = self.legacy.get_order()
        return OrderDataTransferObject(
            order_id=raw["order_id"].replace("ORD-", ""),  # strip prefix
            customer=raw["cust"].upper(),  # normalize casing
            items=[(item["sku"], item["qty"], item["price_each"])
                   for item in raw["items"]],
            shipping_address=raw["ship_to"]
        )


if __name__ == "__main__":
    legacy = LegacyOrderSystem()
    translator = AntiCorruptionLayer(legacy)
    dto = translator.get_modern_order()
    print(dto)