Compare grocery prices by the quantity you need

I built an offline Python sample that compares grocery offers by the quantity someone actually needs. It converts grams and millilitres, rounds up to whole packs and keeps invalid prices out of the calculation.

For a two-litre milk request, a twelve-litre carton costs SAR 60 even though its price per litre is lower. Two single-litre packs cost SAR 12. The sample handles this distinction instead of ranking offers by unit price alone.

The included shopping list has three items. Of 17 fictional offers, 15 pass the checks and two are rejected. The selected item prices total SAR 55.90. The code passed 14 tests, and the portable ZIP was unpacked and run separately. The sample files and source code are available on request.

This is a personal demonstration using invented prices. It matches known catalogue items and selects one offer per item. Delivery charges, taxes, coupons, minimum orders and live stock are outside this example. It is not a live store, BuildShip or WhatsApp integration.