GroceryStoreAPI

A simple API that emulates the backend of a grocery store. Admins have the ability to create a store, adding inventory and specials/discounts Customers checkout by scanning items creating a shopping cart with a specific ID. Specials/discounts are automatically applied Details such as the pre-tax subtotal of the cart can be fetched.

Usage:

git clone https://github.com/plloppii/GroceryStoreAPI.git
cd GroceryStoreAPI
# Print out usage
python3 main.py
# Run all tests
python3 main.py alltests

Run main.py for all tests. Edit and comment out blocks of main.py to view test cases one by one.

API Usage:

from models import Store
# Store creation
myStore = Store(storeFile="./testStore.json")
# Customer Cart creation
firstCustomerCart = myStore.createCustomerCart()
firstCustomerCart.processItems(cartFile="./myCart.json")
firstCustomerCart.getSubtotal()

Requirements

python>=3.0

Design Requirements

Admin Inventory Creation

Creation of items in Store Support Per Unit Item Support Per lb Item Support removing scanned item. keep total correct after removal

Support Specials

Markdown, Discount on per-unit cost
Buy N for $5 Limit on Specials
- ex. buy 2 get 1 free, limit 6. prevent getting a third free item
Buy N get M of equal or lesser value for %X off,
- ex. buy 2 lbs of ground beed, get 1 lb half off

Notes

Use delaritive approach to creating the store. Checkout items are read in chronologically

Specials can be broken down into two categories:

Static Specials can be deducted into a Requirement(Buy X) and Discount(Get Y). After the requirement is met, a discount is applied. The limit being how many times the special can be used.

They are sometimes worded differently as a mean of marketing and psychological manipulation Ex. The following are all the same Specials:

Buy 1 Bags of Chips and Get 1 Free, Limit 3 ==> Scan 1 Bag: $2, Next bag scanned: $0
Buy 1 Bag of Chips and Get 1 100% off, Limit 3 ==> Scan 1 Bag: $2, Next bag Scanned: $0
Buy 2 Bags of Chips for the price of 1, Limit 3 ==> Scan 1 Bag: $2, Next bag scanned: $0

Another Ex.

Buy 3 lbs of Ground Beef and Get 2 lbs half off ==> 3lbs for $10
Buy 2 lbs of Ground Beef and Get the next 1 lb Free ==> 3lbs for $10
Buy 3 lbs of Ground Beef for $10 ==> 3lbs for $10

Dynamic Specials are more complex. After the requirement is met, the discount is applied to the next M units, until a limit is hit. Ex.

Buy 2 lbs of Ground Beef, Get next 3lbs equal or lesser value for 50% off
- Scans 4 lbs-> [2lbs * $5] + [(2lbs * $5) * 50%] = $15

JSON Object Format

Inputs of the systems are JSON format objects for portability and compatibility The Grocery Store API is broken down into down parts First, a store creation process, where a store manager can interact with a UI to create Grocery Items

Example JSON Input for Store Creation:

{
    items: [
        {
            name: "Item1",
            cost: 1.50,
            unit: "lbs",
            markdown: 0
        }
    ],
    specials: [
        {
            item: "Item1",
            buy: 3,
            discount: "$1"
        }
    ]
}

Example JSON Input of Scanned Checkout:

{
    "scannedItems": [
        {
            "item": "ground bEEf",
            "qt": 6,
            "action": "ADD"
        },
        {
            "item": "yogURT",
            "qt": 1,
            "action": "ADD"
        }
    ]
}

Specials JSON Object Format:

{
    "item": "Item1" [str, required],
    "buy": 2 [int, required],
    "cost": 6 [int, required],
    "limit": 100 [int, optional]
},
{
    "item": "Item2" [str, required],
    "buy": 3 [int, required],
    "get": 2 [int, required],
    "percent_discount": 50 [0<int<100, required]
},
{
    "item": "Granola" [str, required],
    "buy": 3 [int, required],
    "get_eq_or_lt": 2 [int, required],
    "percent_discount": 50 [int, required],
    "limit": 10 [int, optional]
}