main.py

import fastapi

app = fastapi.FastAPI()

inventory = {}
@app.get("/store")
async def index(itemName: str | None = None, quantity: int | None = None):
    if ((quantity == None) and (itemName != None) and (itemName in inventory)):
        return inventory[itemName]
    elif ((quantity != None) and (itemName not in inventory)):
        inventory.update({itemName: quantity})
    return inventory

@app.get("/update")
async def modify(itemName: str, action: str):
    match action:
        case "inc":
            inventory.update({itemName: inventory[itemName]+1})
        case "dec":
            inventory.update({itemName: inventory[itemName]-1})
        case _:
            return {"Error": "Invalid action"}
    return inventory

@app.get("/rename")
async def rename(oldName: str, newName: str):
    if ((oldName in inventory) and (newName not in inventory)):
        quantity = inventory[oldName]
        inventory.pop(oldName)
        inventory.update({newName: quantity})
    elif (oldName not in inventory):
        return {"Error": "Invalid item name"}
    else:
        return {"Error": "Name already in use"}
    return inventory