Vending Machine OOP

# Design a vending machine.

# Use case list:

# select item and get price
# accept bills/coins
# dispense items purchased and return change
# refund when cancelling the request

# Possible exceptions:

# Sold out
# Not fully paid
# Not enough changes

class item:
    def __init__(self, name, price):
        self.name = str(name)
        self.price = float(price)
        print("Initializing " + self.name + " price " + str(self.price))
    def getName(self):
        return self.name
    def getPrice(self):
        return self.price

class coke(item):
    def __init__(self):
        super().__init__("Coke", 1.50)

class chips(item):
    def __init__(self):
        super().__init__("Chips", 2.00)

class twix(item):
    def __init__(self):
        super().__init__("Twix", 1.00)


class coin:
    i = 0 # imlplement later

class inventory:
    def __init__(self):
        self.inv = {} # initialize an empty dictionary of items

    def addItem(self, item, amt):
        self.inv[item.getName()] += amt
        return True

    def deductItem(self, item, amt):
        self.inv[item.getName()] -= amt
        return True

    def load(self, item, amt):
        self.inv[item.getName()] = amt
        return True

    def invLevels(self):
        print("Inventory level is: " + str(self.inv))
        return self.inv

    def checkInv(self, item):
        print("There are " + str(self.inv[item.getName()]) + " units of " + item.getName() + " left")
        return self.inv[item.getName()]

class vendingMachine:

    def __init__(self):
        print("Machine created")
        self.inv = inventory()

    def interface(self):
        while True:
            print("Welcome to the vending machine " + str(self) + "\n**************************\nWhat would you like to do?")
            print("e for exit")
            entry =  input()
            if entry == 'e':
                break

    def loadItems(self, all_items): # takes a dictionary of items, made up of item name and value to load, to load
        for item in all_items:
            self.inv.load(item[0], item[1]) # load the item and its quantity into the inventory function


def main():

    machine1 = vendingMachine() # using a vending machine object so we can have multiple vending machines

    coke1 = coke() # coke in the first machine, machine1
    chips1 = chips()
    twix1 = twix() # what's the best way to initialize and keep track of quantity of items(# of chips, cokes, etc) in the item class?

    print("my product is: " + coke1.getName()) # testing if the class works
    initialInv = [[coke1, 5], [chips1, 10], [twix1, 8]] #initialize the machine1 inventory with a dictionary
    print(initialInv)

    machine1.loadItems(initialInv)
    machine1.inv.invLevels()
    machine1.inv.checkInv(coke1)

if __name__ == '__main__':
    main()