Develop a program working as a soda vending machine. The program should show the product menu with price and take user input for product number, quantity and pay amount. The output should show the total sale price including tax and the change. Organize the program with 4 functions and call them in main() based on the requirements.

Explanation:

The following vending machine program is written in Python. It creates various functions to checkItems, check cash, check stock, calculate refund etc. It calls all the necessary functions inside the main() function. The output can be seen in the attached picture below.

class Item:

   def __init__(self, name, price, stock):

       self.name = name

       self.price = price

       self.stock = stock

   def updateStock(self, stock):

       self.stock = stock

   def buyFromStock(self):

       if self.stock == 0:

           # raise not item exception

           pass

       self.stock -= 1

class VendingMachine:

   def __init__(self):

       self.amount = 0

       self.items = []

   def addItem(self, item):

       self.items.append(item)

   def showItems(self):

       print('Items in Vending Machine \n----------------')

       for item in self.items:

           if item.stock == 0:

               self.items.remove(item)

       for item in self.items:

           print(item.name, item.price)

       print('----------------\n')

   def addCash(self, money):

       self.amount = self.amount + money

   def buyItem(self, item):

       if self.amount < item.price:

           print('You can\'t but this item. Insert more coins.')

       else:

           self.amount -= item.price

           item.buyFromStock()

           print('You chose ' +item.name)

           print('Cash remaining: ' + str(self.amount))

   def containsItem(self, wanted):

       ret = False

       for item in self.items:

           if item.name == wanted:

               ret = True

               break

       return ret

   def getItem(self, wanted):

       ret = None

       for item in self.items:

           if item.name == wanted:

               ret = item

               break

       return ret

   def insertAmountForItem(self, item):

       price = item.price

       while self.amount < price:

               self.amount = self.amount + float(input('insert ' + str(price - self.amount) + ': '))

   def calcRefund(self):

       if self.amount > 0:

           print(self.amount + " refunded.")

           self.amount = 0

       print('Thank you!\n')

def main():

   machine = VendingMachine()

   item1 = Item('Kit Kat',  1.5,  2)

   item2 = Item('Potato Chips', 1.75,  1)

   item3 = Item('Snickers',  2.0,  3)

   item4 = Item('Gum',  0.50, 1)

   item5 = Item('Doritos',0.75,  3)

   machine.addItem(item1)

   machine.addItem(item2)

   machine.addItem(item3)

   machine.addItem(item4)

   machine.addItem(item5)

   print('Welcome!\n----------------')

   continueBuying = True

   while continueBuying == True:

       machine.showItems()

       selected = input('select item: ')

       if machine.containsItem(selected):

           item = machine.getItem(selected)

           machine.insertAmountForItem(item)

           machine.buyItem(item)

           a = input('buy something else? (y/n): ')

           if a == 'n':

               continueBuying = False

               machine.calcRefund()

           else:

               continue

       else:

           print('Item not available. Select another item.')

           continue

if __name__ == "__main__":

   main()