vendingmachine.py

import sys

class VendingMachineException(Exception): pass
class NotEnoughMoneyException(VendingMachineException): pass
class OutOfStockException(VendingMachineException): pass

class Product:
	def __init__(self, name='noname', price=1, stock=1):
		self.name = name
		self.price = price
		self.stock = stock

	def __eq__(self, other):
		return self.__dict__ == other.__dict__

class VendingMachine:
	def __init__(self):
		self.__inventory = [[]]
		self.__money = 0

	def getInventory(self):
		return self.__inventory

	def setInventory(self, inventory):
		self.__inventory = inventory

	def inputMoney(self, money):
		self.__money += money
		return self.__money

	def getItem(self, row, col):
		return self.__inventory[row - 1][col - 1]

	def getPrice(self, row, col):
		return self.getItem(row, col).price

	def getStock(self, row, col):
		return self.getItem(row, col).stock

	def inStock(self, row, col):
		return self.getStock(row, col) > 0

	def hasPaidEnough(self, row, col):
		return self.__money >= self.getPrice(row, col)

	def deliverItem(self, row, col):
		if self.getStock(row, col) < 1:
			raise OutOfStockException()
		if self.getPrice(row, col) > self.__money:
			raise NotEnoughMoneyException()

		# everything OK
		self.__money -= self.getPrice(row, col)
		self.__inventory[row - 1][col - 1].stock = self.getStock(row, col) - 1
		return self.getItem(row, col).name

	def __repr__(self):
		print(self.__inventory)

if __name__ == "__main__":
	vm = VendingMachine()
	vm.setInventory([
			[Product('cola', 1, 1), Product('fanta', 2, 2)],
			[Product('sprite', 3, 3), Product('applejuice', 4, 4)]
	])
	vm.inputMoney(4)
	result = vm.deliverItem(1, 1)
	print(result)