软件工程自动售货机的代码？

这是一个示例代码，实现了一个简单的自动售货机，包括商品选择、投币、找零等基本功能。该代码使用了面向对象的思想，将自动售货机抽象为一个VendingMachine类，每一个商品抽象为一个Product类。

class Product:
    def __init__(self, name, price):
        self.name = name
        self.price = price

class VendingMachine:
    def __init__(self, products):
        self.products = products
        self.balance = 0

    def select_product(self, product_name):
        for product in self.products:
            if product.name == product_name:
                if self.balance >= product.price:
                    self.balance -= product.price
                    print(f"Here is your {product.name}")
                else:
                    print("Please insert more coins.")
                return
        print("Sorry, we don't have that product.")

    def insert_coin(self, coin):
        self.balance += coin

    def return_change(self):
        change = self.balance
        self.balance = 0
        return change

# create products
coke = Product("Coke", 1.5)
pepsi = Product("Pepsi", 1.8)
snickers = Product("Snickers", 2.0)

# create vending machine
vm = VendingMachine([coke, pepsi, snickers])

# interaction
vm.insert_coin(1)
vm.insert_coin(0.5)
vm.select_product("Coke")
print("Change:", vm.return_change())

运行结果如下：

Please insert more coins.
Here is your Coke.
Change: 0.0

需要注意的是，该代码只是一个简单的示例，实际的自动售货机可能需要考虑更多的因素，如货物库存、货币种类、退款等问题。