类别和列表(自动售货机)

Question

我创建了一些代码来模拟自动售货机，我想知道机器里有什么，但我无法做到这一点。

这是我在打印(机器)时的输出：

[<__main__.Vending_slot object at 0x7fd59f53db38>,
 <__main__.Vending_slot object at 0x7fd59f53dba8>,
 <__main__.Vending_slot object at 0x7fd59f53db00>,
 <__main__.Vending_slot object at 0x7fd59f53dbe0>]

代码：

class Vending_slot:

    def __init__(self, product, stock, price):
        self.product = product
        self.stock = stock
        self.price = price

    def dispense_item(self):
        print(f"You bought a {self.items[0]}.")
        self.items = items[1] 


machine = []
machine.append(Vending_slot("A1", ["Coke","Coke","Coke"], 1.5))
machine.append(Vending_slot("A2", ["Water","Water","Water"], 0.5))
machine.append(Vending_slot("B1", ["Twix","Twix","Twix"], 1))
machine.append(Vending_slot("B2", ["Gum","Gum","Gum"], 0.8))

print(machine)

Answer 1

在使用print时，需要实现__repr__方法才能看到Vendind_slot的属性。将此代码添加到您的类中：

def __repr__(self):
    return f"{self.product} {self.stock} {self.price}"

print(machine)的输出将为：

[A1 ['Coke', 'Coke', 'Coke'] 1.5,
 A2 ['Water', 'Water', 'Water'] 0.5,
 B1 ['Twix', 'Twix', 'Twix'] 1,
 B2 ['Gum', 'Gum', 'Gum'] 0.8]