Question

我收到错误：

AttributeError：类型对象'Shop'没有属性'inventory'

我的课程设置为：

class Shop(object):
    def __init__(self, name, inventory, margin, profit):
        self.name = name 
        self.inventory = inventory
        self.margin = margin
        self.profit = profit


# Initial inventory including 2 of each 6 models available
inventory = 12
# Markup of 20% on all sales
margin = .2
# Revenue minus cost after sale
for bike in bikes.values():
    profit = bike.cost * margin

我想要打印库存：

print "Mike's Bikes has {} bikes in stock.".format(Shop.inventory)

但仍然遇到同样的错误。我可以使用它：

print "Mike's Bikes has %d bikes in stock." % (inventory)

但我正在尝试切换到.format（）

Answer 1

您从未创建过该类的实例，因此Shop.__init__()方法也从未运行过。

您的类没有这样的属性;您为Shop类定义的唯一属性是__init__方法本身。

创建该类的实例，然后在该实例上查找该属性：

# Initial inventory including 2 of each 6 models available
inventory = 12
# Markup of 20% on all sales
margin = .2
# Revenue minus cost after sale
for bike in bikes.values():
    profit = bike.cost * margin

bikeshop = Shop("Mike's Bikes", inventory, margin, profit)
print "Mike's Bikes has {} bikes in stock.".format(bikeshop.inventory)

在使用Shop(....)创建实例时，Python创建了实例并在该实例上调用了__init__方法。因此，inventory属性已添加到实例中，然后您可以通过bikeshop.inventory访问它。

Python：错误= Class＆＃39; Foo＆＃39;没有＆＃39; bar＆＃39;会员？

1 个答案: