Python：如何引用一个实例名？ [英] Python: how to refer to an instance name?

问题描述

我正在使用以下代码收集实例：

I'm collecting instances using the following code:

class Hand():
    instances = []
    def __init__(self):
        Hand.instances.append(self)
        self.value = 5

    def do_something(self, a):
        self.value = self.value * a

class Foo():
    def __init__(self):
        pass

    def insty(self):
        self.hand1 = Hand()
        self.hand2 = Hand()


foo = Foo()
foo.insty()
print Hand.instances

for hand in Hand.instances:
    print "how do I print the instance name?"

最后一行只是一种方法来学习如何访问实例名称，

The last line is just a way to learn how to to access the instance name so i can call the 'do_something' method on each instance in order.

如何访问每个实例的实例名称？

How do I access the instance name for each instance of Hand?

推荐答案

如果你想要从你分配给 self.hand1 的实例中获取 hand1 code>，答案是你不能。当你执行 self.hand1 = Hand（）时，你告诉Foo对象它有一个Hand，但Hand对象不知道它已被分配给一个Foo。您可以这样做：

If you mean how to get hand1 from the instance you assigned to self.hand1, the answer is that you can't. When you do self.hand1 = Hand(), you tell the Foo object it has a Hand, but the Hand object has no knowledge that it has been assigned to a Foo. You could do this:

h = Hand()
self.bob = h
self.larry = h

现在手的名字是什么？你为bob和larry分配了同一只手，所以没有办法得到一个唯一的名字。

Now what is the "name" of that Hand supposed to be? You assigned the same hand to both "bob" and "larry", so there's no way it can have a single unique name.

如果你想要一个名字每一只手，你需要告诉手什么名字你想给它。你必须修改你的Hand代码，以允许你传递一个名字给构造函数，然后用 Hand（some name）创建Hand。

If you want to have a name for each hand, you need to tell the hand what name you want to give it. You would have to modify your Hand code to allow you to pass a name to the constructor, then create the Hand with Hand("some name").

您当然可以通过为其指定属性来赋予手名称：

You can of course give the hands "names" by assigning attributes on them:

self.hand1 = Hand()
self.hand1.name = "hand 1"

。 。 。但这些名称不以任何方式特殊或自动。

. . . but these names are not special or "automatic" in any way.

底线是，如果你想要某个名称， >需要决定如何处理这个名字。你需要编写自己的代码，给它它的名字，和你自己的代码，检索它的名字。

The bottom line is that if you want something to have a name, you need to decide how to handle that name. You need write your own code that gives it its name, and your own code that retrieves its name.

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