Python中的动态类属性? [英] Dynamic Class Attribute in Python?

问题描述

我正在尝试为一个类编写一个函数，该函数需要一堆文件并将它们作为属性添加到该类中.

I'm trying to write a function for a class that takes a bunch of files and adds them to the class as attributes.

现在我有一个类 foo 和另一个类 bar .我本质上想浏览一个字符串列表(这是简化的)，并将每个字符串添加为 foo 的属性，并且每个属性都属于 bar 类.代码>.因此， foo 具有一堆类型为 bar 的属性.现在，我已经使用python的 __ setattr __ 做到了这一点，并且效果很好.真正的问题是，我需要在 bar 内设置一个属性，并且需要对每个单独的 foo 属性进行设置.

Right now I have some class foo, and another class bar. I want to essentially go through a list of strings (this is simplified), and add each of those strings as an attribute of foo, and each of these attributes will be of class bar. So foo has a bunch of attributes of type bar. Now I've done this using python's __setattr__, and that's worked fine. The real issue is that I need to set an attribute within bar, and I need to do this for each individual foo attribute.

所以现在，我有一个for循环:

So for now, I have a for loop:

for name in list:
  self.__setattr__(name, bar(a, b, ..))
  self.name.a = 123

不幸的是，该属性被读取为名称"，而不是列表中的值.因此，我收到如下错误: foo对象没有属性名称.我需要的是某种动态访问.我知道 getattr ，但是据我所知，它返回一个值，并且我认为不适用于我的情况.你们知道在这里有用的任何东西吗?

Unfortunately, the attribute is read as "name" and not the value in the list. So I get an error like: foo object has no attribute name. What I need is some kinda of dynamic access. I know of getattr, but as far as I know, that returns a value, and I don't think is applicable in my case. Do you guys know of anything that would work here?

我也可以添加需要设置为构造函数参数的内容.我不愿意这样做的原因是，我认为它有点重载了构造函数，并使它变得混乱，特别是因为参数名称会很长.话虽如此，我可以在必要时这样做.

I can also add the things I need to set as constructor arguments too. The reason I'd prefer not to do that is I think it kind of overloads the constructor, and makes it kind of cluttered, especially since the argument names would be rather long. That being said, I can do that if necessary.

推荐答案

将bar实例保存在局部变量中:

Save the bar-instance in a local variable:

for name in list:
    bar_value = bar(a, b, ..)
    setattr(self, name, bar_value)
    bar_value.a = 123

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