Python 简单裸对象 [英] Python simple naked objects

问题描述

创建可以为其分配属性的裸对象的最简单方法是什么?

What's the easiest way to create a naked object that I can assign attributes to?

具体用例是:我在一个 Django 对象实例上做各种操作，但有时实例是 None(实例上有).在这种情况下，我想创建最简单的假对象，以便我可以为其属性分配值(例如 myobject.foo = 'bar').

The specific use case is: I'm doing various operations on a Django object instance, but sometimes the instance is None (there is on instance). In this case I'd like to create the simplest possible fake object such that I can assign values to its attributes (eg. myobject.foo = 'bar').

基本上，我正在寻找与这段 Javascript 等效的 Python:

Basically I'm looking for the Python equivalent of this piece of Javascript:

myobject = {}
myobject.foo = 'bar'

我知道我可以为此使用模拟对象/库，但我希望有一个非常简单的解决方案(就像上面的 Javascript 一样简单).有没有办法创建一个裸对象实例?类似的东西:

I know I can use a mock object/library for this, but I'm hoping for a very simple solution (as simple as the Javascript above). Is there a way to create a naked object instance? Something like:

myobject = object()
myobject.foo = 'bar'

推荐答案

你需要先创建一个简单的类:

You need to create a simple class first:

class Foo(object):
    pass

myobject = Foo()
myobject.foo = 'bar'

你可以把它做成这样的单线:

You can make it a one-liner like this:

myobject = type("Foo", (object,), {})()
myobject.foo = 'bar'

对type 的调用与之前的class 语句的功能相同.

The call to type functions identically to the previous class statement.

如果你想真正极简...

myobject = type("", (), {})()

关键是内置类型(如list和object)不支持自定义属性，所以需要使用class 语句或对 type 的 3 参数版本的调用.

The key is that the built-in types (such as list and object) don't support user-defined attributes, so you need to create a type using either a class statement or a call to the 3-parameter version of type.

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