python属性get和set order是什么?

本文介绍了python属性get和set order是什么?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

Python为我们提供了许多关于实例/类属性的可能性，例如:

Python provides us many possibilities on instance/class attribute, for example:

class A(object): def __init__(self): self.foo = "hello" a = A()

有许多方法可以访问/更改self.foo的值:

There are many ways to access/change the value of self.foo:

直接访问a.foo

内部字典a.__dict__['foo']

获取并设置a.__get__和a.__set__，当然有两种预定义的方法.

getattribute a.__getattribute__

__getattr__和__setattr__

也许更多.

direct access a.foo

inner dict a.__dict__['foo']

get and set a.__get__ and a.__set__,of course there two are pre-defined methods.

getattribute a.__getattribute__

__getattr__ and __setattr__

maybe more.

在阅读源代码时，我总是迷失了他们的最终访问顺序是什么?当我使用a.foo时，如何知道将实际调用哪个方法/属性?

While reading source code, I always get lost of what's their ultimate access order? When I use a.foo, how do I know which method/attribute will get called actually?

推荐答案

bar = a.foo ...

调用a.__getattribute__('foo')

默认情况下依次查找a.__dict__['foo']

如果在A上定义，

或调用foo的.__get__().

invokes a.__getattribute__('foo')

which in turn by default looks up a.__dict__['foo']

or invokes foo's .__get__() if defined on A.

然后将返回值分配给bar.

a.foo = bar ...

调用a.__getattribute__('foo')

默认情况下依次查找a.__dict__['foo']

或如果在A上定义，则调用foo的.__set__(bar).

invokes a.__getattribute__('foo')

which in turn by default looks up a.__dict__['foo']

or invokes foo's .__set__(bar) if defined on A.