python中__get__ vs __getattr__ vs __getattribute__以及属性的搜索策略

标签：descriptor   类   python   继承   

1. 如果重载了__getattribute__,则调用.
2. a.__dict__, 实例中是不允许有descriptor的,所以不会遇到descriptor
3. A.__dict__, 也即a.__class__.__dict__ .如果遇到了descriptor,优先调用descriptor.
4. 沿着继承链搜索父类.搜索a.__class__.__bases__中的所有__dict__. 如果有多重继承且是菱形继承的情况,按MRO(Method Resolution Order)顺序搜索.

下面给个代码片段大家自己去把玩探索.

class C(object):
    def __setattr__(self, name, value):
        print "__setattr__ called:", name, value
        object.__setattr__(self, name, value)

    def __getattr__(self, name):
        print "__getattr__ called:", name

    def __getattribute__(self, name):
        print "__getattribute__ called:",name
        return object.__getattribute__(self, name)

c = C()
c.x = "foo"
print c.__dict__['x']
print c.x

python中__get__ vs __getattr__ vs __getattribute__以及属性的搜索策略

标签：descriptor   类   python   继承   

原文地址：http://blog.csdn.net/handsomekang/article/details/39929091