如何将装饰器添加到现有的对象方法？ [英] How can I add a decorator to an existing object method?

问题描述

如果我使用无法控制的模块/类，该如何装饰其中一种方法？

If I'm using a module/class I have no control over, how would I decorate one of the methods?

我知道我可以： my_decorate_method（target_method）（）但我希望无论在何处发生这种情况<无需执行搜索/替换即可调用code> target_method 。

I understand I can: my_decorate_method(target_method)() but I'm looking to have this happen wherever target_method is called without having to do a search/replace.

是否有可能？

推荐答案

是可以的，但是有几个问题。
首先，您会以明显的方式从类中获取方法，而不是函数本身。

Yes it's possible, but there are several problems. First whet you get method from class in obvious way you get a warper object but not the function itself.

class X(object):
    def m(self,x):
        print x

print X.m           #>>> <unbound method X.m>
print vars(X)['m']  #>>> <function m at 0x9e17e64>

def increase_decorator(function):
    return lambda self,x: function(self,x+1)

第二个，我不知道设置新方法是否始终有效：

Second I don't know if settings new method will always work:

x = X()
x.m(1)         #>>> 1
X.m = increase_decorator( vars(X)['m'] )
x.m(1)         #>>> 2

这篇关于如何将装饰器添加到现有的对象方法？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！