将装饰器列表应用于可调用对象？ [英] Apply a list of decorators to a callable?

问题描述

给出装饰器方法列表，如何将这些方法应用于可调用方法？

Given a list of decorator methods, how would one apply those to a callable?

例如，由于：

@foo
@bar
def baz():
    pass

...是等同于：

def baz():
    pass
baz = foo(bar(baz)))

...人们会以为带有装饰器列表（ [ foo，bar] ）可以将它们动态地应用于 baz 。

...one would assume that with a list of decorators ([foo, bar]) they could be applied to baz dynamically.

推荐答案

还有另一个装饰器！

def yad(decorators):
    def decorator(f):
        for d in reversed(decorators):
            f = d(f)
        return f
    return decorator

示例用法

 list_of_decorators = [foo, bar]

@yad(list_of_decorators)
def foo():
    print 'foo'

没有装饰器语法，看起来像是

Without the decorator syntax, it would look like

 func = yad(list_of_decorators)(func)

如果您要将同一列表应用于多个功能，则可以执行以下操作：

If you wanted to apply the same list to multiple functions, you can do it like:

 dec = yad(list_of_decorators)

 func1 = dec(func1)

 @dec
 def func2():
     pass

这些注释，您可以定义 yad （我敢肯定有一个更好的名字）来接受 * decorators 装饰器。然后，如果要在原位创建列表 ，则不必使用方括号。如果列表是在其他地方创建的，那么我演示的方法会更好。

As recursive points out in the comments, you can define yad (I'm sure there's a better name for this) to accept *decorators instead of decorators. Then you don't have to use brackets if you're creating the list in situ. The way that I've demonstrated is better if the list is created elsewhere.

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