如何装饰从文件导入的所有函数? [英] How can I decorate all functions imported from a file?

问题描述

我已经创建了许多分为不同文件的函数，现在我想为所有这些函数应用相同的装饰器，而无需修改文件，也无需一一应用装饰器.

I have created many functions that are divided into different files, now I would like to apply the same decorator for all of them without modifying the files and without applying the decorators one by one.

我尝试使用 这个解释 由 delnan 写，但我没有成功导入函数.

I have tried to use this explanation written by delnan, but I got no success for imported functions.

关于装饰器，它必须在每次执行类中的函数时使用函数参数和值更新一个列表，就像 我问的另一个问题.

About the decorator, it must update a list every time a function within a class is executexecuted with the function arguments and values, just like this other question I asked.

有什么建议可以帮助我解决这个问题吗?谢谢

Any suggestions to help me with this issue? Thanks

推荐答案

一点自省 (dir()) 和使用 getattr() 和 setattr().

A little bit of introspection (dir()) and dynamic look-up with getattr() and setattr().

首先，我们遍历模块中找到的所有名称，然后检查看起来像函数.之后，我们只需将旧函数重新分配给装饰过的函数即可.

First we iterate over all names found in module and check for objects that look like functions. After that we simply reassign old function with decorated one.

ma​​in.py:

import types
import functools

def decorate_all_in_module(module, decorator):
    for name in dir(module):
        obj = getattr(module, name)
        if isinstance(obj, types.FunctionType):
            setattr(module, name, decorator(obj))

def my_decorator(f):
    @functools.wraps(f)
    def wrapper(*args, **kwargs):
        print(f)
        return f(*args, **kwargs)
    return wrapper

import mymod1
decorate_all_in_module(mymod1, decorator)

mymod1.py:

def f(x):
    print(x)


def g(x, y):
    print(x + y)

输出:

<function f at 0x101e309d8>
2
<function g at 0x101e30a60>
7

如果您使用星型导入(from mymod import *)，则过程不会那么顺利.原因很简单——因为所有的名字都放在一个大包里，而且它们的来源没有区别，你需要很多额外的技巧来找到你想要修补的确切内容.但是，这就是我们使用命名空间的原因 - 因为它们是一个很棒的主意.

Process does not goes that smooth if you use star imports (from mymod import *). Reason is simple - because all names are in one huge bag and there no differentiation on where they come from, you need a lot of additional tricks to find what exactly you want to patch. But, well, that's why we use namespaces - because they are one honking great idea.

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