Python装饰器自动定义__init__变量 [英] Python decorator to automatically define __init__ variables

问题描述

我已经厌烦了在我的 __ init __ 函数中重复输入相同的，重复的命令。我想知道我是否可以写一个装饰师为我做的工作。以下是我的问题示例：

I've got fed up of continually typing the same, repetitive commands over and over again in my __init__ function. I was wondering if I could write a decorator to do the work for me. Here's an example of my question:

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y

我可以自动将传递给函数的所有参数都变成具有相同名称的实例变量？例如：

Is there some way in which I can automatically have all arguments passed into the function become instance variables with the same names? For example:

class Point:
    @instance_variables
    def __init__(self, x, y):
        pass

其中 @instance_variables 将自动设置 self.x = x 和 self.y = y 。我怎么能这样做？

谢谢！

Where @instance_variables would automatically set self.x = x and self.y = y. How could I do this?
Thanks!

编辑：我应该提到我使用CPython 2.7。

I should mention that I use CPython 2.7.

推荐答案

这是我第一次尝试装饰：

Here is my first try at the decorator:

def instanceVariables(func):
    def returnFunc(*args, **kwargs):
        selfVar = args[0]

        argSpec = inspect.getargspec(func)
        argumentNames = argSpec[0][1:]
        defaults = argSpec[3]
        if defaults is not None:
            defaultArgDict = dict(zip(reversed(argumentNames), reversed(defaults)))
            selfVar.__dict__.update(defaultArgDict)

        argDict = dict(zip(argumentNames, args[1:]))
        selfVar.__dict__.update(argDict)


        validKeywords = set(kwargs) & set(argumentNames)
        kwargDict = {k: kwargs[k] for k in validKeywords}
        selfVar.__dict__.update(kwargDict)

        func(*args, **kwargs)

    return returnFunc

这里是一个例子：

class Test():

    @instanceVariables
    def __init__(self, x, y=100, z=200):
        pass

    def printStr(self):
        print(self.x, self.y, self.z)

a = Test(1, z=2)

a.printStr()

>>> 1 100 2

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