class - Python decorator to automatically define __init__ variables

Question

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

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

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

EDIT: I should mention that I use CPython 2.7.

Answer 1

Here is my first try at the decorator:

[EDIT second try: I added handling defaults for variables and checking for valid keywords. Thanks ivan_pozdeev ]

[EDIT 3: Added check for defaults is not None]

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

Here is a example:

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