Keyword Argument Injection with Python Decorators

In most of the object oriented codes we write, we need to set class variables to the given argument values and this is a very line-consuming thing. See what I mean:

class Test:
    def __init__(self, x, y, z, t):
        self.x = x
        self.y = y
        self.z = z
        self.t = t
        print x,y,z,t

To get over these redundant lines, I found a solution using decorators:

def injectArguments(inFunction):
    def outFunction(*args,**kwargs):
        _self = args[0]
        _self.__dict__.update(kwargs)
        inFunction(*args,**kwargs)
    return outFunction

class Test:
    @injectArguments
    def __init__(self, x, y, z, t):
        print self.x,self.y,self.z,self.t

    @injectArguments
    def fonksiyon(self, ad):
        print "Ad:",self.ad

t = Test(x=4, y=5, z=6, t=7)
t.fonksiyon(ad="Emre")

args dictionary contains the arguments and kwargs dictionary contains the keyword arguments. arg[0] corresponds to self argument. So what we do is we update self.__dict__ with {'x':4, 'y':5,'z':6,'t':7} where self corresponds to the Test instance. This way, bulky self.x = x, etc. codes are eliminated.

I don't know if any built-it decorator like this exists in Python libraries but it seems like I'll be using this a lot.