Here is another version implemented as a decorator. Actually I’d also like not to use inspect, but didn’t find any nice way to get the kwargs default values wit

Here is another version implemented as a decorator. Actually I’d also like not to use inspect, but didn’t find any nice way to get the kwargs default values without it, any suggestion? import inspect def autoinit(decorated_init): def _wrap(*args, **kwargs): obj, nargs= args[0], args[1:] names = decorated_init.func_code.co_varnames[1:len(nargs)+1] nargs = {k: nargs[names.index(k)] for k in names} kwa_keys = decorated_init.func_code.co_varnames[len(nargs)+1:] kwa_defaults = inspect.getargspec(decorated_init).defaults for k in kwa_keys: nargs[k] = kwargs[k] if (k in kwargs) else kwa_defaults[kwa_keys.index(k)] for k, v in nargs.iteritems(): setattr(obj, k, v) return decorated_init(*args, **kwargs) return _wrap if __name__ == '__main__': class Foo(): @autoinit def __init__(self, a, b, x=0, y=0): self.p = 'Hello, I am set inside the __init__' self.s = self.a + self.b + self.x + self.y f = Foo(1, 2, x=120, y=5) for param in 'abxyps': print param, '=>', getattr(f, param) f = Foo(31, 33, x=64) for param in 'abxyps': print param, '=>', getattr(f, param) f = Foo(7, 121) for param in 'abxyps': print param, '=>', getattr(f, param)