Why is "unpacking" of tuples only allowed when there's 1 tupple ?

[Stef Mientki]

hello,

I'm not sure if  "unpacking" is the right term
but if I have a tuple of 2 arrays,
I can either call a function with:

          Space_State = tf2ss ( filt[0], filt[1] )

or with
          Space_State = tf2ss ( *filt )

Now if I've to call a function with more parameters,
why can't I use (Polynome is again a tuple of 2 arrays) :
(which already gives an error in the IDE)

          Respons = signal.lfilter ( *Polynome, Signal )

and thus I've to use:

          Respons = signal.lfilter ( Polynome[0], Polynome[1], Signal )


I use Python 2.5.2

thanks,
Stef Mientki