alternative to zip(*map(f, lst))?

[Huaiyu Zhu]

If f is a function that returns n-tuple, it is often useful to use

a1, a2, ..., an = zip(*map(f, lst))

But it breaks down when lst is an empty list.  Is there an alternative for
doing this in one statement without for loops?  It appears that list
comprehension wouldn't help here.  An example of what I mean:

>>> def f(x): return x, x*3
... 
>>> a, b = zip(*map(f, range(2))); print a, b
(0, 1) (0, 3)
>>> a, b = zip(*map(f, range(1))); print a, b
(0,) (0,)
>>> a, b = zip(*map(f, range(0))); print a, b
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
TypeError: zip() requires at least one sequence

Is is possible to get () () in the last case?  Thanks.  

Huaiyu