Expand tuple into argument list?

[Steven Work]

I'm new to Python.  I want a dispatch function -- takes a function
name and other arguments, calls the named function with the remaining
arguments.  This works for limited length argument lists:

def dispatch(fnname, *rest):
    fn = dispatch.func_globals[fnname]
    if len(rest)==0:
	return fn()
    elif len(rest)==1:
	return fn(rest[0])
    elif len(rest)==2:
	return fn(rest[0], rest[1])
    elif len(rest)==3:
	return fn(rest[0], rest[1], rest[2])
    elif len(rest)==4:
	return fn(rest[0], rest[1], rest[2], rest[3])

but is there a general way to expand the tuple into an argument list?
(I know about keyword arguments already.)

Lest you ask why: I'm embedding a Python interpreter in a C program; I 
need to call Python functions directly from C, and I'd like a single
point of contact to minimize the required housekeeping.
-- 
Steven Work
Renaissance Labs
steve at renlabs.com
360 647-1833