Expand tuple into argument list?

[Fredrik Lundh]

Steven Work <steve at renlabs.com> wrote:
> 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?

http://www.python.org/doc/FAQ.html#4.31
"How do I call a function if I have the arguments in a tuple?"

...

in your case, something like:

    function = global()[fnname]
    result = apply(function, arguments)

should do the trick.  you can pass a dictionary with
keyword arguments as a third argument to apply. see
the built-in functions section in the library reference
for more info.

</F>