What does "*list" mean?

[Greg Smethells]

What exactly does "*values" mean in the following code? Is this a
pointer to a PyList? Why can I not find good documentation on this any
where? I must be blind:
[color=blue][color=green][color=darkred]
>>> from struct import *
>>> format = "dl"
>>> values = [3.14, 42]
>>> foo = pack(format, *values)
>>> foo[/color][/color][/color]
'\x1f\x85\xebQ\ xb8\x1e\t@*\x00 \x00\x00'[color=blue][color=green][color=darkred]
>>> unpack(format, foo)[/color][/color][/color]
(3.140000000000 0001, 42)[color=blue][color=green][color=darkred]
>>>[/color][/color][/color]

More importantly still, how would you write the same code in C? If you
wanted to instead call struct_pack(PyO bject *tuple), what would the
tuple look like in C?

Thanks to anyone who can clear all this up for me.

Greg

[Diez B. Roggisch]

Re: What does "*list&quo t; mean?

Greg Smethells wrote:
[color=blue]
> What exactly does "*values" mean in the following code? Is this a
> pointer to a PyList? Why can I not find good documentation on this any
> where? I must be blind:[/color]

Just two days ago I had the same qustion, and I got this as answer from
Raymond Hettinger:

http://www.python.org/dev/doc/devel/ref/calls.html

Regarding your C question: I didn't do such a thing, but *list only makes
the items of list be used as distinct arguments - so its more a matter of
the function signature you're calling. I'm sure you'll find something about
variable list arguments somewhere - that means that you function looks like
this:

def foo(arg1, arg2, *args):
....

Diez

[Greg Brunet]

Re: What does "*list&quo t; mean?

"Raymond Hettinger" <vze4rx4y@veriz on.net> wrote in message
news:mfiWa.308$ W%3.168@nwrdny0 1.gnilink.net.. .[color=blue]
> Hmm, it sounds like the *args calling format
> needs to be added to the tutorial.
>
>
> Raymond Hettinger[/color]

And also added to the index of the reference manual! I remember trying
to figure it out the first time that I ran into it - it's pretty
frustrating to not be able to look up these kinds of 'special' symbols.

-- Greg