[Python-Dev] Extending tuple unpacking

[Nick Coghlan]

Fred L. Drake, Jr. wrote:
> On Sunday 09 October 2005 22:44, Greg Ewing wrote:
>  > I'm aware of the differences, but I still see a strong
>  > similarity where this particular feature is concerned.
>  > The pattern of thinking is the same: "I want to deal
>  > with the first n of these things individually, and the
>  > rest collectively."
> 
> Well stated.  I'm in complete agreement on this matter.

It also works for situations where "the first n items are mandatory, the rest 
are optional". This usage was brought up in the context of a basic line 
interpreter:

   cmd, *args = input.split()

Another usage is to have a Python function which doesn't support keywords for 
its positional arguments (to avoid namespace clashes in the keyword dict), but 
can still unpack the mandatory arguments easily:

   def func(*args, **kwds):
       arg1, arg2, *rest = args # Unpack the positional arguments

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
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