[Python-3000] suggestion: structured assignment

[paul bedaride]

this work, (a, (b[2], c)) = ('big', ('red', 'dog'))
but this not (a, (b[2], c)) += ('big' ('red', 'dog'))

paul bedaride

On Thu, May 29, 2008 at 6:52 AM, <allyourcode at gmail.com> wrote:

> Indeed. Thank you, Guido.
>
> On 5/28/08, Guido van Rossum <guido at python.org> wrote:
> > Apart from the missing comma after 'big' this is already supported.
> >
> > The time machine strikes again!
> >
> > --Guido
> >
> > On Wed, May 28, 2008 at 6:23 PM, Daniel Wong <allyourcode at gmail.com>
> wrote:
> >> Hi,
> >>
> >> Are there plans for introducing syntax like this:
> >>
> >> (a, (b[2], c)) = ('big' ('red', 'dog'))
> >>
> >> It seems quite doable, because Professor Hillfinger at UC Berkeley
> >> created pyth, a dialect of Python, which has this feature. See page 10
> >> of the spec he created for his students to implement the language:
> >>
> >> http://inst.eecs.berkeley.edu/~cs164/sp08/docs/pyth.pdf<http://inst.eecs.berkeley.edu/%7Ecs164/sp08/docs/pyth.pdf>
> >>
> >> Of course, this idea could also be applied to 'for' constructs (loops,
> >> list comprehensions, and generators) where assignments are implicit.
> >>
> >> Parallel looping (esp using zip) is a great use case for this. Here's
> >> a case that's come up more than once for me that "structured"
> >> assignments would solve really nicely:
> >>
> >> for n, (a, b) in enumerate(list_of_pairs): ...
> >>
> >> Currently, I must do the following instead:
> >>
> >> for n, pair in enumerate(list_of_pairs):
> >>  a, b = pair
> >>  ...
> >>
> >> This isn't such a great solution, because there's more indirection
> >> with the introduction of an otherwise useless variable; and (less
> >> significantly) there's an extra line of code that doesn't actually
> >> compute anything.
> >>
> >> Thoughts?
> >>
> >> Daniel
> >>
> >> PS: Sorry if this has already been discussed; I'm new to this list and
> >> I didn't see this mentioned in PEP 3099, unless it's covered under the
> >> LL(1) clause.
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> >>
> >
> >
> >
> > --
> > --Guido van Rossum (home page: http://www.python.org/~guido/<http://www.python.org/%7Eguido/>
> )
> >
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