[Python-3000] suggestion: structured assignment

Thu May 29 06:47:59 CEST 2008

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
>> 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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