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Date: Wed, 28 Dec 2011 18:08:37 +1100
Subject: Re: Pythonification of the asterisk-based collection packing/unpacking syntax
From: Chris Angelico <rosuav@gmail.com>
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:18106

On Wed, Dec 28, 2011 at 5:25 PM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> On Wed, 28 Dec 2011 15:06:37 +1100, Chris Angelico wrote:
>
>> ... suppose you have a huge
>> set/frozenset using tuples as the keys, and one of your operations is to
>> shorten all keys by removing their first elements. Current Python
>> roughly doubles the cost of this operation, since you can't choose what
>> type the tail is made into.
>
> The First Rule of Program Optimization:
> - Don't do it.
>
> The Second Rule of Program Optimization (for experts only):
> - Don't do it yet.
>
>
> Building syntax to optimize imagined problems is rarely a good idea. The
> difference between 2 seconds processing your huge set and 4 seconds
> processing it is unlikely to be significant unless you have dozens of
> such huge sets and less than a minute to process them all.
>
> And your idea of "huge" is probably not that big... it makes me laugh
> when people ask how to optimize code "because my actual data has HUNDREDS
> of items!". Whoop-de-doo. Come back when you have a hundred million
> items, then I'll take your question seriously.
>
> (All references to "you" and "your" are generic, and not aimed at Chris
> personally. Stupid English language.)

And what you're seeing there is the _best possible_ situation I could
think of, the strongest possible justification for new syntax.
Granted, that may say more about me and my imagination than about the
problem, but the challenge is open: Come up with something that
actually needs this.

ChrisA