[Python-ideas] the optional "as" statement inside "if" statements

[Matt Joiner]

There's no point doing this in Python since scoping is function-level
and not lexical. Just move the assignment to the line preceding the if
statement.

On Sun, Jul 1, 2012 at 8:48 AM, Mike Meyer <mwm at mired.org> wrote:
> On Sun, 1 Jul 2012 01:06:39 +1000
> Nick Coghlan <ncoghlan at gmail.com> wrote:
>> This proposal has been considered and rejected many times. It's not
>> general enough - it *only* works for those cases where the value to be
>> retained *and* the interesting condition are the same.
>>
>> Consider the simple case of a value that may be either None (not
>> interesting) or a number (interesting). Since the interesting values
>> include "0", which evaluates as False along with None, this limited
>> form of embedded assignment syntax would not help.
>
> What Nick failed to point out is that the existing uses of "as" all
> bind *specific classes of objects*, not general ones.
>
>> Embedded assignment in C isn't that limited., but nobody has yet
>> volunteered to take the radical step of proposing "(X as Y)" as a
>> general embedded assignment syntax. I suggest anyone consider such an
>> idea do a *lot* of research in the python-ideas archives first, though
>> (as the idea has seen plenty of discussion). It is not as obviously
>> flawed as the if-and-while statement only variant, but it would still
>> involve being rather persuasive to make such a significant change to
>> the language.
>
> Hasn't the BDFL rejected a general embedded assignment in any case?
>
> As a final note, reading checking the archives for your ideas will
> also give you an idea of what kinds of things are and aren't accepted
> (i.e. - what's "Pythonic") as well as process - including the kinds of
> questions you'll be asked here - that an idea goes through before
> being accepted.
>
>       <mike
> --
> Mike Meyer <mwm at mired.org>              http://www.mired.org/
> Independent Software developer/SCM consultant, email for more information.
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