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Groups > comp.lang.python > #98449
| From | Marko Rauhamaa <marko@pacujo.net> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Question about math.pi is mutable |
| Date | 2015-11-08 14:43 +0200 |
| Organization | A noiseless patient Spider |
| Message-ID | <87io5cwtja.fsf@elektro.pacujo.net> (permalink) |
| References | (14 earlier) <n1n8mc$33l$1@dont-email.me> <87ziyowy83.fsf@elektro.pacujo.net> <n1nb0f$atn$1@dont-email.me> <87mvuowvzo.fsf@elektro.pacujo.net> <n1nfmf$qta$1@dont-email.me> |
BartC <bc@freeuk.com>:
> On 08/11/2015 11:50, Marko Rauhamaa wrote:
>> ========================================================================
>> import shutil
>>
>> class Source:
>> def __init__(self):
>> self.remaining = "hello world"
>>
>> def read(self, count):
>> if count <= 0:
>> return ""
>> chunk, self.remaining = self.remaining[:count], self.remaining[count:]
>> return chunk
>>
>> class Dest:
>> def write(self, stuff):
>> print("<{}>".format(stuff))
>>
>> shutil.copyfileobj(Source(), Dest())
>> ========================================================================
>
> OK, so here, it is necessary to resolve "copyfileobj" by seeing if
> "shutil" is something that contains a name "copyfileobj" that happens
> to be a method.
>
> Is this the lookup you're talking about, and is it done using the
> actual string "copyfileobj"? If so, does it need to be done every
> single time this line is executed? It would extraordinarily
> inefficient if that was the case.
No, what I'm talking about is that copyfileobj calls src.read() and
dst.write() without having any idea what kinds of objects src and dst
are. Thus, it will be difficult for a performance optimizer to get rid
of the dictionary lookups.
Marko
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Re: Question about math.pi is mutable Bartc <bc@freeuk.com> - 2015-11-06 12:30 +0000
Re: Question about math.pi is mutable Lorenzo Sutton <lorenzofsutton@gmail.com> - 2015-11-06 17:12 +0100
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Re: Question about math.pi is mutable Christian Gollwitzer <auriocus@gmx.de> - 2015-11-06 20:59 +0100
Re: Question about math.pi is mutable Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-06 23:19 +0100
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Re: Question about math.pi is mutable Steven D'Aprano <steve@pearwood.info> - 2015-11-07 13:00 +1100
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Re: Question about math.pi is mutable Bartc <bc@freeuk.com> - 2015-11-07 11:23 +0000
Re: Question about math.pi is mutable Ben Finney <ben+python@benfinney.id.au> - 2015-11-07 22:35 +1100
Re: Question about math.pi is mutable Bartc <bc@freeuk.com> - 2015-11-07 11:57 +0000
Re: Question about math.pi is mutable Ben Finney <ben+python@benfinney.id.au> - 2015-11-07 23:15 +1100
Re: Question about math.pi is mutable Bartc <bc@freeuk.com> - 2015-11-07 13:00 +0000
Re: Question about math.pi is mutable Laura Creighton <lac@openend.se> - 2015-11-07 15:09 +0100
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-07 16:23 +0200
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-07 16:28 +0200
Re: Question about math.pi is mutable Bartc <bc@freeuk.com> - 2015-11-07 15:01 +0000
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-07 19:46 +0200
Re: Question about math.pi is mutable Steven D'Aprano <steve@pearwood.info> - 2015-11-08 14:07 +1100
Re: Question about math.pi is mutable Random832 <random832@fastmail.com> - 2015-11-08 01:29 -0500
Re: Question about math.pi is mutable Steven D'Aprano <steve@pearwood.info> - 2015-11-08 13:59 +1100
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Re: Question about math.pi is mutable BartC <bc@freeuk.com> - 2015-11-08 11:19 +0000
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Re: Question about math.pi is mutable BartC <bc@freeuk.com> - 2015-11-08 12:39 +0000
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-08 14:43 +0200
Re: Question about math.pi is mutable BartC <bc@freeuk.com> - 2015-11-08 13:42 +0000
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-08 16:33 +0200
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Re: Question about math.pi is mutable BartC <bc@freeuk.com> - 2015-11-09 00:11 +0000
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Re: Question about math.pi is mutable Random832 <random832@fastmail.com> - 2015-11-09 10:32 -0500
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Re: Question about math.pi is mutable Ben Finney <ben+python@benfinney.id.au> - 2015-11-10 17:10 +1100
Re: Question about math.pi is mutable Steven D'Aprano <steve@pearwood.info> - 2015-11-10 22:34 +1100
Re: Question about math.pi is mutable BartC <bc@freeuk.com> - 2015-11-10 13:26 +0000
Re: Question about math.pi is mutable Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-11-11 18:38 +1100
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-11 10:30 +0200
Re: Question about math.pi is mutable Steven D'Aprano <steve@pearwood.info> - 2015-11-11 22:20 +1100
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Re: Question about math.pi is mutable Grant Edwards <invalid@invalid.invalid> - 2015-11-07 16:16 +0000
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-07 20:00 +0200
Re: Question about math.pi is mutable Grant Edwards <invalid@invalid.invalid> - 2015-11-08 03:31 +0000
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-08 09:45 +0200
Re: Question about math.pi is mutable Christian Gollwitzer <auriocus@gmx.de> - 2015-11-08 09:00 +0100
Re: Question about math.pi is mutable Paul Rubin <no.email@nospam.invalid> - 2015-11-08 00:08 -0800
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-08 11:49 +0200
Re: Question about math.pi is mutable Grant Edwards <invalid@invalid.invalid> - 2015-11-09 14:49 +0000
Re: Question about math.pi is mutable Bartc <bc@freeuk.com> - 2015-11-07 15:19 +0000
Re: Question about math.pi is mutable Steven D'Aprano <steve@pearwood.info> - 2015-11-08 14:50 +1100
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-08 11:44 +0200
Re: Question about math.pi is mutable Steven D'Aprano <steve@pearwood.info> - 2015-11-08 22:11 +1100
Re: Question about math.pi is mutable Marko Rauhamaa <marko@pacujo.net> - 2015-11-08 13:25 +0200
Re: Question about math.pi is mutable BartC <bc@freeuk.com> - 2015-11-08 11:06 +0000
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Re: Question about math.pi is mutable Ben Finney <ben+python@benfinney.id.au> - 2015-11-10 10:29 +1100
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