Re: No os.copy()? Why not?

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Date	Wed, 4 Apr 2012 18:37:20 +1000
Subject	Re: No os.copy()? Why not?
From	Chris Angelico <rosuav@gmail.com>
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On Wed, Apr 4, 2012 at 3:53 PM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> On Tue, 03 Apr 2012 15:46:31 -0400, D'Arcy Cain wrote:
>
>> def cp(infile, outfile):
>>    open(outfile, "w").write(open(infile).read())
>
> Because your cp doesn't copy the FILE, it copies the file's CONTENTS,
> which are not the same thing.

And, as a subtle point: This method can't create the file "at size". I
don't know how it'll end up allocating space, but certainly there's no
opportunity to announce to the OS at file open/create time "please
allocate X bytes for this file". That may be an utterly trivial point,
or a crucially vital one.

ChrisA

Thread

No os.copy()?  Why not? John Ladasky <john_ladasky@sbcglobal.net> - 2012-03-28 13:12 -0700
  Re: No os.copy()? Why not? alex23 <wuwei23@gmail.com> - 2012-03-28 21:50 -0700
    Re: No os.copy()? Why not? John Ladasky <john_ladasky@sbcglobal.net> - 2012-03-30 02:25 -0700
  Re: No os.copy()? Why not? Ian Kelly <ian.g.kelly@gmail.com> - 2012-04-02 14:48 -0600
  Re: No os.copy()?  Why not? HoneyMonster <someone@someplace.invalid> - 2012-04-02 21:11 +0000
    Re: No os.copy()?  Why not? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2012-04-03 08:24 +0200
      Re: No os.copy()? Why not? John Ladasky <john_ladasky@sbcglobal.net> - 2012-04-03 02:34 -0700
        Re: No os.copy()? Why not? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2012-04-04 14:30 +0200
      Re: No os.copy()? Why not? Ian Kelly <ian.g.kelly@gmail.com> - 2012-04-03 10:29 -0600
  Re: No os.copy()?  Why not? D'Arcy Cain <darcy@druid.net> - 2012-04-03 15:46 -0400
    Re: No os.copy()?  Why not? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-04-04 05:53 +0000
      Re: No os.copy()? Why not? Chris Angelico <rosuav@gmail.com> - 2012-04-04 18:37 +1000
        Re: No os.copy()? Why not? Steve Howell <showell30@yahoo.com> - 2012-04-04 08:15 -0700
      Re: No os.copy()?  Why not? Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2012-04-04 11:22 +0200
        Re: No os.copy()?  Why not? Roy Smith <roy@panix.com> - 2012-04-04 08:14 -0400
          Re: No os.copy()?  Why not? Nobody <nobody@nowhere.com> - 2012-04-04 20:37 +0100
      Re: No os.copy()?  Why not? Roy Smith <roy@panix.com> - 2012-04-04 08:08 -0400
        Re: No os.copy()? Why not? Chris Angelico <rosuav@gmail.com> - 2012-04-04 22:17 +1000
  Re: No os.copy()?  Why not? Tycho Andersen <tycho@tycho.ws> - 2012-04-03 15:10 -0500
  Re: Re: No os.copy()?  Why not? Evan Driscoll <driscoll@cs.wisc.edu> - 2012-04-03 15:21 -0500

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