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Re: object.enable() anti-pattern

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Date Thu, 9 May 2013 18:23:31 +1000
From Cameron Simpson <cs@zip.com.au>
To Gregory Ewing <greg.ewing@canterbury.ac.nz>
Subject Re: object.enable() anti-pattern
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On 09May2013 19:54, Greg Ewing <greg.ewing@canterbury.ac.nz> wrote:
| Steven D'Aprano wrote:
| >There is no sensible use-case for creating a file without opening
| >it. What would be the point?
| 
| Early unix systems often used this as a form of locking.

Not just early systems: it's a nice lightweight method of making a
lockfile even today if you expect to work over NFS, where not that
many things are synchronous. You open a file with "0" modes, so
that it is _immediately_ not writable. Other attempts to make the
lock file thus fail because of the lack of write, even over NFS.

Cheers,
-- 
Cameron Simpson <cs@zip.com.au>

You can listen to what everybody says, but the fact remains that you've got
to get out there and do the thing yourself.     - Joan Sutherland

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object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-08 08:52 +0000
  Re: object.enable() anti-pattern Christian Heimes <christian@python.org> - 2013-05-08 11:51 +0200
  Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-08 11:13 +0100
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-08 12:30 +0000
  Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-08 09:17 -0400
  Re: object.enable() anti-pattern Duncan Booth <duncan.booth@invalid.invalid> - 2013-05-08 14:27 +0000
    Re: object.enable() anti-pattern Dan Sommers <dan@tombstonezero.net> - 2013-05-09 02:38 +0000
      Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 05:37 +0000
        Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-09 15:52 +1000
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 03:12 +0000
  Re: object.enable() anti-pattern Dan Sommers <dan@tombstonezero.net> - 2013-05-09 02:42 +0000
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 05:23 +0000
      Re: object.enable() anti-pattern Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-09 02:41 -0400
      Re: object.enable() anti-pattern Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-09 19:54 +1200
        Re: object.enable() anti-pattern Cameron Simpson <cs@zip.com.au> - 2013-05-09 18:23 +1000
          Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 11:30 +0000
            Re: object.enable() anti-pattern Cameron Simpson <cs@zip.com.au> - 2013-05-10 09:36 +1000
              Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 05:00 +0000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 01:50 -0400
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 09:47 +0000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 09:22 -0400
                Re: object.enable() anti-pattern Cameron Simpson <cs@zip.com.au> - 2013-05-11 08:25 +1000
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-10 20:16 -0700
                Re: object.enable() anti-pattern Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2013-05-11 06:21 +0200
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-10 21:00 -0700
                Re: object.enable() anti-pattern Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-11 15:04 -0400
        Re: object.enable() anti-pattern Greg Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-10 10:56 +1200
      Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-09 09:07 -0400
        Re: object.enable() anti-pattern Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-05-09 14:51 +0100
        Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 18:21 +0000
          Re: object.enable() anti-pattern MRAB <python@mrabarnett.plus.com> - 2013-05-09 19:34 +0100
            Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 02:30 +0000
              Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-09 23:09 -0400
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-09 20:19 -0700
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-10 13:46 +1000
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 05:03 +0000
                Re: object.enable() anti-pattern Dan Sommers <dan@tombstonezero.net> - 2013-05-10 06:22 +0000
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-10 11:00 +0000
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-10 13:19 +0100
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 10:01 -0400
                Re: object.enable() anti-pattern Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-05-10 15:29 +0100
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 10:37 -0400
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 00:46 +1000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 10:54 -0400
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 01:09 +1000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 11:21 -0400
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 01:44 +1000
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-10 16:33 +0100
                Re: object.enable() anti-pattern Serhiy Storchaka <storchaka@gmail.com> - 2013-05-10 18:44 +0300
                Re: object.enable() anti-pattern André Malo <ndparker@gmail.com> - 2013-05-11 17:33 +0200
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-12 02:04 +1000
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-10 18:20 +0100
                Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-11 07:51 +0000
                Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-11 09:31 -0400
                Re: object.enable() anti-pattern Robert Kern <robert.kern@gmail.com> - 2013-05-11 20:55 +0100
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-12 08:39 +1000
                Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-11 03:24 +1000
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-10 19:43 -0700
                Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-12 11:48 -0500
                Re: object.enable() anti-pattern Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-12 16:23 -0400
                Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-09 20:51 -0700
              Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-10 13:08 +1000
          Re: object.enable() anti-pattern roy@panix.com (Roy Smith) - 2013-05-09 14:59 -0400
            Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-10 07:55 +1000
      Re: object.enable() anti-pattern Nobody <nobody@nowhere.com> - 2013-05-10 17:59 +0100
        Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-10 13:32 -0400
          Re: object.enable() anti-pattern Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2013-05-11 15:24 -0400
        Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-11 07:05 +0000
  Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-08 19:53 -0700
  Re: object.enable() anti-pattern Mark Janssen <dreamingforward@gmail.com> - 2013-05-08 19:56 -0700
  Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-09 06:08 -0500
    Re: object.enable() anti-pattern Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 11:51 +0000
    Re: object.enable() anti-pattern Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-10 11:43 +1200
      Re: object.enable() anti-pattern Michael Speer <knomenet@gmail.com> - 2013-05-09 20:18 -0400
        Re: object.enable() anti-pattern Roy Smith <roy@panix.com> - 2013-05-09 20:50 -0400
      Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-12 12:14 -0500
      Re: object.enable() anti-pattern Terry Jan Reedy <tjreedy@udel.edu> - 2013-05-12 16:03 -0400
      Re: object.enable() anti-pattern Greg Ewing <greg.ewing@canterbury.ac.nz> - 2013-05-13 11:18 +1200
      Re: object.enable() anti-pattern Fábio Santos <fabiosantosart@gmail.com> - 2013-05-13 07:32 +0100
      Re: object.enable() anti-pattern Chris Angelico <rosuav@gmail.com> - 2013-05-13 17:36 +1000
      Re: object.enable() anti-pattern Fábio Santos <fabiosantosart@gmail.com> - 2013-05-13 09:09 +0100
      Re: object.enable() anti-pattern Wayne Werner <wayne@waynewerner.com> - 2013-05-13 08:15 -0500

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