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Groups > comp.lang.python > #39371

Re: improving performance of writing into a pipe

Newsgroups comp.lang.python
Date 2013-02-20 09:54 -0800
References (3 earlier) <kftm2l$b84$1@r03.glglgl.gl> <8f26ac4d-4732-46ac-bf4e-877696b22241@googlegroups.com> <mailman.1958.1361211131.2939.python-list@python.org> <85cd2254-0800-4448-9117-9175bbfd10f6@googlegroups.com> <mailman.2055.1361296049.2939.python-list@python.org>
Subject Re: improving performance of writing into a pipe
From mikprog@gmail.com
Message-ID <mailman.2122.1361385285.2939.python-list@python.org> (permalink)

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On Tuesday, February 19, 2013 5:47:16 PM UTC, Michael Torrie wrote:
> On 02/19/2013 02:24 AM, mikprog@gmail.com wrote:
> 
> > Or rather: what would you try to catch in this particular case?
> 
> 
> As Peter said, nothing for now.  But you seem very resistant to telling
> 
> us what exception was raised.


Michael believe me: 
I am not resistant or try to hide anything!
As written before, I don't know what exception to search for, so I wrote the (wrong) code:
except:
  print "error"
Let's why I don't have a clue about it.
But someone already explained me that I should not do this. 


 
> 
> Though looking at your code more closely I can see that likely the error
> 
> is related to the fact that /tmp/mypipe is not an executable program.

Yes it is and has rwx permissions.
Unfortunately I don't have access to the code in the pipe.



> > popen (which is deprecated and replaced by the subprocess module) is for
> 
> running programs and communicating with them over pipes created by the
> 
> popen function.  So your code is not likely to ever work as it is
> 
> presently given.
> 
> 
> 
> Here's the bash equivalent of your code:
> 
> 
> 
> $ mkfifo /tmp/path
> 
> $ cat </tmp/path &
> 
> $ echo hello, world | /tmp/path
> 
> 
> 
> Bash will say, "bash: /tmp/path: Permission denied"
> 
> 
> 
> The correct bash line is:
> 
> $ echo hello, world > /tmp/path
> 
> 
> 
> popen() (and subprocess) is the equivalent of the first bash command.
> 
> open() is the equivalent of the second line.
> 

> Do you understand the difference?


I think I do now, thanks.
mik

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Thread

improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 07:12 -0800
  Re: improving performance of writing into a pipe Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-02-18 15:21 +0000
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 08:31 -0800
      Re: improving performance of writing into a pipe Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2013-02-18 17:49 +0100
        Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 09:00 -0800
          Re: improving performance of writing into a pipe Michael Torrie <torriem@gmail.com> - 2013-02-18 11:12 -0700
            Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 01:24 -0800
              Re: improving performance of writing into a pipe Peter Otten <__peter__@web.de> - 2013-02-19 10:55 +0100
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 02:27 -0800
                Re: improving performance of writing into a pipe Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-02-19 11:15 +0000
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 02:27 -0800
              Re: improving performance of writing into a pipe Michael Torrie <torriem@gmail.com> - 2013-02-19 10:47 -0700
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-20 09:54 -0800
                Re: improving performance of writing into a pipe John Gordon <gordon@panix.com> - 2013-02-20 18:39 +0000
                Re: improving performance of writing into a pipe Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-02-20 22:05 +0000
                Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-20 09:54 -0800
            Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 01:24 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-18 08:31 -0800
  Re: improving performance of writing into a pipe Serhiy Storchaka <storchaka@gmail.com> - 2013-02-18 21:29 +0200
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 04:10 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 04:10 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 05:39 -0800
      Re: improving performance of writing into a pipe Peter Otten <__peter__@web.de> - 2013-02-19 14:57 +0100
        Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 06:38 -0800
        Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 06:38 -0800
    Re: improving performance of writing into a pipe mikprog@gmail.com - 2013-02-19 05:39 -0800

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