Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #104558

Re: Other difference with Perl: Python scripts in a pipe

From Ian Kelly <ian.g.kelly@gmail.com>
Newsgroups comp.lang.python
Subject Re: Other difference with Perl: Python scripts in a pipe
Date 2016-03-10 15:16 -0700
Message-ID <mailman.159.1457648213.15725.python-list@python.org> (permalink)
References <nbsp83$2p1$1@gioia.aioe.org> <CALwzidk+8mf-nxFHtsEH+1j8wFSLPNuBtfF64kgFoy2ztWqa1Q@mail.gmail.com> <nbsral$vpa$1@ger.gmane.org>

Show all headers | View raw


On Thu, Mar 10, 2016 at 3:09 PM, Peter Otten <__peter__@web.de> wrote:
> I suppose you need to fill the OS-level cache:
>
> $ cat somescript.py
> import sys
>
> for i in range(int(sys.argv[1])):
>     sys.stdout.write('line %d\n' % i)
> $ python somescript.py 20 | head -n5
> line 0
> line 1
> line 2
> line 3
> line 4
> $ python somescript.py 200 | head -n5
> line 0
> line 1
> line 2
> line 3
> line 4
> $ python somescript.py 2000 | head -n5
> line 0
> line 1
> line 2
> line 3
> line 4
> Traceback (most recent call last):
>   File "somescript.py", line 4, in <module>
>     sys.stdout.write('line %d\n' % i)
> IOError: [Errno 32] Broken pipe
>
> During my experiments I even got
>
> close failed in file object destructor:
> sys.excepthook is missing
> lost sys.stderr
>
> occasionally.

Interesting, both of these are probably worth bringing up as issues on
the bugs.python.org tracker. I'm not sure that the behavior should be
changed (if we get an error, we shouldn't just swallow it) but it does
seem like a significant hassle for writing command-line
text-processing tools.

Back to comp.lang.python | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Other difference with Perl: Python scripts in a pipe Fillmore <fillmore_remove@hotmail.com> - 2016-03-10 16:33 -0500
  Re: Other difference with Perl: Python scripts in a pipe Ian Kelly <ian.g.kelly@gmail.com> - 2016-03-10 14:46 -0700
    Re: Other difference with Perl: Python scripts in a pipe Fillmore <fillmore_remove@hotmail.com> - 2016-03-10 17:04 -0500
  Re: Other difference with Perl: Python scripts in a pipe Peter Otten <__peter__@web.de> - 2016-03-10 23:09 +0100
  Re: Other difference with Perl: Python scripts in a pipe Ian Kelly <ian.g.kelly@gmail.com> - 2016-03-10 15:16 -0700
    Re: Other difference with Perl: Python scripts in a pipe Fillmore <fillmore_remove@hotmail.com> - 2016-03-10 18:48 -0500
      Re: Other difference with Perl: Python scripts in a pipe INADA Naoki <songofacandy@gmail.com> - 2016-03-11 09:08 +0900
        Re: Other difference with Perl: Python scripts in a pipe Fillmore <fillmore_remove@hotmail.com> - 2016-03-10 19:26 -0500
          Re: Other difference with Perl: Python scripts in a pipe Alan Bawden <alan@csail.mit.edu> - 2016-03-11 01:45 -0500
            Re: Other difference with Perl: Python scripts in a pipe Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-11 12:15 +0200
          Re: Other difference with Perl: Python scripts in a pipe Ethan Furman <ethan@stoneleaf.us> - 2016-03-11 00:55 -0800

csiph-web