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RE: What should Python apps do when asked to show help?

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Yup.. another reason to use something like argparse... you define the argument descriptions, help, and when you raise an error, it automatically handles the output, sending it to the right place (stderr/stdout)... as well as allowing you to define different levels of verbosity easily... (or not if you don't want)

Argparse isn't the best tool in the world, and there are some things that annoy me about it sometimes, but it works pretty well within its boundaries.

(and if the code's already written, I'm not suggesting that it be re-written just to move it to a common library.

> -----Original Message-----
> From: Python-list [mailto:python-list-bounces+d.strohl=f5.com@python.org]
> On Behalf Of Random832
> Sent: Thursday, April 28, 2016 10:30 AM
> To: python-list@python.org
> Subject: Re: What should Python apps do when asked to show help?
> 
> On Thu, Apr 28, 2016, at 13:06, Chris Angelico wrote:
> > On Fri, Apr 29, 2016 at 2:33 AM, Steven D'Aprano <steve@pearwood.info>
> > wrote:
> > > Many command line tools simply output help to stdout (or stderr, if
> > > they're evil),
> >
> > I'm not sure stderr is particularly more evil than stdout, but
> > whatever
> > :)
> 
> When a tool has very long help and sends it to stderr:
> 
> $ foo --help
> ok, it's scrolled off the top, and I could just scroll up, but it's so long I'll have to
> search for what I want anyway.
> $ foo --help | less
> *help flashes on the screen, then blank ~~~~~~ screen from less*
> #@!@#$#$!#$!@#$@#!$@!#$!@#$!@#$!@#$!@#$
> $ foo --help 2>&1 | less
> 
> Basically the only reason this ever happens is that programmers get lazy and
> use the same function for usage errors as for --help. A usage error message
> *should* go to stderr (in order to show up if the program's output has been
> redirected to null, and so as not to be silently piped to something that
> expects the program's normal output), but it should be short. Help should go
> to stdout because the user actually requested it.
> 
> The obvious exception, and probably the bad example that people are
> following, is programs that don't actually *have* --help, but briefly
> summarize all their options and the meanings of positional arguments in the
> usage error. People start with that, and then expand it to a full-blown GNU-
> style --help message, but continue sending it to stderr.
> --
> https://mail.python.org/mailman/listinfo/python-list

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What should Python apps do when asked to show help? Steven D'Aprano <steve@pearwood.info> - 2016-04-29 02:33 +1000
  Re: What should Python apps do when asked to show help? alister <alister.ware@ntlworld.com> - 2016-04-28 16:45 +0000
    RE: What should Python apps do when asked to show help? Dan Strohl <D.Strohl@F5.com> - 2016-04-28 17:02 +0000
    Re: What should Python apps do when asked to show help? John Wong <gokoproject@gmail.com> - 2016-04-28 13:05 -0400
    RE: What should Python apps do when asked to show help? Dan Strohl <D.Strohl@F5.com> - 2016-04-28 17:25 +0000
    Re: What should Python apps do when asked to show help? Ethan Furman <ethan@stoneleaf.us> - 2016-04-28 10:27 -0700
  Re: What should Python apps do when asked to show help? Ethan Furman <ethan@stoneleaf.us> - 2016-04-28 09:49 -0700
  Re: What should Python apps do when asked to show help? Chris Angelico <rosuav@gmail.com> - 2016-04-29 03:06 +1000
  Re: What should Python apps do when asked to show help? Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2016-04-28 19:08 +0200
    Re: What should Python apps do when asked to show help? Marko Rauhamaa <marko@pacujo.net> - 2016-04-28 20:31 +0300
      Re: What should Python apps do when asked to show help? Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-04-29 18:04 +1200
    RE: What should Python apps do when asked to show help? Dan Strohl <D.Strohl@F5.com> - 2016-04-28 17:32 +0000
  Re: What should Python apps do when asked to show help? Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-04-28 20:30 +0300
  Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-28 13:30 -0400
  Re: What should Python apps do when asked to show help? Grant Edwards <grant.b.edwards@gmail.com> - 2016-04-28 17:33 +0000
  RE: What should Python apps do when asked to show help? Dan Strohl <D.Strohl@F5.com> - 2016-04-28 17:39 +0000
  Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-28 13:40 -0400
  Re: What should Python apps do when asked to show help? Grant Edwards <grant.b.edwards@gmail.com> - 2016-04-28 18:14 +0000
    Re: What should Python apps do when asked to show help? Marko Rauhamaa <marko@pacujo.net> - 2016-04-28 21:31 +0300
      Re: What should Python apps do when asked to show help? Grant Edwards <grant.b.edwards@gmail.com> - 2016-04-28 19:39 +0000
      Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-28 15:51 -0400
      Re: What should Python apps do when asked to show help? Grant Edwards <grant.b.edwards@gmail.com> - 2016-04-28 21:08 +0000
        Re: What should Python apps do when asked to show help? Steven D'Aprano <steve@pearwood.info> - 2016-04-29 11:40 +1000
          manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] "Martin A. Brown" <martin@linux-ip.net> - 2016-04-29 06:32 -0700
          Re: manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] Ethan Furman <ethan@stoneleaf.us> - 2016-04-29 07:06 -0700
            Re: manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] Rustom Mody <rustompmody@gmail.com> - 2016-04-29 08:17 -0700
          Re: manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] Ben Finney <ben+python@benfinney.id.au> - 2016-04-30 12:25 +1000
            Re: manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] Rustom Mody <rustompmody@gmail.com> - 2016-04-29 20:20 -0700
              Re: manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] Paul Rubin <no.email@nospam.invalid> - 2016-04-29 21:06 -0700
                Re: manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] Rustom Mody <rustompmody@gmail.com> - 2016-04-29 23:37 -0700
                Re: manpage writing [rst, asciidoc, pod] was [Re: What should Python apps do when asked to show help?] Paul Rubin <no.email@nospam.invalid> - 2016-04-30 00:44 -0700
          Writing manual pages using Python code (was: manpage writing) Ben Finney <ben+python@benfinney.id.au> - 2016-04-30 12:25 +1000
          Re: What should Python apps do when asked to show help? cs@zip.com.au - 2016-05-01 10:06 +1000
  Re: What should Python apps do when asked to show help? Paul Rubin <no.email@nospam.invalid> - 2016-04-28 19:15 -0700
    Re: What should Python apps do when asked to show help? Rustom Mody <rustompmody@gmail.com> - 2016-04-28 22:00 -0700
      Re: What should Python apps do when asked to show help? Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-04-29 09:02 +0300
      Re: What should Python apps do when asked to show help? Steven D'Aprano <steve@pearwood.info> - 2016-04-29 19:36 +1000
        Re: What should Python apps do when asked to show help? Rustom Mody <rustompmody@gmail.com> - 2016-04-29 02:53 -0700
          Re: What should Python apps do when asked to show help? Steven D'Aprano <steve@pearwood.info> - 2016-04-30 11:20 +1000
            Re: What should Python apps do when asked to show help? Ethan Furman <ethan@stoneleaf.us> - 2016-04-29 19:09 -0700
            Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-29 22:16 -0400
              Re: What should Python apps do when asked to show help? Rustom Mody <rustompmody@gmail.com> - 2016-04-29 19:27 -0700
                Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-29 22:36 -0400
                Re: What should Python apps do when asked to show help? Rustom Mody <rustompmody@gmail.com> - 2016-04-29 19:46 -0700
                Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-29 23:14 -0400
                Re: What should Python apps do when asked to show help? Ben Finney <ben+python@benfinney.id.au> - 2016-04-30 12:49 +1000
                Re: What should Python apps do when asked to show help? Steven D'Aprano <steve@pearwood.info> - 2016-04-30 13:23 +1000
                Re: What should Python apps do when asked to show help? Ben Finney <ben+python@benfinney.id.au> - 2016-04-30 14:06 +1000
                Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-30 00:16 -0400
                Re: What should Python apps do when asked to show help? Rustom Mody <rustompmody@gmail.com> - 2016-04-29 21:34 -0700
                Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-30 01:20 -0400
                Re: What should Python apps do when asked to show help? cs@zip.com.au - 2016-05-01 09:51 +1000
                Re: What should Python apps do when asked to show help? Steven D'Aprano <steve@pearwood.info> - 2016-05-01 14:28 +1000
                Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-30 20:41 -0400
                Re: What should Python apps do when asked to show help? Grant Edwards <grant.b.edwards@gmail.com> - 2016-05-01 02:30 +0000
                Re: What should Python apps do when asked to show help? Random832 <random832@fastmail.com> - 2016-04-30 23:46 -0400

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