Re: Set a flag on the function or a global?

From	Peter Otten <__peter__@web.de>
Subject	Re: Set a flag on the function or a global?
Date	2015-06-16 15:59 +0200
Organization	None
References	<557f6676$0$21718$c3e8da3@news.astraweb.com>
Newsgroups	comp.lang.python
Message-ID	<mailman.513.1434463188.13271.python-list@python.org> (permalink)

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Steven D'Aprano wrote:

> I have a function in a module which is intended to be used by importing
> that name alone, then used interactively:
> 
>     from module import edir
>     edir(args)
> 
> 
> edir is an enhanced version of dir, and one of the enhancements is that
> you can filter out dunder methods. I have reason to believe that people
> are split on their opinion on whether dunder methods should be shown by
> default or not: some people want to see them, others do not. Since edir
> is meant to be used interactively, I want to give people a setting to
> control whether they get dunders by default or not.
> 
> I have two ideas for this, a module-level global, or a flag set on the
> function object itself. Remember that the usual way of using this will be
> "from module import edir", there are two obvious ways to set the global:
> 
> import module
> module.dunders = False
> 
> # -or-
> 
> edir.__globals__['dunders'] = False
> 
> 
> Alternatively, I can use a flag set on the function object itself:
> 
> edir.dunders = False
> 
> 
> Naturally you can always override the default by explicitly specifying a
> keyword argument edir(obj, dunders=flag).
> 
> Thoughts and feedback? Please vote: a module global, or a flag on the
> object? Please give reasons, and remember that the function is intended
> for interactive use.

"""
In general I'm wary of routines that take flags (such as 'swapped')
that really mean "use a different version of the function" -- these
flags are almost always passed from constants and so it would be more
efficient to have a second name for the variant function.
"""
http://legacy.python.org/search/hypermail/python-1994q2/0852.html

Thread

Set a flag on the function or a global? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-15 23:57 +0000
  Re: Set a flag on the function or a global? Chris Angelico <rosuav@gmail.com> - 2015-06-16 10:07 +1000
  Re: Set a flag on the function or a global? Ethan Furman <ethan@stoneleaf.us> - 2015-06-15 17:19 -0700
  Re: Set a flag on the function or a global? Ben Finney <ben+python@benfinney.id.au> - 2015-06-16 10:20 +1000
    Re: Set a flag on the function or a global? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-16 19:07 +1000
  Re: Set a flag on the function or a global? Ethan Furman <ethan@stoneleaf.us> - 2015-06-15 17:21 -0700
  Re: Set a flag on the function or a global? sohcahtoa82@gmail.com - 2015-06-15 17:24 -0700
    Re: Set a flag on the function or a global? MRAB <python@mrabarnett.plus.com> - 2015-06-16 01:35 +0100
      Re: Set a flag on the function or a global? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-16 18:18 +1000
        Re: Set a flag on the function or a global? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2015-06-16 13:45 +0100
          Re: Set a flag on the function or a global? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-16 22:46 +0000
        Re: Set a flag on the function or a global? Cameron Simpson <cs@zip.com.au> - 2015-06-17 09:51 +1000
          Re: Set a flag on the function or a global? Steven D'Aprano <steve@pearwood.info> - 2015-06-18 00:59 +1000
            Re: Set a flag on the function or a global? Laura Creighton <lac@openend.se> - 2015-06-17 17:06 +0200
              Re: Set a flag on the function or a global? Steven D'Aprano <steve@pearwood.info> - 2015-06-18 01:55 +1000
                Documenting a function signature (was: Set a flag on the function or a global?) Ben Finney <ben+python@benfinney.id.au> - 2015-06-18 10:04 +1000
                Re: Documenting a function signature (was: Set a flag on the function or a global?) Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-17 18:10 -0600
                Re: Documenting a function signature (was: Set a flag on the function or a global?) Chris Angelico <rosuav@gmail.com> - 2015-06-18 10:14 +1000
                Re: Documenting a function signature (was: Set a flag on the function or a global?) random832@fastmail.us - 2015-06-18 08:37 -0400
                Re: Documenting a function signature (was: Set a flag on the function or a global?) Laura Creighton <lac@openend.se> - 2015-06-18 23:38 +0200
                Re: Documenting a function signature Ben Finney <ben+python@benfinney.id.au> - 2015-06-19 10:41 +1000
  Re: Set a flag on the function or a global? Ron Adam <ron3200@gmail.com> - 2015-06-15 20:24 -0400
    Re: Set a flag on the function or a global? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-16 19:15 +1000
      Re: Set a flag on the function or a global? Ron Adam <ron3200@gmail.com> - 2015-06-16 07:02 -0400
  Re: Set a flag on the function or a global? Chris Angelico <rosuav@gmail.com> - 2015-06-16 10:32 +1000
  Re: Set a flag on the function or a global? Paul Rubin <no.email@nospam.invalid> - 2015-06-15 17:37 -0700
    Re: Set a flag on the function or a global? Ethan Furman <ethan@stoneleaf.us> - 2015-06-15 17:53 -0700
      Re: Set a flag on the function or a global? Paul Rubin <no.email@nospam.invalid> - 2015-06-15 19:04 -0700
    Re: Set a flag on the function or a global? MRAB <python@mrabarnett.plus.com> - 2015-06-16 02:15 +0100
    Re: Set a flag on the function or a global? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-16 18:30 +1000
  Re: Set a flag on the function or a global? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-16 07:06 +0100
    Re: Set a flag on the function or a global? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-16 19:28 +1000
  Re: Set a flag on the function or a global? Jonas Wielicki <jonas@wielicki.name> - 2015-06-16 12:00 +0200
  Re: Set a flag on the function or a global? Michael Torrie <torriem@gmail.com> - 2015-06-16 07:44 -0600
  Re: Set a flag on the function or a global? Michael Torrie <torriem@gmail.com> - 2015-06-16 07:56 -0600
  Re: Set a flag on the function or a global? Peter Otten <__peter__@web.de> - 2015-06-16 15:59 +0200
  Re: Set a flag on the function or a global? Ethan Furman <ethan@stoneleaf.us> - 2015-06-16 07:57 -0700

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