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Groups > comp.lang.python > #49287

Re: class factory question

References <138ce5a8-1b4c-49d4-8005-d5f4642dcb97@googlegroups.com>
Date 2013-06-27 00:35 +0100
Subject Re: class factory question
From Fábio Santos <fabiosantosart@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.3909.1372290126.3114.python-list@python.org> (permalink)

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On 26 Jun 2013 14:14, "Tim" <jtim.arnold@gmail.com> wrote:
>
> I am extending a parser and need to create many classes that are all
subclassed from the same object (defined in an external library).  When my
module is loaded I need all the classes to be created with a particular
name but the behavior is all the same. Currently I have a bunch of lines
like this:
>
>     class Vspace(Base.Command): pass
>     class Boldpath(Base.Command): pass
>
> There are a bunch of lines like that.
> Is there a better way? Something like
>
>     newclasses = ['Vspace', 'Boldpath', ... ]
>     for name in newclasses:
>         tmp = type(name, (Base.Command,) {})
>         tmp.__name__ = name
>
> Is there a more pythonic way?
> thanks,
> --Tim
>

I would say The Most Pythonic Way is to use the class declarations as you
are doing now. Explicit is better than implicit, or so the zen says.

It will be better for tools as well. I'd like to see code completion work
on dynamically created classes like that (unless you use __all__ to list
them.).

And, are you really looking for classes here? If you just want to create
different names with different identities, you could consider using plain
old strings or object() to do that.

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Thread

class factory question Tim <jtim.arnold@gmail.com> - 2013-06-26 06:09 -0700
  Re: class factory question Peter Otten <__peter__@web.de> - 2013-06-26 15:39 +0200
    Re: class factory question Tim <jtim.arnold@gmail.com> - 2013-06-26 07:08 -0700
      Re: class factory question Peter Otten <__peter__@web.de> - 2013-06-26 16:46 +0200
        Re: class factory question Tim <jtim.arnold@gmail.com> - 2013-06-26 08:05 -0700
      Re: class factory question Joshua Landau <joshua.landau.ws@gmail.com> - 2013-06-26 16:17 +0100
      Re: class factory question Peter Otten <__peter__@web.de> - 2013-06-26 17:40 +0200
      Re: class factory question Joshua Landau <joshua.landau.ws@gmail.com> - 2013-06-27 00:20 +0100
  Re: class factory question Fábio Santos <fabiosantosart@gmail.com> - 2013-06-27 00:35 +0100
  Re: class factory question Joshua Landau <joshua.landau.ws@gmail.com> - 2013-06-27 14:16 +0100
    Re: class factory question Tim <jtim.arnold@gmail.com> - 2013-06-27 06:37 -0700
      Re: class factory question Dave Angel <davea@davea.name> - 2013-06-27 09:48 -0400
        Re: class factory question Irmen de Jong <irmen.NOSPAM@xs4all.nl> - 2013-06-27 17:56 +0200
          Re: class factory question Tim <jtim.arnold@gmail.com> - 2013-06-27 09:40 -0700

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