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Re: all() is slow?

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On 11/10/2011 3:51 AM, Devin Jeanpierre wrote:

>> Because Python doesn't allow "--" to be an attribute name, and so
>> namedtuple doesn't let you try:
>>
>> t = namedtuple("T", "foo -- bar")(1, 2, 3)
>> print(t.foo)
>> print(t.--)
>> print(t.bar)
>
> '--' is a valid attribute name on virtually any object that supports
> attribute setting (e.g. function objects).

ob.-- is not valid Python because '--' is not a name.

 > Of course, you need to use setattr() and getattr().

I consider the fact that CPython's setattr accepts non-name strings to 
be a bit of a bug. Or if you will, leniency for speed. (A unicode name 
check in Py3 would be much more expensive than an ascii name check in 
Py2.) I would consider it legitimate for another implementation to only 
accept names and to use a specialized name_dict for attribute dictionaries.

So I consider it quite legitimate for namedtuple to requires real names 
for the fields. The whole point is to allow ob.name access to tuple 
members. Someone who plans to use set/getattr with arbitrary strings 
should just use a dict instead of a tuple.

-- 
Terry Jan Reedy

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all() is slow? "OKB (not okblacke)" <brenNOSPAMbarn@NObrenSPAMbarn.net> - 2011-11-07 21:00 +0000
  Re: all() is slow? Chris Rebert <clp2@rebertia.com> - 2011-11-07 13:39 -0800
  Re: all() is slow? david vierra <codewarrior0@gmail.com> - 2011-11-07 13:46 -0800
    Re: all() is slow? Chris Angelico <rosuav@gmail.com> - 2011-11-08 09:06 +1100
      Re: all() is slow? Henrik Faber <hfaber@invalid.net> - 2011-11-08 13:09 +0100
        Re: all() is slow? Chris Angelico <rosuav@gmail.com> - 2011-11-08 23:14 +1100
        Re: all() is slow? John Posner <jjposner@optimum.net> - 2011-11-08 17:51 -0500
        Re: all() is slow? Tim Chase <python.list@tim.thechases.com> - 2011-11-08 17:56 -0600
    Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-08 19:44 -0500
      Re: all() is slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-09 02:47 +0000
        Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-09 18:01 -0500
          Re: all() is slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-09 23:11 +0000
            Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-09 20:26 -0500
              Re: all() is slow? alex23 <wuwei23@gmail.com> - 2011-11-09 19:50 -0800
                Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-09 23:40 -0500
                Re: all() is slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-10 07:35 +0000
              Re: all() is slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-10 07:48 +0000
                Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-10 03:51 -0500
                Re: all() is slow? gene heskett <gheskett@wdtv.com> - 2011-11-10 08:20 -0500
                Re: all() is slow? Terry Reedy <tjreedy@udel.edu> - 2011-11-10 14:25 -0500
            Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-09 20:35 -0500
            Re: all() is slow? Ian Kelly <ian.g.kelly@gmail.com> - 2011-11-09 19:10 -0700
            Re: all() is slow? Ethan Furman <ethan@stoneleaf.us> - 2011-11-10 10:43 -0800
            Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-10 15:37 -0500
              Re: all() is slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-10 23:07 +0000
                Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-10 23:35 -0500
                Re: all() is slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-12 01:18 +0000
                Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-13 01:28 -0500
                Re: all() is slow? alex23 <wuwei23@gmail.com> - 2011-11-13 18:50 -0800
                Re: all() is slow? Devin Jeanpierre <jeanpierreda@gmail.com> - 2011-11-13 23:48 -0500
              Re: all() is slow? "OKB (not okblacke)" <brenNOSPAMbarn@NObrenSPAMbarn.net> - 2011-11-11 05:40 +0000
            Re: all() is slow? Ian Kelly <ian.g.kelly@gmail.com> - 2011-11-10 14:19 -0700
              Re: all() is slow? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-11-10 22:56 +0000
            Re: all() is slow? Ethan Furman <ethan@stoneleaf.us> - 2011-11-10 13:47 -0800
        Re: all() is slow? Chris Angelico <rosuav@gmail.com> - 2011-11-10 10:15 +1100
    Re: all() is slow? Chris Angelico <rosuav@gmail.com> - 2011-11-09 12:19 +1100
    Re: all() is slow? Chris Rebert <clp2@rebertia.com> - 2011-11-08 17:30 -0800
      Re: all() is slow? Hans Mulder <hansmu@xs4all.nl> - 2011-11-09 16:41 +0100
        Re: all() is slow? Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2011-11-09 09:07 -0800
  Re: all() is slow? John Nagle <nagle@animats.com> - 2011-11-09 14:16 -0800
    Re: all() is slow? alex23 <wuwei23@gmail.com> - 2011-11-09 19:52 -0800
    Re: all() is slow? "OKB (not okblacke)" <brenNOSPAMbarn@NObrenSPAMbarn.net> - 2011-11-10 19:35 +0000
  Re: all() is slow? BOOK-AZ <amalguseynov@gmail.com> - 2011-11-15 08:02 -0800

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