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


Groups > comp.lang.python > #88186

Re: Supply condition in function call

Date 2015-03-28 09:55 +1100
From Cameron Simpson <cs@zip.com.au>
Subject Re: Supply condition in function call
References <87twx6qkdz.fsf@uriel.graune.org>
Newsgroups comp.lang.python
Message-ID <mailman.281.1427496970.10327.python-list@python.org> (permalink)

Show all headers | View raw


On 27Mar2015 21:02, Manuel Graune <manuel.graune@koeln.de> wrote:
>Cameron Simpson <cs@zip.com.au> writes:
>
>> This passes the local variables inside test1() to "condition" as a
>> single parameter. Now, I grant that vars['i'] is a miracle of
>> tediousness. So consider this elaboration:
>>
>>  from collections import namedtuple
>>
>>  condition_test = lambda vars: vars.i + vars.j > 4
>>
>>  def test1(a, b, condition):
>>    for i, j in zip(a,b):
>>      c = i + j
>>      vars = locals()
>>      varnames = list(vars.keys())
>>      varstupletype = namedtuple("locals", varnames)
>>      varstuple = varstupletype(*[ vars[k] for k in varnames ])
>>      if condition(varstuple):
>>        print("Foo")
>>
>> Here, the condition_test function/lambda uses "vars.i" and "vars.j",
>> which i think you'll agree is easier to read and write. The price is
>> the construction of a "namedtuple" to hold the variable name
>> values. See:
>>
>>  https://docs.python.org/3/library/collections.html#collections.namedtuple
>>
>
>This is probably getting off topic,

I think it is on topic.

>but is there any relevant difference
>or benefit to using namedtuple instead of something like types.SimpleNamespace?
>
>https://docs.python.org/3/library/types.html#additional-utility-classes-and-functions

Probably not. SimpleNamespace is much easier to construct; I hadn't thought of 
it. As the doc remarks, a namedtuple is probably better for fixed records (eg 
mapping out rows of a CSV file) because it will prevent you using the wrong 
name. But for a comparison function SimpleNamespace is probably better.

Cheers,
Cameron Simpson <cs@zip.com.au>

The Horn of Vengeance: When he pushes the horn button, the device produces
the sound of fingernails scraping on a blackboard, amplified beyond pain
threshold.  If that doesn't work, the horn then plays the Pina Colada song.

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


Thread

Supply condition in function call Manuel Graune <manuel.graune@koeln.de> - 2015-03-25 18:29 +0100
  Re: Supply condition in function call Joel Goldstick <joel.goldstick@gmail.com> - 2015-03-25 13:41 -0400
    Re: Supply condition in function call Manuel Graune <manuel.graune@koeln.de> - 2015-03-25 18:51 +0100
      Re: Supply condition in function call Joel Goldstick <joel.goldstick@gmail.com> - 2015-03-25 14:17 -0400
      Re: Supply condition in function call Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 12:22 -0600
      Re: Supply condition in function call Joel Goldstick <joel.goldstick@gmail.com> - 2015-03-25 14:42 -0400
  Re: Supply condition in function call Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 11:44 -0600
    Re: Supply condition in function call Grant Edwards <invalid@invalid.invalid> - 2015-03-25 19:53 +0000
      Re: Supply condition in function call Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-25 14:49 -0600
        Re: Supply condition in function call Grant Edwards <invalid@invalid.invalid> - 2015-03-26 15:41 +0000
  Re: Supply condition in function call Terry Reedy <tjreedy@udel.edu> - 2015-03-25 14:50 -0400
  Re: Supply condition in function call Gary Herron <gherron@digipen.edu> - 2015-03-25 12:13 -0700
    Re: Supply condition in function call Rustom Mody <rustompmody@gmail.com> - 2015-03-25 21:02 -0700
      Re: Supply condition in function call Chris Angelico <rosuav@gmail.com> - 2015-03-26 17:00 +1100
        Re: Supply condition in function call Rustom Mody <rustompmody@gmail.com> - 2015-03-26 18:41 -0700
          Re: Supply condition in function call Chris Angelico <rosuav@gmail.com> - 2015-03-27 12:56 +1100
            Re: Supply condition in function call Rustom Mody <rustompmody@gmail.com> - 2015-03-26 19:21 -0700
              Re: Supply condition in function call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-27 15:34 +1100
                Re: Supply condition in function call Rustom Mody <rustompmody@gmail.com> - 2015-03-27 06:48 -0700
                Re: Supply condition in function call Chris Angelico <rosuav@gmail.com> - 2015-03-28 01:17 +1100
                Re: Supply condition in function call Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-27 16:00 +0000
                Re: Supply condition in function call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-28 18:32 +1100
                Re: Supply condition in function call Chris Angelico <rosuav@gmail.com> - 2015-03-28 18:45 +1100
            Re: Supply condition in function call Larry Hudson <orgnut@yahoo.com> - 2015-03-27 17:26 -0700
              Re: Supply condition in function call Rustom Mody <rustompmody@gmail.com> - 2015-03-27 18:27 -0700
              Re: Supply condition in function call Marko Rauhamaa <marko@pacujo.net> - 2015-03-28 09:50 +0200
                Re: Supply condition in function call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-28 20:17 +1100
                Re: Supply condition in function call Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-28 03:19 -0600
                Re: Supply condition in function call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-28 20:57 +1100
                Re: Supply condition in function call Cameron Simpson <cs@zip.com.au> - 2015-03-30 09:35 +1100
                Re: Supply condition in function call Manuel Graune <manuel.graune@koeln.de> - 2015-03-30 00:46 +0200
          Re: Supply condition in function call Ian Kelly <ian.g.kelly@gmail.com> - 2015-03-26 20:25 -0600
            Re: Supply condition in function call Rustom Mody <rustompmody@gmail.com> - 2015-03-26 19:46 -0700
    Re: Supply condition in function call Manuel Graune <manuel.graune@koeln.de> - 2015-03-26 07:27 +0100
      Re: Supply condition in function call Cameron Simpson <cs@zip.com.au> - 2015-03-26 18:06 +1100
        Re: Supply condition in function call Manuel Graune <manuel.graune@koeln.de> - 2015-03-27 21:02 +0100
          Re: Supply condition in function call Cameron Simpson <cs@zip.com.au> - 2015-03-28 09:55 +1100
      Re: Supply condition in function call Peter Otten <__peter__@web.de> - 2015-03-26 10:03 +0100
        Re: Supply condition in function call Manuel Graune <manuel.graune@koeln.de> - 2015-03-27 20:46 +0100
          Re: Supply condition in function call Peter Otten <__peter__@web.de> - 2015-03-27 21:38 +0100
  Re: Supply condition in function call smap <askme.first@thankyouverymuch.invalid> - 2015-03-28 08:58 +0000

csiph-web