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

Groups > comp.lang.python > #83318

Re: Comparisons and sorting of a numeric class....

Show all headers | View raw

Steven D'Aprano <steve+comp.lang.python@pearwood.info>:

> Marko Rauhamaa wrote:
>> I prefer the Scheme way:
>>    #f is a falsey object
>>    everything else is a truthy object
>
> The Scheme way has no underlying model of what truthiness represents, just
> an arbitrary choice to make a single value have one truthiness, and
> everything else the other. It's just as meaningless and just as arbitrary
> as the opposite would be:
>
>     #t is True
>     everything else is falsey
> [...]
> I'd rather the Pascal way:
>
>     #t is True
>     #f is False
>     everything else is an error

An advantage of the Scheme way is the chaining of "and" and "or". For
example, this breaks in Python:

   def dir_contents(path):
       if os.path.isdir(path):
           return os.listdir(path)
       return None

   def get_choices():
       return dir_contents(PRIMARY) or \
           dir_contents(SECONDARY) or \
           [ BUILTIN_PATH ]


Marko

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

Thread

Re: Comparisons and sorting of a numeric class.... Andrew Robinson <andrew3@r3dsolutions.com> - 2015-01-06 18:01 -0800
  Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve@pearwood.info> - 2015-01-07 08:10 +0000
    Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-07 19:21 +1100
    Re: Comparisons and sorting of a numeric class.... Marko Rauhamaa <marko@pacujo.net> - 2015-01-07 12:01 +0200
      Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-08 10:46 +1100
        Re: Comparisons and sorting of a numeric class.... Marko Rauhamaa <marko@pacujo.net> - 2015-01-08 08:21 +0200
          Re: Comparisons and sorting of a numeric class.... Ian Kelly <ian.g.kelly@gmail.com> - 2015-01-08 07:57 -0700
            Re: Comparisons and sorting of a numeric class.... Marko Rauhamaa <marko@pacujo.net> - 2015-01-08 21:41 +0200
          Re: Comparisons and sorting of a numeric class.... Chris Kaynor <ckaynor@zindagigames.com> - 2015-01-08 10:44 -0800
            Re: Comparisons and sorting of a numeric class.... Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-01-09 23:27 +1100
              Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-09 23:43 +1100
                Re: Comparisons and sorting of a numeric class.... Marko Rauhamaa <marko@pacujo.net> - 2015-01-09 16:28 +0200
                Re: Comparisons and sorting of a numeric class.... Paul Rubin <no.email@nospam.invalid> - 2015-01-09 07:06 -0800
                Re: Comparisons and sorting of a numeric class.... Chris Angelico <rosuav@gmail.com> - 2015-01-10 02:14 +1100
                Re: Comparisons and sorting of a numeric class.... Marko Rauhamaa <marko@pacujo.net> - 2015-01-09 17:16 +0200

csiph-web