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Groups > comp.lang.python > #82409

Re: Extension of while syntax

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On 12/11/2014 9:21 PM, Nelson Crosby wrote:
> I was thinking a bit about the following pattern:
>
> value = get_some_value()
> while value in undesired_values:
>      value = get_some_value()

This is do_while or do_until.  In Python, write it as do_until in this form.

while True:
     value = get_some_value()
     if value not in undesired_values:
         break

> I've always hated code that looks like this. Partly due to the repetition,
> but partly also due to the fact that without being able to immediately
 > recognise this pattern, it isn't very readable.

The repetitiion is easily eliminated.

> value = get_some_value() while value in undesired_values()

Forget this, or anything like it, as a 'serious' proposal.

-- 
Terry Jan Reedy

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Thread

Extension of while syntax Nelson Crosby <nc@sourcecomb.com> - 2014-12-11 18:21 -0800
  Re: Extension of while syntax Ben Finney <ben+python@benfinney.id.au> - 2014-12-12 13:37 +1100
  Re: Extension of while syntax Chris Angelico <rosuav@gmail.com> - 2014-12-12 13:38 +1100
    Re: Extension of while syntax Marko Rauhamaa <marko@pacujo.net> - 2014-12-12 09:10 +0200
      Re: Extension of while syntax Chris Angelico <rosuav@gmail.com> - 2014-12-12 18:38 +1100
        Re: Extension of while syntax Marko Rauhamaa <marko@pacujo.net> - 2014-12-12 10:25 +0200
      Re: Extension of while syntax cl@isbd.net - 2014-12-12 09:09 +0000
        Re: Extension of while syntax Marko Rauhamaa <marko@pacujo.net> - 2014-12-12 12:33 +0200
  RE: Extension of while syntax "Clayton Kirkwood" <crk@godblessthe.us> - 2014-12-11 18:59 -0800
  Re: Extension of while syntax Terry Reedy <tjreedy@udel.edu> - 2014-12-11 22:00 -0500
  Re: Extension of while syntax Ben Finney <ben+python@benfinney.id.au> - 2014-12-12 14:14 +1100
  Re: Extension of while syntax Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-12-12 08:00 +0000
  Re: Extension of while syntax Chris Angelico <rosuav@gmail.com> - 2014-12-12 19:05 +1100
  Re: Extension of while syntax Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-12-12 11:38 -0500
  Re: Extension of while syntax Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-12-13 22:56 +1100

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