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Re: How to print something only if it exists?

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On 9/6/2012 1:59 PM, tinnews@isbd.co.uk wrote:
> I want to print a series of list elements some of which may not exist,
> e.g. I have a line:-
>
>       print day, fld[1], balance, fld[2]
>
> fld[2] doesn't always exist (fld is the result of a split) so the
> print fails when it isn't set.

What fails is the indexing operation. You can prevent that by slicing 
rather than indexing: fld[1:2], fld[2:3]. These will give '' if there is 
no fld[1], fld[2]. Whether or not this is sensible depends on what you 
want the output to look like in these cases.

-- 
Terry Jan Reedy

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How to print something only if it exists? tinnews@isbd.co.uk - 2012-09-06 18:59 +0100
  Re: How to print something only if it exists? Emile van Sebille <emile@fenx.com> - 2012-09-06 11:19 -0700
  Re: How to print something only if it exists? Dave Angel <d@davea.name> - 2012-09-06 14:18 -0400
    Re: How to print something only if it exists? tinnews@isbd.co.uk - 2012-09-08 11:02 +0100
      Re: How to print something only if it exists? Dave Angel <d@davea.name> - 2012-09-08 07:08 -0400
  Re: How to print something only if it exists? Terry Reedy <tjreedy@udel.edu> - 2012-09-06 15:34 -0400
  Re: How to print something only if it exists? Hans Mulder <hansmu@xs4all.nl> - 2012-09-07 11:37 +0200
  Re: How to print something only if it exists? Roy Smith <roy@panix.com> - 2012-09-07 09:16 -0400
  RE: How to print something only if it exists? "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-09-13 17:48 +0000

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