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Groups > comp.lang.python > #92533

Re: zip as iterator and bad/good practices

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On 06/12/2015 05:26 PM, Ian Kelly wrote:
>> for stuff, branch in zip(stuffs, branches):
>> >         # compute flux
>> >         ...
>> >         # add to the downstream branch
>> >         id_branch = branches.index(branch.flows_to)
>> >         branches[id_branch].property.append(stuff_i_computed)
> Er, I don't see the problem here. The branch object in the zip list
> and the branch object in branches should be the*same*  object, so the
> downstream branch update should be reflected when you visit it later
> in the iteration, regardless of whether zip returns a list or an iterator.
>
> Tangentially, unless you're using id_branch for something else that
> isn't shown here, is it really necessary to search the list for the
> downstream branch when it looks like you already have a reference to
> it? Could the above simply be replaced with:
>
>      branch.flows_to.property.append(stuff_i_computed)

Thanks a lot for your careful reading! I overly simplified my example 
and indeed this line works fine. I was adding things to "stuffs" too, 
which is a list of lists... Sorry for the confusion!

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zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:00 +0200
  Re: zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:05 +0200
  Re: zip as iterator and bad/good practices Ian Kelly <ian.g.kelly@gmail.com> - 2015-06-12 09:26 -0600
    Re: zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:34 +0200
    Re: zip as iterator and bad/good practices Fabien <fabien.maussion@gmail.com> - 2015-06-12 17:59 +0200
  Re: zip as iterator and bad/good practices Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-06-12 17:22 +0100
  Re: zip as iterator and bad/good practices Laura Creighton <lac@openend.se> - 2015-06-12 22:34 +0200
  Re: zip as iterator and bad/good practices Terry Reedy <tjreedy@udel.edu> - 2015-06-12 19:27 -0400
  Re: zip as iterator and bad/good practices Terry Reedy <tjreedy@udel.edu> - 2015-06-12 19:43 -0400
    Re: zip as iterator and bad/good practices sohcahtoa82@gmail.com - 2015-06-12 17:02 -0700
      Re: zip as iterator and bad/good practices Chris Angelico <rosuav@gmail.com> - 2015-06-13 10:26 +1000
        Re: zip as iterator and bad/good practices sohcahtoa82@gmail.com - 2015-06-12 17:39 -0700
  Re: zip as iterator and bad/good practices jimages <jimages123@gmail.com> - 2015-06-13 13:32 +0800
    Re: zip as iterator and bad/good practices Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-13 07:17 +0000
      Re: zip as iterator and bad/good practices Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2015-06-13 13:48 +0100
        Re: zip as iterator and bad/good practices Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-06-13 16:16 +0000

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