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Groups > comp.lang.python > #79060

Re: How to select every other line from a text file?

From Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject Re: How to select every other line from a text file?
Date 2014-10-13 19:02 +0100
References <3be64ca8-d2e7-493a-b4f3-ef114f581450@googlegroups.com> <m1h39u$412$1@reader1.panix.com>
Newsgroups comp.lang.python
Message-ID <mailman.14828.1413223364.18130.python-list@python.org> (permalink)

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On 13/10/2014 18:48, John Gordon wrote:
> In <3be64ca8-d2e7-493a-b4f3-ef114f581450@googlegroups.com> Rff <rwang@avnera.com> writes:
>
>> Hi,
>> I have a text file. Now it is required to select every other line of that
>> text to generate a new text file. I have read through Python grammar, but
>> still lack the idea at the beginning of the task. Could you tell me some
>> methods to get this?
>
> Initialize a counter variable to zero.  (Or one, depending if you want to
> select odd or even lines.)
>
> Each time you read a line from the file, add one to the counter.
>
> If the counter is odd, process the line; otherwise use the 'continue'
> statement to start the loop over and read another line.
>

Why bother to initialise a counter when you can get the enumerate 
function to do all the work for you?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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Thread

How to select every other line from a text file? Rff <rwang@avnera.com> - 2014-10-13 10:38 -0700
  Re: How to select every other line from a text file? Chris Angelico <rosuav@gmail.com> - 2014-10-14 04:46 +1100
    Re: How to select every other line from a text file? Grant Edwards <invalid@invalid.invalid> - 2014-10-13 19:04 +0000
  Re: How to select every other line from a text file? John Gordon <gordon@panix.com> - 2014-10-13 17:48 +0000
    Re: How to select every other line from a text file? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-10-13 19:02 +0100
    Re: How to select every other line from a text file? emile <emile@fenx.com> - 2014-10-13 11:11 -0700
    Re: How to select every other line from a text file? Joel Goldstick <joel.goldstick@gmail.com> - 2014-10-13 14:45 -0400
    Re: How to select every other line from a text file? Tim Chase <python.list@tim.thechases.com> - 2014-10-13 14:12 -0500
    Re: How to select every other line from a text file? emile <emile@fenx.com> - 2014-10-13 13:01 -0700
  Re: How to select every other line from a text file? Gary Herron <gary.herron@islandtraining.com> - 2014-10-13 10:50 -0700
  Re: How to select every other line from a text file? Tim Chase <python.list@tim.thechases.com> - 2014-10-13 12:55 -0500
  Re: How to select every other line from a text file? Denis McMahon <denismfmcmahon@gmail.com> - 2014-10-13 23:54 +0000
  Re: How to select every other line from a text file? Dan Stromberg <drsalists@gmail.com> - 2014-10-13 17:34 -0700

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