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

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On 10/13/2014 10:38 AM, Rff wrote:
> 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?
>
>
> Thanks,

Read in your lines, keeping a counter as you go.  "Select" those lines 
whose counter is even (or odd -- you didn't say which you wanted).

So now some questions for you:

  * Do you know how to open a file and read in all the lines?
  * Do you know how to count as you do so?
  * Do you know how to test for evenness?   (Use count%2 will be zero
    for even count values.)
  * Do you know how to write lines to an output file?

Gary Herron

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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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