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Date: Mon, 13 Oct 2014 10:50:43 -0700
From: Gary Herron <gary.herron@islandtraining.com>
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Subject: 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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<html>
  <head>
    <meta content=3D"text/html; charset=3Dwindows-1252"
      http-equiv=3D"Content-Type">
  </head>
  <body bgcolor=3D"#FFFFFF" text=3D"#000000">
    <div class=3D"moz-cite-prefix">On 10/13/2014 10:38 AM, Rff wrote:<br>=

    </div>
    <blockquote
      cite=3D"mid:3be64ca8-d2e7-493a-b4f3-ef114f581450@googlegroups.com"
      type=3D"cite">
      <pre wrap=3D"">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,
</pre>
    </blockquote>
    <br>
    Read in your lines, keeping a counter as you go.=A0 "Select" those
    lines whose counter is even (or odd -- you didn't say which you
    wanted).<br>
    <br>
    So now some questions for you:<br>
    <ul>
      <li>Do you know how to open a file and read in all the lines?</li>
      <li>Do you know how to count as you do so?</li>
      <li>Do you know how to test for evenness?=A0=A0 (Use count%2 will b=
e
        zero for even count values.)</li>
      <li>Do you know how to write lines to an output file?</li>
    </ul>
    Gary Herron<br>
    <br>
  </body>
</html>

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