title: Python 3, Negative seek() Problem with Terrabyte Text File,
body: <p>I'm in the middle of a very large text file (nowhere near the EOF) opened like so:</p>
  <pre><code>    iFile = open('big.csv', 'rb')
  </code></pre>
  <p>The good thing is that each line of data has the same length. So, moving FORWARD through the file is simply a multiple of that line length in bytes.</p>
  <p>I need to avoid having to move to the beginning of the file, then traversing the data to where I was, only a few lines above the previous processing point.</p>
  <p>I only see two options:</p>
  <ol>
  <li>utilize a iFile.seek(-425 * 8, 1) call, which will apparently NOT work in Python 3... (it throws a &quot;io.UnsupportedOperation: can't do nonzero cur-relative seeks&quot; error)</li>
  </ol>
  <p>OR</p>
  <ol start="2">
  <li>perform a seek(0), then perform a seek() to the location where I want to be.</li>
  </ol>
  <p>Is there a third alternative that I'm not considering?</p>
  <p>Thanks in advance for any insight... I'm stumped.</p>