title: How to read a specific line which is above the current line from a file using python
body: <p>I have a file, after reading a line from the file I have named it <code>current_line</code>, I want to fetch the 4th line above the current_line. How can this be done using python?</p>
  
  <pre><code>line 1
  line 2
  line 3
  line 4
  line 5
  line 6
  </code></pre>
  
  <p>Now  say I have fetched line 6 and I have made</p>
  
  <pre><code>current_line = line 6
  </code></pre>
  
  <p>Now i want 4 the line from above (ie) N now want line 2 </p>
  
  <pre><code>output_line = line 2
  </code></pre>
  
  <p>PS: I dont want to read the file from bottom.</p>