title: Python How to save reference to a position in a file?
body: <p>I want to be able to save a reference to a character in a file, then go back to it in the future without iterating through the file. For example, I want to save the reference to X in the following file then in the future, immediately jump to it at a later time without iterating through &quot;nfqo fin qoeif ngo gqowe uzoi asdfjis&quot;</p>
  <pre><code>...
  nfqo fin qoeif
  ngo gqowe uzoi
  asdfjis X kajs
  ...
  </code></pre>
  <p>Then I want to get the character following the marked reference, for example:</p>
  <pre><code>saved_reference = X
  third_char = saved_reference + 3 # should return 'a'
  </code></pre>