title: Equivalent for pop on strings
body: <p>Given a very large string. I would like to process parts of the string in a loop like this:</p>
  
  <pre><code>large_string = "foobar..."
  while large_string:
      process(large_string.pop(200))
  </code></pre>
  
  <p>What is a nice and efficient way of doing this?</p>