title: Replace first occurrence only of a string?
body: <p>I have something like this:</p>
  
  <pre><code>text = 'This text is very very long.'
  replace_words = ['very','word']
  
  for word in replace_words:
      text = text.replace('very','not very')
  </code></pre>
  
  <p>I would like to only replace the first 'very' or choose which 'very' gets overwritten. I'm doing this on much larger amounts of text so I want to control how duplicate words are being replaced.</p>