title: How to replace substring with another substring (by index from..to)
body: <p>How I can replace substring from some character to another by other string?</p>
  
  <pre><code>first = 4
  last = 11
  replacement = '...'
  'show me the money'.replace_part(first, last, replacement)
  # =&gt; 'show...money'
  </code></pre>