title: Reusing variables in Python
body: <p>In Python, I often reuse variables in manner analogous to this:</p>
  
  <pre><code>files = files[:batch_size]
  </code></pre>
  
  <p>I like this technique because it helps me cut on the number of variables I need to track.</p>
  
  <p>Never had any problems but I am wondering if I am missing potential downsides e.g. performance etc.</p>