title: First argument of sys.path.insert in python
body: <p>Some examples show</p>
  <pre><code>sys.path.insert(0, &quot;path/to/whatever&quot;)
  </code></pre>
  <p>and other examples show</p>
  <pre><code>sys.path.insert(1, &quot;path/to/whatever&quot;).
  </code></pre>
  <p>But I could not find any information of regarding the effect of using 0 as opposed to 1 and vice versa, for the first input argument of the insert() function.</p>
  <p><strong>Where can I find official documentation regarding this?</strong></p>
  <p><strong>Also what is the difference between the two?</strong></p>