Clone elements of a list
<p>Let's say I have a Python list that looks like this:</p>

<pre><code>list = [ a, b, c, d]
</code></pre>

<p>I am looking for the most efficient way performanse wise to get this:</p>

<pre><code>list = [ a, a, a, a, b, b, b, c, c, d ]
</code></pre>

<p>So if the list is N elements long then the first element is cloned N-1 times, the second element N-2 times, and so forth...the last element is cloned N-N times or 0 times. Any suggestions on how to do this efficiently on large lists.</p>
