list union with duplicates
<p>I need to unite two lists in Python3,where duplicates can exist,and for one set of these the resulting list will contain as many as max in both lists.An example might clarify it:</p>

<pre><code>[1,2,2,5]( some operator)[2,5,5,5,9]=[1,2,2,5,5,5,9]
</code></pre>

<p>Ideas?</p>
