Python will not understand List <p>Sorry I have a very basic python question. In the following program I'm trying to duplicate a list and then sort it in ascending order. The code I've written is:</p> <pre><code>def lesser_than(thelist): duplicate = thelist[:] duplicate = duplicate.sort() return duplicate </code></pre> <p>The error it gives me is that it cannot sort something of the type None. Does anyone know why this is happening?</p>