Not successfully in appending an element to the list (Python) : <p>Not sure why the append function returns 'None" in following code</p>

<pre><code>dw=[1,3,5]
dw=[0]+dw
print(dw,type(dw))
dw=dw.append(12)
print(dw)
</code></pre>

<p>Output is: ([0, 1, 3, 5],'list'), None.</p>

<p>Why not [0,1,3,5,12] with append function?</p>

<p>Thanks;</p>
