Python, why does this sum function not work
<p>Why does this sum  function not work? It's intent is to sum the variable items in a list</p>

<pre><code>    def sum_list (a_list):
        length= len(a_list)
        counter = 0
        total= 0

        while(counter &lt; length):

             (a_list[counter] +total)          
             total = total + counter
        counter = counter + 1
        return total      



#testing the functions
my_list = [3,3,3]
print sum_list(my_list)
</code></pre>
