Returning a list of indexes of the smallest value in a multidimensional list
<p>This should be simple enough.</p>

<p>I have a multidimensional list of integers, for example:</p>

<pre><code>a = [[5,5,5,4,6],[3,2,6,6,5],[7,2,2,5,6]]
</code></pre>

<p>I need a way to return a list of indexes of the positions with lowest number.  In this example, it would be the indexes corresponding to the value 2, or ((1,1),(2,1),(2,2)).</p>

<p>I'm thinking a list comprehension method, but I'm not sure.</p>
