Python sets and interesction
<p>I am using pythin 2.5.4.  From here: <a href="http://stackoverflow.com/questions/3852780/python-intersection-of-multiple-lists">Python -Intersection of multiple lists?</a></p>

<p>I have this:</p>

<pre><code>def intersect(*d):
    sets = iter(map(set, d))
    result = sets.next()
    for s in sets:
        result = result.intersection(s)
    return result
</code></pre>

<p>The following works as expected:</p>

<pre><code>intersect([1,2,3,4], [2,3,4], [3,4,5,6,7])
</code></pre>

<p>But, I have something that looks more like the following:</p>

<pre><code>d=[ [1,2,3,4], [2,3,4], [3,4,5,6,7] ]
</code></pre>

<p>If I call it like</p>

<pre><code>intersect(d)
</code></pre>

<p>I get </p>

<pre><code>TypeError: list objects are unhashable
</code></pre>

<p>How do I transform <code>d</code> above into something <code>intersect()</code> can take?</p>
