Average timedelta in list
<p>I want to calculate the avarage timedelta between dates in a list.
Although the following works well, I'm wondering if there's a smarter way?</p>

<pre><code>delta = lambda last, next: (next - last).seconds + (next - last).days * 86400   
total = sum(delta(items[i-1], items[i]) for i in range(1, len(items)))
average = total / (len(items) - 1)
</code></pre>
