split timestamp by hour
<p>I have a list of timestamps in ISO format</p>

<p><code>[u"2000-01-01T00:00:00+00:00",  u"2000-01-01T00:00:00+00:00",  ...  ]</code></p>

<p>I'm trying to split each string by the hour. However, using <code>"string".strp(":")</code> obviously won't work, because of a <code>too many values to unpack</code> error (due to several :'s) and <code>"string".strp(":%S")</code> gives a value error of <code>more than one value to unpack</code>. 
Any ideas?</p>
