<p>Using MVC with an observer pattern, if a user action requires polling a device (such as a camera) for data, should the polling be done in the Controller and the result passed off the Model or should a request be sent to the Model and the Model itself performs the polling.</p>

<p>This question is my attempt to reconcile everything I am reading that touts the "skinny Controllers" maxim with my gut intuition that the Model should only be acting on data not acquiring it.</p>

<p>(Note: This question <em>might</em> be subjective.  I'm not entirely sure that there is a one-true-answer to this question.  If not, feel free to retag as I will be very interested to hear opinions on the subject.)</p>

The syntax you're trying to use is new in
ElementTree 1.3
.
Such version is shipped with
Python 2.7
or higher.
If you have Python 2.6 or less you still have ElementTree 1.2.6 or less.