[Zope] Simple: Update a ZClass property via Python Script

[Jeremy Cowgar]

I have just finished the ZooExhibit product tutorial. It checks the property 
of a ZClass, last_meal_time to see if the animal is hungry. If so, I want to 
feed it (practice). So, I created a python script with a link to it inside 
the <dtml-if isHungry> area, and in it I have:

manage_changeProperties(last_meal_time, '2002-01-01')

It runs just fine, but my property is not updated. How can I update this 
property?

Thanks!

Jeremy Cowgar