[Zope] testing for property

[Tom Cameron]

I am trying to write a script that upgrades instances of a class. I have
added new properties to my python product Class and I wish to run a method
to check the old instances and add properties if necessary.

I find that when I use the hasProperty('propname') method it always returns
true.

It appears that this method checks the 'Class' and not the actual
'Instances' for the existance of a property. So if I upgrade my class, I
cant use this method to check for instances that are missing properties.

Is this true??

It appears I have to actually raise an error to check for a property

try:
  print instance.property
else:
  instance.property=''

This seems a bit silly. Am I doing anything wrong here

Tom