[Zope] Problem with Python Script in RAM Cache

[Peter Baeuerle]

I wanted to cache a Python script in the ZOPE ram cache manager, but it did not
work. I did hear that "RAM cache manager can only cache picklable objects". I do
not understand, what that means. I heard that a dictionary would be a
"picklable" object.
My script returns a sequence (actually the results from a search in the PLONE
catalog by the searchresults method). Does that mean, I would have to change my
python script so that it would return a dictionary instead of a sequence to be
able to be cached by a ram cache manager?
Can anybody help me? 

Thanks
Peter Baeuerle