hello, I am am worrying a problem here, where I need to store references to objects in my own objects, while at the same time needing to store and retreive my objects later. Here is an example of what I need to do: in a product BooTool for Zope I have: ---- class Foo: def __init__(self, data, ref_a): self.data = data self.a_handle = ref_a self.stuff = [] def bar(self): # do something with self.stuff cool = self.a_handle('one') self.stuff.append(cool) return self.stuff def getStuff(data, ref_a): """ his method is available to Zope from the tool boo_tool """ return Foo(data, ref_a) ---- in a python script I have a pythonscript: ---- my_ob = context.boo_tool.getStuff('123', container.my_script) return my_ob ---- so my_ob contains a reference to the my_script Pythonscript/ZSQL Method. What happens if I store my_ob in a session storage for instance and later retrieve it and do my_ob.bar() ? What bad things can happen? Thanks for any input. /dario -- -- ------------------------------------------------------------------- Dario Lopez-Kästen, IT Systems & Services Chalmers University of Tech.