Hello Michael, that worked well, thank you very much for your aid. I'm just having trouble understanding why I need to do the None check. I thought from my example that weight could'nt be None at all ... could you be so kind to elaborate a bit what's happening behind the scene?
When I tested the WeightType class with a simple example (Person -> weight) it wasn't necessary. Thank you Frank -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.