[Twisted-Python] getting "can't serialize output " error while returning numeric data from postgresql.

[Krishnakant]

hello all,
I think this must be a simple thing and many of you might be knowing the
solution,
But I am new to twisted and for me this is a big challenge.
I am connecting my xmlrpc based twisted application (server ) to a
postgresql database using python-psycopg2
I am returning a result set from a function and the resultset is as a
list which cursor.fetchone() returns.
now  my function called xmlrpc_getDetails(product_code):
   #code to execute query on cursur 
   return resultset

All works well untill i encounter a field of type numeric which has
decimal values.

I et the can't serialize output error.
I believe I have to register some kind of a system to cast the data in a
way that twisted understands?
how can I do this?
happy hacking.
Krishnakant.