This question is related to: Python SOAP server / client
In the case of soap with python, there are recommendation to use soaplib (http://wiki.github.com/jkp/soaplib
try to import primitives into your class:
class HelloWorldService(SimpleWSGISoapApp): from soaplib.serializers.primitive import String, Integer, Arraycode @soapmethod(String,Integer,_returns=Array(String))