I'm using xmlrpclib from a standalone Python script to post articles to Squishdot. It seems that calls to methods that return strings work fine, while calls to other methods fail with tracebacks like the following:

Traceback (innermost last): File "./postToControlCom.py", line 77, in ? postMessage(msg) File "./postToControlCom.py", line 68, in postMessage summary, subject, "Automation List") File "./xmlrpclib.py", line 547, in __call__ return self.__send(self.__name, args) File "./xmlrpclib.py", line 630, in __request request File "./xmlrpclib.py", line 582, in request headers xmlrpclib.ProtocolError: <ProtocolError for silver.control.com/zope/: 500 Internal Server Error>

.....

# if a method called by it doesn't return a string. # This is bogus, but: return 'Done'

BTW: all of this appears to me to be true whether or not Squishdot is involved -- I have tested with target methods that are not part of it.

What am I doing wrong here?

Obviously xmlrpclib needs to be able to marshal the return value back to the caller. The xmlrpc spec has no equivalent of the 'None' that results from a returnless function in python, hence the error. The return values does not have to be a string; just something that xmlrpc understands.