Try to deal with this warning/error: DeprecationWarning: generator 'iter_roles' raised StopIteration PEP479 specifies how to rework it by using return rather than raise StopIteration. I am not sure if this is right, but test/test_cgi.py::FormTestCase::testRoles is still passing.

try:
    # Python 3+.
    from xmlrpc import client, server
    server.SimpleXMLRPCDispatcher
except (ImportError, AttributeError):
    # Python 2.
    import xmlrpclib as client
    import SimpleXMLRPCServer as server