'Group function arguments into categories.'

def _partition_args(self, args):

    py_in = []
    py_out = []
    for arg in args:
        if isinstance(arg, OutputArgument):
            py_out.append(arg)
        elif isinstance(arg, InOutArgument):
            raise ValueError("Ufuncify    doesn't    support    InOutArguments")
        else:
            py_in.append(arg)
    return (py_in, py_out)
