def root_to_numpy(base_object, field_name, attributes):
    """Convert objects stored in base_object.field_name to numpy array
    Will query attributes for each of the objects in base_object.field_name
    No, root_numpy does not do this for you, that's for trees...
    """
    objects_to_convert = getattr(base_object, field_name)
    if not len(objects_to_convert):
        return None
    return np.array([tuple([getattr(p, pa) for pa in attributes]) for p in objects_to_convert])