def translate_field(label, translator_map, **kwargs):
    """
    Translate field with an old label into a list of tuples of form (new_label, new_value).
    :param translator_map - maps labels to appropriate tuple lists. Supplied by parsing script.
    For each label we get a list of tuples (new_label, mapping_function). Mapping_function invoked
    in the arguments yields the new value.
    :param kwargs - keyword style arguments passed into mapping functions for
    calculating the new values. May be arbitrarily long.
    """
    try:
        new_label_list = []
        label_list = translator_map[label]
        for (new_label, map_function) in label_list:
            new_label_list.append((new_label, map_function(**kwargs)))
    except KeyError:
        raise ValueError("Unknown label")
    return new_label_list