def polygon_jaccard(final_polygons, train_polygons):
    """
    Calcualte the jaccard index of two polygons, based on data type of
    shapely.geometry.MultiPolygon
    :param final_polygons:
    :param train_polygons:
    :return:
    """
    return final_polygons.intersection(train_polygons).area /\
    final_polygons.union(train_polygons).area