How to use the pytextrank.pretty_print function in pytextrank

def execute_stage_two(path_stage1):
    """Execute the second stage of processing."""
    graph, ranks = pytextrank.text_rank(os.path.join(PATH_PREFIX, path_stage1))
    pytextrank.render_ranks(graph, ranks)
    path_name_components = path_stage1.split('.')
    path_name_components[path_name_components.index('stage1')] = 'stage2'
    path_stage2 = '-'.join(path_name_components)
    with open(os.path.join(PATH_PREFIX, path_stage2), 'w') as f:
        for rl in pytextrank.normalize_key_phrases(os.path.join(PATH_PREFIX, path_stage1),
                                                   ranks, stopwords=stopwords):
            f.write("%s\n" % pytextrank.pretty_print(rl._asdict()))
    return path_stage2

def execute_stage_one(path_stage0):
    """Execute the first stage of processing."""
    path_stage1 = path_stage0.split('::')[0] + ".stage1.output.dat"
    with open(os.path.join(PATH_PREFIX, path_stage1), 'w') as f:
        for graf in pytextrank.parse_doc(pytextrank.json_iter(
                                         os.path.join(PATH_PREFIX, path_stage0))):
            f.write("%s\n" % pytextrank.pretty_print(graf._asdict()))
    return path_stage1