stanford-nlp - PythonでCoreNLPサーバーの返された文字列から解析ツリーを取得するには?

Question

私はcorenlpサーバーでpycorenlpを使用しています。文字列形式で解析木を取得できます。しかし、NLTK ライブラリのようにツリーとして取得できますか?

from pycorenlp import StanfordCoreNLP
import pprint
import nltk

nlp = StanfordCoreNLP('http://localhost:9000')

text = ('Purgrug Vobter and Juklog Qligjar vruled into the Battlefield. Vobter was about to Hellfire. Juklog Qligjar started kiblaring.')

output = nlp.annotate(text, properties={
'annotators': 'tokenize,ssplit,pos,depparse,parse',
'outputFormat': 'json'
})


print [s['parse'] for s in output['sentences']]

出力：

[u'(ROOT\r\n  (S\r\n    (NP (NNP Purgrug) (NNP Vobter)\r\n      (CC and)\r\n      (NNP Juklog) (NNP Qligjar))\r\n    (VP (VBD vruled)\r\n      (PP (IN into)\r\n        (NP (DT the) (NN Battlefield))))\r\n    (. .)))', u'(ROOT\r\n  (S\r\n    (NP (NNP Vobter))\r\n    (VP (VBD was)\r\n      (ADJP (IN about)\r\n        (PP (TO to)\r\n          (NP (NNP Hellfire)))))\r\n    (. .)))', u'(ROOT\r\n  (S\r\n    (NP (NNP Juklog) (NNP Qligjar))\r\n    (VP (VBD started)\r\n      (S\r\n        (VP (VBG kiblaring))))\r\n    (. .)))']