regex - 如何对 NLP 解析树进行逆向工程以得到原始句子？

Question

给定一个解析树(通过 http://nlp.stanford.edu:8080/corenlp/process pretty-print 选项获得)

(ROOT (S (NP (PRP You)) (VP (MD could) (VP (VB say) (SBAR (IN that) (S (NP (PRP they)) (ADVP (RB regularly)) (VP (VB catch) (NP (NP (DT a) (NN shower)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ adds) (PP (TO to) (NP (NP (PRP$ their) (NN exhilaration)) (CC and) (NP (FW joie) (FW de) (FW vivre))))))))))))) (. .)))

我怎样才能得出原来的句子？

You could say that they regularly catch a shower, which adds to their exhilaration and joie de vivre.

我正在考虑使用一些正则表达式魔法，但我想知道 Stanford NLP 是否有内置功能来完成这项任务？

Answer 1

您可以使用 Tree.fromstring() 将字符串转换为 Tree。现在，您可以使用 Tree.leaves() 方法从树中获取所有标记。

代码:

from nltk import Tree

parse_str = "(ROOT (S (NP (PRP You)) (VP (MD could) (VP (VB say) (SBAR (IN that) (S (NP (PRP they)) (ADVP (RB regularly)) (VP (VB catch) (NP (NP (DT a) (NN shower)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ adds) (PP (TO to) (NP (NP (PRP$ their) (NN exhilaration)) (CC and) (NP (FW joie) (FW de) (FW vivre))))))))))))) (. .)))"

t = Tree.fromstring(parse_str)

#print t.leaves()
print ' '.join(t.leaves())

输出:

You could say that they regularly catch a shower , which adds to their exhilaration and joie de vivre .