如何使用 stanford NLP 解析 Penn Tree Bank 并获取所有子树？

【问题标题】：How to parse Penn Tree Bank and get all the child trees using stanford NLP?如何使用 stanford NLP 解析 Penn Tree Bank 并获取所有子树？
【发布时间】：2016-05-26 00:32:52
【问题描述】：

有没有办法解析下面的PTB树得到所有的子树例如：

Text   :  Today is a nice day.
PTB : (3 (2 Today) (3 (3 (2 is) (3 (2 a) (3 (3 nice) (2 day)))) (2 .)))

需要所有可能的子树

Output  : 
(3 (2 Today) (3 (3 (2 is) (3 (2 a) (3 (3 nice) (2 day)))) (2 .)))
(2 Today)
(3 (3 (2 is) (3 (2 a) (3 (3 nice) (2 day)))) (2 .))
(3 (2 is) (3 (2 a) (3 (3 nice) (2 day))))
(3 (2 is) (3 (2 a) (3 (3 nice) (2 day))))
(2 is)
(3 (2 a) (3 (3 nice) (2 day)))
(2 a)
(3 (3 nice) (2 day))
(3 nice)
(2 day)
(2 .)

【问题讨论】：

标签： java parsing nlp stanford-nlp

【解决方案1】：

此演示的输入文件应该是每行一棵树的一个字符串表示形式。此示例打印出第一棵树的子树。

Stanford CoreNLP 感兴趣的课程是 Tree。

import edu.stanford.nlp.trees.*;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.*;

public class TreeLoadExample {

    public static void printSubTrees(Tree t) {
        if (t.isLeaf())
            return;
        System.out.println(t);
        for (Tree subTree : t.children()) {
            printSubTrees(subTree);
        }
    }


    public static void main(String[] args) throws IOException, FileNotFoundException,
            UnsupportedEncodingException {
        TreeFactory tf = new LabeledScoredTreeFactory();
        Reader r = new BufferedReader(new InputStreamReader(new FileInputStream(args[0]), "UTF-8"));
        TreeReader tr = new PennTreeReader(r, tf);
        Tree t = tr.readTree();
        printSubTrees(t);
    }
}

【讨论】：