如何遍历树的所有节点?
问题描述:
我想简化我的分析树的节点,即给出一个节点,我摆脱了第一个连字符以及连字符之后的任何内容。例如,如果一个节点是NP-TMP-FG,我想使它成为NP,如果它是SBAR-SBJ,我想使它成为SBAR等等。这是我有一个解析树的例子如何遍历树的所有节点?
((S (S-TPC-2 (NP-SBJ (NP (DT The) (NN asbestos) (NN fiber)) (, ,)
(NP (NN crocidolite)) (, ,)) (VP (VBZ is) (ADJP-PRD (RB unusually) (JJ resilient))
(SBAR-TMP (IN once) (S (NP-SBJ (PRP it)) (VP (VBZ enters) (NP (DT the) (NNS lungs)))))
(, ,) (PP (IN with)(S-NOM (NP-SBJ (NP (RB even) (JJ brief) (NNS exposures)) (PP (TO to)
(NP (PRP it)))) (VP (VBG causing) (NP (NP (NNS symptoms)) (SBAR (WHNP-1 (WDT that))
(S (NP-SBJ (-NONE- *T*-1)) (VP (VBP show) (PRT (RP up)) (ADVP-TMP (NP (NNS decades))
(JJ later))))))))))) (, ,) (NP-SBJ (NNS researchers)) (VP (VBD said)(SBAR (-NONE- 0)
(S (-NONE- *T*-2)))) (. .)))
这是我的代码,但它不起作用。
import re
import nltk
from nltk.tree import *
tree = Tree.fromstring(line) // Each parse tree is stored in one single line
for subtree in tree.subtrees():
re.sub('-.*', '', subtree.label())
print tree
编辑:
我想这个问题是subtree.label()显示的节点,但它不能被改变,因为它是一个函数。打印subtree.label的输出()是:
S
S-TPC-2
NP-SBJ
NP
DT
NN
,
等等...
答
我想出了这一点:
for subtree in tree.subtrees():
s = subtree.label()
subtree.set_label(re.sub('-.*', "", s))
答
你可以做这样的事情:
for subtree in tree.subtrees():
first = subtree.label().split('-')[0]
subtree.set_label(first)