对齐单词以形成带括号的字符串

Question

假设，我有以下带标点符号的括号字符串：

s = "(S (NP-SBJ (NP (NP (NNP Ambassador) (NNP Paul) (NNP Nitze) (POS 's)) (NN statement)) (PRN (-LRB- -LRB-) (NP (NP-TTL (NNP Notable) (CC &) (NNP Quotable)) (, ,) (NP-TMP (NNP Sept.) (CD 20))) (-RRB- -RRB-) (, ,) (`` ``)) (S (SBAR-ADV (IN If) (S (NP-SBJ (PRP you)) (VP (VBP have) (NP (NP (DT a) (CD million) (NNS people)) (VP (VBG working) (PP (IN for) (NP (PRP you)))))))) (, ,) (NP-SBJ (NP (DT every) (JJ bad) (NN thing)) (SBAR (WHNP-1 (WDT that)) (S (VP (VBZ has) (NP (NP (CD one) (NN chance)) (PP (IN in) (NP (DT a) (CD million))) (PP (IN of) (S-NOM (VP (VBG going) (ADVP-CLR (NN wrong)))))))))) (VP (MD will) (VP (VB go) (ADVP-CLR (JJ wrong)) (ADVP-TMP (ADVP (IN at) (JJS least)) (IN once) (NP-ADV (DT a) (NN year)))))) (, ,) ('' '')) (VP (VBZ is) (NP-PRD (NP (DT a) (ADJP (RB pretty) (JJ negative)) (NN way)) (PP (IN of) (S-NOM (VP (VBG looking) (PP-CLR (IN at) (NP (NNS things)))))))) (. .))"

还有，我需要删除的标点参考列表：

punctuation_words = ['.', ',', ':', '-LRB-', '-RRB-', '\'\'', '``', '--', ';',
                     '-', '?', '!', '...', '-LCB-', '-RCB-']
currency_tags_words = ['#', '$', 'C$', 'A$', 'US$']
filterwords = punctuation_words + currency_tags_words

我想得到如下输出：

out = "(S (NP-SBJ (NP (NP (NNP Ambassador) (NNP Paul) (NNP Nitze) (POS 's)) (NN statement)) (PRN (NP (NP-TTL (NNP Notable) (CC &) (NNP Quotable)) (NP-TMP (NNP Sept.) (CD 20)))) (S (SBAR-ADV (IN If) (S (NP-SBJ (PRP you)) (VP (VBP have) (NP (NP (DT a) (CD million) (NNS people)) (VP (VBG working) (PP (IN for) (NP (PRP you)))))))) (NP-SBJ (NP (DT every) (JJ bad) (NN thing)) (SBAR (WHNP-1 (WDT that)) (S (VP (VBZ has) (NP (NP (CD one) (NN chance)) (PP (IN in) (NP (DT a) (CD million))) (PP (IN of) (S-NOM (VP (VBG going) (ADVP-CLR (NN wrong)))))))))) (VP (MD will) (VP (VB go) (ADVP-CLR (JJ wrong)) (ADVP-TMP (ADVP (IN at) (JJS least)) (IN once) (NP-ADV (DT a) (NN year))))))) (VP (VBZ is) (NP-PRD (NP (DT a) (ADJP (RB pretty) (JJ negative)) (NN way)) (PP (IN of) (S-NOM (VP (VBG looking) (PP-CLR (IN at) (NP (NNS things)))))))))"

到目前为止，这是我尝试过的：

import nltk

t = nltk.Tree.fromstring(s)
sent = " ".join(item[0] for item in t.pos())
sent_without_punct = " ".join([item for item in sent.split() if item not in filterwords])
print(sent_without_punct)
# "Ambassador Paul Nitze 's statement Notable & Quotable Sept. 20 If you have a million people working for you every bad thing that has one chance in a million of going wrong will go wrong at least once a year is a pretty negative way of looking at things"

这给了我没有标点符号的正确输出。但我很难将其合并回来以获取类似于out 的括号字符串。

编辑： POS 标签在这里不相关。因此，如果有帮助，我们可以将其替换为开始符号“S”，如下所示：

"(S (S (S (S (S Ambassador) (S Paul) (S Nitze) (S 's)) (S statement)) (S (S -LRB-) (S (S (S Notable) (S &) (S Quotable)) (S ,) .... "

Answer 1

您想删除像(A - A) 这样的模式，其中( 旁边的文本及其匹配的) 是相同的并且来自您的过滤字符串。

你可以使用

import re
punctuation_words = ['.', ',', ':', '-LRB-', '-RRB-', '\'\'', '``', '--', ';',
                     '-', '?', '!', '...', '-LCB-', '-RCB-']
currency_tags_words = ['#', '$', 'C$', 'A$', 'US$']
filterwords = punctuation_words + currency_tags_words
filter_rx = "|".join(sorted(map(re.escape,filterwords), key=len, reverse=True))
rx = r"\s*\(({0}) \1\)".format(filter_rx)
text = "(S (NP-SBJ (NP (NP (NNP Ambassador) (NNP Paul) (NNP Nitze) (POS 's)) (NN statement)) (PRN (-LRB- -LRB-) (NP (NP-TTL (NNP Notable) (CC &) (NNP Quotable)) (, ,) (NP-TMP (NNP Sept.) (CD 20))) (-RRB- -RRB-) (, ,) (`` ``)) (S (SBAR-ADV (IN If) (S (NP-SBJ (PRP you)) (VP (VBP have) (NP (NP (DT a) (CD million) (NNS people)) (VP (VBG working) (PP (IN for) (NP (PRP you)))))))) (, ,) (NP-SBJ (NP (DT every) (JJ bad) (NN thing)) (SBAR (WHNP-1 (WDT that)) (S (VP (VBZ has) (NP (NP (CD one) (NN chance)) (PP (IN in) (NP (DT a) (CD million))) (PP (IN of) (S-NOM (VP (VBG going) (ADVP-CLR (NN wrong)))))))))) (VP (MD will) (VP (VB go) (ADVP-CLR (JJ wrong)) (ADVP-TMP (ADVP (IN at) (JJS least)) (IN once) (NP-ADV (DT a) (NN year)))))) (, ,) ('' '')) (VP (VBZ is) (NP-PRD (NP (DT a) (ADJP (RB pretty) (JJ negative)) (NN way)) (PP (IN of) (S-NOM (VP (VBG looking) (PP-CLR (IN at) (NP (NNS things)))))))) (. .))"
print( re.sub(rx, "", text) )

请参阅Python demo 和regex demo。

正则表达式是\s*\(<PATTERN> \1\) 类型，并且匹配

• \s* - 零个或多个空格
• \( - 一个 ( 字符
• (\-LRB\-|\-RRB\-|\-LCB\-|\-RCB\-|\.\.\.|\-\-|US\$|C\$|A\$|\.|''|``|\-|\?|\#|\$|,|:|;|!) - 过滤器之一
• - 空格
• \1 - 组 1 反向引用匹配与组 1 中捕获的相同文本
• \) - 一个 ) 字符。