如何导入 XML-LMF 格式的词典以在 R 中进行情感分析

How to import a lexicon in XML-LMF format for sentiment analysis in R

我正在尝试在 R 中导入以下词典,以便与 quanteda 等文本挖掘包一起使用,或者将其导出为列表或数据框:

https://github.com/opener-project/VU-sentiment-lexicon/tree/master/VUSentimentLexicon/IT-lexicon

格式为XML-LMF。我找不到任何方法来用 R 解析这种格式。

(参见 https://en.wikipedia.org/wiki/Lexical_Markup_Framework

作为解决方法,我尝试使用 XML 包,但结构与通常的 XML 有点不同,而且我没有设法解析所有节点。

我设法使用 xml2 包让它工作。这是我的代码:

library(xml2)
library(quanteda)

# Read file and find the nodes
opeNER_xml <- read_xml("it-sentiment_lexicon.lmf.xml")
entries <- xml_find_all(opeNER_xml, ".//LexicalEntry")
lemmas <- xml_find_all(opeNER_xml, ".//Lemma")
confidence <- xml_find_all(opeNER_xml, ".//Confidence")
sentiment <- xml_find_all(opeNER_xml, ".//Sentiment")

# Parse and put in a data frame
opeNER_df <- data.frame(
  id = xml_attr(entries, "id"),
  lemma = xml_attr(lemmas, "writtenForm"),
  partOfSpeech = xml_attr(entries, "partOfSpeech"),
  confidenceScore = as.numeric(xml_attr(confidence, "score")),
  method = xml_attr(confidence, "method"),
  polarity = as.character(xml_attr(sentiment, "polarity")),
  stringsAsFactors = F
)
# Fix a mistake
opeNER_df$polarity <- ifelse(opeNER_df$polarity == "nneutral", 
                             "neutral", opeNER_df$polarity)

# Make quanteda dictionary
opeNER_dict <- quanteda::dictionary(with(opeNER_df, split(lemma, polarity)))