如何从单词列表中提取第一个单词?

时间:2019-01-24 17:05:34

标签: r text-mining

我在从单词列表中提取第一个单词时遇到麻烦。我试过子字符串,gsub和str_extract,但仍然没有弄清楚。请指教。谢谢。这是我想要做的:

Word
"c("print", "printing", "prints")"
"c("take", "takes", "taking")"
"c("score", "scoring", "scored")"

我正在尝试从列表中提取第一个单词,如下所示:

Extracted
print
take
score

2 个答案:

答案 0 :(得分:1)

您可以仅将purrr::map与索引参数一起使用,如下所示:

如果您希望将输出作为列表返回:

  > purrr::map(Word, 1)
  # [[1]]
  # [1] "print"
  #
  # [[2]]
  # [1] "take"
  #
  # [[3]]
  # [1] "score"

如果您希望它作为向量返回:

  > purrr::map_chr(Word, 1)
  # [1] "print" "take"  "score"

答案 1 :(得分:0)

仅使用基数R

##Just to recreate the data
df <- tibble(
  Word= list(c("print", "printing", "prints"),c("take", "takes", "taking"),c("score", "scoring", "scored")))

###
df$Extracted <- sapply(1:length(df$Word), function(i)df$Word[[i]][1])