如何从单词列表中提取第一个单词？

Question

我无法从单词列表中提取第一个单词。我试过 substring、gsub 和 str_extract，但还是没弄明白。请指教。谢谢你。这是我正在尝试做的事情：

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

我正在尝试从如下所示的列表中提取第一个单词：

Extracted
print
take
score

Answer 1

单独使用基础 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])

Answer 2

您可以只使用 purrr::map 和索引参数，如下所示：

如果您希望输出以列表形式返回：

  > 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"

如何从单词列表中提取第一个单词？

How do I extract the first word from a list of words?

r

text-mining