R - 使用 stringr::str_split 合并两个列表中的唯一值

Question

我有一个函数，当给定一个字符串列表时，应该返回一个由 N 大小的所有唯一字符串组成的向量。

get_unique <- function (input_list, size = 3) {
   output = c()

   for (input in input_list) {
    current = stringr::str_replace(input, "[-_\\s]", "")
    current = trimws(gsub(paste0("(.{",size,"})"), "\\1 ", current))
    parts = stringr::str_split(current, "\\s", simplify = TRUE)[1,]
    output = union(output, parts)
   }

   return(output)
}

我的期望是:

get_unique(c("ABC", "ABCDEF", "GHIDEF"))

[1] "ABC" "DEF" "GHI"

但是我得到的是:

get_unique(c("ABC", "ABCDEF", "GHIDEF"))

[[1]]
[1] "ABC"

[[2]]
[1] "DEF"

[[3]]
[1] "GHI"

我对 R 还很陌生，所以我很难理解我哪里出了问题。

Answer 1

我们可以在最后使用unlist

get_unique <- function (input_list, size = 3) {
  output = c()

  for (input in input_list) {
     current = stringr::str_replace(input, "[-_\\s]", "")
     current = trimws(gsub(paste0("(.{",size,"})"), "\\1 ", current))
    parts = stringr::str_split(current, "\\s", simplify = TRUE)[1,]
    output = union(output, parts)
  }

  return(unlist(output))
 }

get_unique(c("ABC", "ABCDEF", "GHIDEF"))
#[1] "ABC" "DEF" "GHI"

---

我们还可以在单​​行中使用正则表达式环视来完成此操作，以每 3 个字符进行分割

unique(unlist(strsplit(v1, "(?<=...)", perl = TRUE)))
#[1] "ABC" "DEF" "GHI"

数据

v1 <- c("ABC", "ABCDEF", "GHIDEF")