在一列中搜索多个关键字并为每个关键字创建列

这是基本的 R 单行代码。使用将单词边界锚点sprintf()添加到每个模式。这意味着，例如，不会匹配。然后使用 迭代这些模式，使用将每个模式与 匹配。这将返回一个逻辑向量列表，我们可以将其分配回数据框。\\b "and""random"lapply()grepl()datatxt$x

datatxt[stringstosearch] <- lapply(
    sprintf("\\b%s\\b", stringstosearch), \(x) grepl(x, datatxt$x)
)

现在datatxt如愿了：

          id                                                                  x    to   and    at  from    is    of
1 -1.9091427 Contrary to popular belief, Lorem Ipsum is not simply random text.  TRUE FALSE FALSE FALSE  TRUE FALSE
2  0.5551667            A Latin professor at Hampden-Sydney College in Virginia FALSE FALSE  TRUE FALSE FALSE FALSE
3 -2.2163365                        It has roots in a piece of classical Latin  FALSE FALSE FALSE FALSE FALSE  TRUE
4  0.4941455              literature from 45 BC, making it over 2000 years old. FALSE FALSE FALSE  TRUE FALSE FALSE
5 -0.5805710                       The standard chunk of Lorem Ipsum used since FALSE FALSE FALSE FALSE FALSE  TRUE

tidyverse方法

正如您所标记的tidyverse，这里有一个替代方法。这将返回与使用函数的基本 R 方法相同的列表tidyverse，只是它有名称。然后我们可以使用拼接运算符将其dplyr::mutate()作为新列传递给：

datatxt |>
    dplyr::mutate(
        !!!purrr::map(
            purrr::set_names(
                stringr::str_glue("\\b{stringstosearch}\\b"),
                stringstosearch
            ),
            \(str) stringr::str_detect(x, str)
        )
    )
# ^^ same output

我认为基础 R 方法更加清晰。

我建议Vectoriz[e]使用pattern以下论点stringfish::sf_grepl()：

Vsf_grepl = Vectorize(\(pattern) stringfish::sf_grepl(datatxt$x, pattern))
datatxt[stringstosearch] = Vsf_grepl(sprintf("\\b%s\\b", stringstosearch))

给出

> datatxt
  id                                                                  x    to   and    at  from    is    of
1  1 Contrary to popular belief, Lorem Ipsum is not simply random text.  TRUE FALSE FALSE FALSE  TRUE FALSE
2  2            A Latin professor at Hampden-Sydney College in Virginia FALSE FALSE  TRUE FALSE FALSE FALSE
3  3                        It has roots in a piece of classical Latin  FALSE FALSE FALSE FALSE FALSE  TRUE
4  4              literature from 45 BC, making it over 2000 years old. FALSE FALSE FALSE  TRUE FALSE FALSE
5  5                       The standard chunk of Lorem Ipsum used since FALSE FALSE FALSE FALSE FALSE  TRUE

注意，我将id世代改为id = 1:5。

我有一个（不同的）tidyverse解决方案：

library(tidyverse)

stringstosearch <- c("to", "and", "at", "from", "is", "of")
strings <- c(
  "Contrary to popular belief, Lorem Ipsum is not simply random text.",
  "A Latin professor at Hampden-Sydney College in Virginia",
  "It has roots in a piece of classical Latin ",
  "literature from 45 BC, making it over 2000 years old.",
  "The standard chunk of Lorem Ipsum used since"
)

datatxt <- tibble(
  id = seq_along(strings),
  x = strings,
  !!!stringstosearch %>% set_names()
) %>%
  mutate(
    across(
      all_of(stringstosearch),
      ~ grepl(paste0("\\b",cur_column(),"\\b"), x, ignore.case = TRUE)
    )
  )

此代码首先创建数据框，使用!!!运算符 from为stringstosearchtidyverse向量中的每个元素创建一列。如果没有该函数，列名将被引号引起来。然后，我们遍历由stringstosearch元素确定的所有列。对于每一列，我们确定在调用 through 时检索到的列名是否存在于x列中，并在正则表达式中添加“\\b”以确定单词边界并防止误报（正如 SamR 指出的那样）。set_names()mutate()grepl()cur_column()

现在datatxt输出：

# A tibble: 5 × 8
     id x                                                                    to    and   at    from  is    of   
  <int> <chr>                                                                <lgl> <lgl> <lgl> <lgl> <lgl> <lgl>
1     1 "Contrary to popular belief, Lorem Ipsum is not simply random text." TRUE  FALSE FALSE FALSE TRUE  FALSE
2     2 "A Latin professor at Hampden-Sydney College in Virginia"            FALSE FALSE TRUE  FALSE FALSE FALSE
3     3 "It has roots in a piece of classical Latin "                        FALSE FALSE FALSE FALSE FALSE TRUE 
4     4 "literature from 45 BC, making it over 2000 years old."              FALSE FALSE FALSE TRUE  FALSE FALSE
5     5 "The standard chunk of Lorem Ipsum used since"                       FALSE FALSE FALSE FALSE FALSE TRUE 

library(tidyverse)

stringstosearch <- c("to", "and", "at", "from", "is", "of") %>% 
  set_names()

set.seed(199)

datatxt <- data.frame(id = c(rnorm(5)), 
                      x = c("Contrary to popular belief, Lorem Ipsum is not simply random text.",
                            "A Latin professor at Hampden-Sydney College in Virginia",
                            "It has roots in a piece of classical Latin ", 
                            "literature from 45 BC, making it over 2000 years old.", 
                            "The standard chunk of Lorem Ipsum used since"))

bind_cols(datatxt, imap(
  .x = stringstosearch,
  .f = ~ transmute(datatxt,!!.y := str_detect(x, glue::glue("\\b{.x}\\b")))
))
#>           id                                                                  x
#> 1 -1.9091427 Contrary to popular belief, Lorem Ipsum is not simply random text.
#> 2  0.5551667            A Latin professor at Hampden-Sydney College in Virginia
#> 3 -2.2163365                        It has roots in a piece of classical Latin 
#> 4  0.4941455              literature from 45 BC, making it over 2000 years old.
#> 5 -0.5805710                       The standard chunk of Lorem Ipsum used since
#>      to   and    at  from    is    of
#> 1  TRUE  TRUE FALSE FALSE  TRUE FALSE
#> 2 FALSE FALSE  TRUE FALSE FALSE  TRUE
#> 3 FALSE FALSE  TRUE FALSE FALSE  TRUE
#> 4 FALSE FALSE  TRUE  TRUE FALSE FALSE
#> 5 FALSE  TRUE FALSE FALSE FALSE  TRUE

^{创建于 2024-11-13，使用reprex v2.0.2}