R语言：处理无HTML标签字符串的read_html()+html_text()替代方案

在使用rvest移除字符串HTML标签时，常规做法是用rvest::read_html()生成html_document对象，再通过rvest::html_text()提取纯文本。但当字符串不含HTML标签时，read_html()会误将其识别为文件路径，导致批量处理报错。示例代码如下：

library(rvest)

# Example data
dat <- c(
  "<B>Positives:</B> Rangy, athletic build with room for additional growth. ...",
  "Positives: Better football player than his measureables would indicate. ..."
)

# Success: produces html_document object
rvest::read_html(dat[1])
#> {html_document}
#> <html>
#> [1] <body>
<b>Positives:</b> Rangy, athletic build with room for additional  ...

# Error
rvest::read_html(dat[2])
#> Error in `path_to_connection()`:
#> ! 'Positives: Better football player than his measureables would
#>   indicate. ...' does not exist in current working directory
#>   ('C:/LONG_PATH_HERE').

可行解决方案 #

• 强制将字符串视为HTML内容传入：
  read_html()底层依赖xml2::read_html()，通过将字符串包装成I()（AsIs对象），可强制函数把输入当作HTML内容而非文件路径，无需额外计算。示例：

  library(rvest)
  
  safe_extract_text <- function(x) {
    html_text(read_html(I(x)))
  }
  
  # 批量处理测试
  sapply(dat, safe_extract_text)
  

• 备选：轻量标签包装（兼容旧版本）：
  若上述方法因版本问题失效，可给字符串包裹极简HTML标签（如<div>），计算开销极小且兼容性强：

  safe_extract_text <- function(x) {
    html_text(read_html(paste0("<div>", x, "</div>")))
  }
  

内容的提问来源于stack exchange，提问作者socialscientist