CSS 代码使用 rvest 出现在 html_nodes() 输出中答案

【问题标题】：CSS code appears in html_nodes() output using rvestCSS 代码使用 rvest 出现在 html_nodes() 输出中
【发布时间】：2022-10-13 01:53:54
【问题描述】：

作为一个小爱好项目，我正在使用 rvest 从网站上抓取一些信息。但是，对于我尝试提取的一个特定节点，它似乎将 CSS 样式代码附加到开头。

URL <- 'https://www.thepioneerwoman.com/food-cooking/recipes/a41138141/apple-pie-cookies-recipe/'
recipe <- rvest::read_html(URL)
directions <- rvest::html_nodes(recipe, ".et3p2gv0") %>%
    rvest::html_text() %>%
    trimws()

这是输出中出现的内容：

[1] ".css-dt22uw{display:none;visibility:hidden;}Step .css-6ds1rq{border-right:thin solid #b20039;height:1rem;left:-3rem;position:absolute;top:0.45rem;width:1.4rem;}1.css-1baulvz{display:inline-block;}Melt the butter in a medium saucepan over medium-high heat. Add the apples and cook until they start to soften, 3 to 4 minutes. Stir in the brown sugar and lemon juice, bring to a simmer and cook until the apples are soft and the liquid is starting to reduce, 3 to 4 more minutes. Whisk the apple juice and cornstarch in a small bowl and add it to the pan. Cook, stirring, until the mixture thickens, about 1 more minute. Remove from the heat and let cool. "

我尝试了各种不同的节点，并使用了不同的 CSS 选择器，但无论如何，它仍然出现在输出中。

我可能最终只使用 gsub() 从字符串中删除它，但宁愿不这样做。

【问题讨论】：

标签： html r rvest

【解决方案1】：

也许xml2::xml_remove() 可能会有所帮助。

URL <- 'https://www.thepioneerwoman.com/food-cooking/recipes/a41138141/apple-pie-cookies-recipe/'
recipe <- rvest::read_html(URL)
directions <- rvest::html_nodes(recipe, ".et3p2gv0")

toremove <- directions %>%
  rvest::html_node("style")

xml2::xml_remove(toremove)

directions %>%
  rvest::html_text(trim = T)

【讨论】：

【解决方案2】：

XPath text() 有时非常方便，您可以将它与 css 选择器混合匹配或将选择器重写为 XPath：

URL <- 'https://www.thepioneerwoman.com/food-cooking/recipes/a41138141/apple-pie-cookies-recipe/'
recipe <- rvest::read_html(URL)

# get a list of <li> elements with css selector and extract text from each elemnet with XPath
directions_1 <- rvest::html_elements(recipe, "ol.et3p2gv0 li") %>%
  html_nodes(xpath="./text()") %>% 
  rvest::html_text() %>%
  trimws()

# or use only XPath
directions_2 <- rvest::html_elements(recipe, xpath='//ol[contains(@class, "et3p2gv0")]/li/text()') %>%
  rvest::html_text() %>%
  trimws()

【讨论】：