R - 如何从 XML 节点集中提取项目？

Question

我有一个包含 438 个投手名称的列表，看起来像这样（在 XML 节点集中）：

> pitcherlinks[[1]]
<td class="left " data-append-csv="abadfe01" data-stat="player" csk="Abad,Fernando0.01">
  <a href="/players/a/abadfe01.shtml">Fernando Abad</a>*
</td> 

> pitcherlinks[[2]]
<td class="left " data-append-csv="adlemti01" data-stat="player" csk="Adleman,Tim0.01">
  <a href="/players/a/adlemti01.shtml">Tim Adleman</a>
</td> 

如何提取Fernando Abad 之类的名称以及/players/a/abadfe01.shtml 之类的关联链接

Answer 1

由于您有一个列表，因此可以使用一个 apply 函数来遍历该列表。每个函数使用read_html 解析列表中的hmtl 片段，使用CSS 选择器a 来查找锚点（链接）。名称来自html_text，链接在属性href中

library(rvest)
pitcherlinks <- list()
pitcherlinks[[1]] <- 
'<td class="left " data-append-csv="abadfe01" data-stat="player" csk="Abad,Fernando0.01">
  <a href="/players/a/abadfe01.shtml">Fernando Abad</a>*
    </td>'

pitcherlinks[[2]] <- 
  '<td class="left " data-append-csv="adlemti01" data-stat="player" csk="Adleman,Tim0.01">
    <a href="/players/a/adlemti01.shtml">Tim Adleman</a>
      </td>'

names <- sapply(pitcherlinks, function(x) {x %>% read_html() %>% html_nodes("a") %>% html_text()})
links <- sapply(pitcherlinks, function(x) {x %>% read_html() %>% html_nodes("a") %>% html_attr("href")})

names
# [1] "Fernando Abad" "Tim Adleman"  
links
# [1] "/players/a/abadfe01.shtml"  "/players/a/adlemti01.shtml"