无法识别用于在 rvest 中抓取的 html 节点

Question

试图从页面中抓取链接以进行后续分析，但只能抓取其中的 1/2，这可能是由于过滤造成的。我正在尝试提取此处突出显示的链接：

我的方法如下，这并不理想，因为我相信我可能会在filter() 调用中丢失一些链接。

library(rvest)
library(tidyverse)

#initiate session
session <- html_session("https://www.backlisted.fm/episodes")

#collect links for all episodes from the index page:

session %>% 
  read_html() %>% 
  html_nodes(".underline-body-links a") %>% 
  html_attr("href") %>% 
  tibble(link_temp = .) %>% 
  filter(str_detect(link_temp, pattern = "episodes/")) %>%
  distinct()

#css:
#.underline-body-links #page .html-block a, .underline-body-links #page .product-excerpt ahere
 
#result:

link_temp                                                                        
   <chr>                                                                            
 1 /episodes/116-mfk-fisher-how-to-cook-a-wolf                                      
 2 https://www.backlisted.fm/episodes/109-barbara-pym-excellent-women               
 3 /episodes/115-george-amp-weedon-grossmith-the-diary-of-a-nobody                  
 4 https://www.backlisted.fm/episodes/27-jane-gardam-a-long-way-from-verona         
 5 https://www.backlisted.fm/episodes/5-b-s-johnson-christie-malrys-own-double-entry
 6 https://www.backlisted.fm/episodes/97-ray-bradbury-the-illustrated-man           
 7 /episodes/114-william-golding-the-inheritors                                     
 8 https://www.backlisted.fm/episodes/30-georgette-heyer-venetia                    
 9 https://www.backlisted.fm/episodes/49-anita-brookner-look-at-me                  
10 https://www.backlisted.fm/episodes/71-jrr-tolkien-the-return-of-the-king         
# … with 43 more rows

我一直在阅读多个文档，但我无法针对那一种类型的 href。任何帮助都感激不尽。谢谢。

Answer 1

试试这个

library(rvest)
library(tidyverse)

session <- html_session("https://www.backlisted.fm/index")
raw_html <- read_html(session)
node <- raw_html %>% html_nodes(css = "li p a")
link <- node %>% html_attr("href")
title <- node %>% html_text()
tibble(title, link)

# A tibble: 117 x 2
#    title                                          link                                                                     
#    <chr>                                          <chr>                                                                    
#  1 "A Month in the Country"                       https://www.backlisted.fm/episodes/1-j-l-carr-a-month-in-the-country     
#  2 " - J.L. Carr (with Lissa Evans)"              #                                                                        
#  3 "Good Morning, Midnight - Jean Rhys"           https://www.backlisted.fm/episodes/2-jean-rhys-good-morning-midnight     
#  4 "It Had to Be You - David Nobbs"               https://www.backlisted.fm/episodes/3-david-nobbs-1                       
#  5 "The Blessing - Nancy Mitford"                 https://www.backlisted.fm/episodes/4-nancy-mitford-the-blessing          
#  6 "Christie Malry's Own Double Entry - B.S. Joh… https://www.backlisted.fm/episodes/5-b-s-johnson-christie-malrys-own-dou…
#  7 "Passing - Nella Larsen"                       https://www.backlisted.fm/episodes/6-nella-larsen-passing                
#  8 "The Great Fire - Shirley Hazzard"             https://www.backlisted.fm/episodes/7-shirley-hazzard-the-great-fire      
#  9 "Lolly Willowes - Sylvia Townsend Warner"      https://www.backlisted.fm/episodes/8-sylvia-townsend-warner-lolly-willow…
# 10 "The Information - Martin Amis"                https://www.backlisted.fm/episodes/9-martin-amis-the-information         
# … with 107 more rows