Question

以this question为基础，我希望从smallText节点中提取单个节点（“喜欢”），但忽略其他节点。我要查找的节点是a.SmallText，因此只需选择一个即可。

代码：

url <- "https://www.goodreads.com/quotes/search?page=1&q=simone+de+beauvoir&utf8=%E2%9C%93"

quote_rating <- function(html){

  path <- read_html(html)

  path %>% 
    html_nodes(xpath = paste(selectr::css_to_xpath(".smallText"), "/text()"))%>%
    html_text(trim = TRUE) %>% 
    str_trim(side = "both") %>% 
    enframe(name = NULL)
}

quote_rating(url)

给出的结果：

# A tibble: 80 x 1
   value              
   <chr>              
 1 Showing 1-20 of 790
 2 (0.03 seconds)     
 3 tags:              
 4 ""                 
 5 2492 likes         
 6 2265 likes         
 7 tags:              
 8 ,                  
 9 ,                  
10 ,                  
# ... with 70 more rows

添加过多的html_nodes("a.smallText")过滤器：

quote_rating <- function(html){

  path <- read_html(html) 

  path %>% 
    html_nodes(xpath = paste(selectr::css_to_xpath(".smallText"), "/text()")) %>%
    html_nodes("a.smallText") %>% 
    html_text(trim = TRUE) %>%
    str_trim(side = "both") %>% 
    enframe(name = NULL)

}

# A tibble: 0 x 1
# ... with 1 variable: value <chr>
>

Answer 1

这对我有用...

library(rvest)
url <- "https://www.goodreads.com/quotes/search?page=1&q=simone+de+beauvoir&utf8=%E2%9C%93"
page <- read_html(url)
page %>% html_nodes("div.quote.mediumText") %>%   #select quote boxes
  html_node("a.smallText") %>%                    #then the smallText in each one
  html_text()

 [1] "2492 likes" "2265 likes" "2168 likes"
 [4] "2003 likes" "1774 likes" "1060 likes"
 [7] "580 likes"  "523 likes"  "482 likes" 
[10] "403 likes"  "383 likes"  "372 likes" 
[13] "360 likes"  "347 likes"  "330 likes" 
[16] "329 likes"  "318 likes"  "317 likes" 
[19] "310 likes"  "281 likes"

请注意html_node和html_nodes之间的区别。首先选择引号框的好处是，您可以根据需要提取其他信息，然后轻松将其与“喜欢”数进行匹配。

Answer 2

提取每个报价的点赞次数。一个人可以只使用css选择器来执行过滤，一个人想要使用a查找class=smallText标签。

此简单的代码片段有效：

library(rvest)
url <- "https://www.goodreads.com/quotes/search?page=1&q=simone+de+beauvoir&utf8=%E2%9C%93"

path <- read_html(url) 

path %>% 
    html_nodes("a.smallText") %>% 
    html_text(trim = TRUE)

# [1] "2492 likes" "2265 likes" "2168 likes" "2003 likes" "1774 likes" "1060 likes" "580 likes" 
# [8] "523 likes"  "482 likes"  "403 likes"  "383 likes"  "372 likes"  "360 likes"  "347 likes" 
# [15] "330 likes"  "329 likes"  "318 likes"  "317 likes"  "310 likes"  "281 likes"

刮除单个节点，排除相同类别的其他节点

2 个答案: