Question

作为项目的一部分，我正在尝试从Google +中删除完整的评论（在之前的其他网站上，我的评论被More截断，除非您点击它，否则会隐藏完整评论）

我为此选择了rvest包。但是，我似乎没有得到我想要的结果。

以下是我的步骤

library(rvest)
library(xml2)
library(RSelenium)

queens <- read_html("https://www.google.co.uk/search?q=queen%27s+hospital+romford&oq=queen%27s+hospitql+&aqs=chrome.1.69i57j0l5.5843j0j4&sourceid=chrome&ie=UTF-8#lrd=0x47d8a4ce4aaaba81:0xf1185c71ae14d00,1,,,")

#Here I use the selectorgadget tool to identify the user review part that I wish to scrape

reviews=queens %>%
html_nodes(".review-snippet") %>%
html_text()

然而，这似乎不起作用。我这里没有任何输出。

我对这个包和网页抓取很新，所以对此的任何输入都将非常感激。

Answer 1

以下是RSelenium和rvest的工作流程：
1.任何时候向下滚动以获得任意数量的内容，记得暂停一下，让内容加载 2.点击全部＆＃34;点击更多＆＃34;按钮并获得完整的评论 3.获取pagesource并使用rvest将所有的启示列入清单

你想要刮的不是静态的，所以你需要RSelenium的帮助。这应该有效：

library(rvest)
library(xml2)
library(RSelenium)

rmDr=rsDriver(browser=c("chrome"), chromever="73.0.3683.68")
myclient= rmDr$client
myclient$navigate("https://www.google.co.uk/search?q=queen%27s+hospital+romford&oq=queen%27s+hospitql+&aqs=chrome.1.69i57j0l5.5843j0j4&sourceid=chrome&ie=UTF-8#lrd=0x47d8a4ce4aaaba81:0xf1185c71ae14d00,1,,,")
#click on the snippet to switch focus----------
webEle <- myclient$findElement(using = "css",value = ".review-snippet")
webEle$clickElement()
#simulate scroll down for several times-------------
scroll_down_times=20
for(i in 1 :scroll_down_times){
    webEle$sendKeysToActiveElement(sendKeys = list(key="page_down"))
    #the content needs time to load,wait 1 second every 5 scroll downs
    if(i%%5==0){
        Sys.sleep(1)
    }
}
#loop and simulate clicking on all "click on more" elements-------------
webEles <- myclient$findElements(using = "css",value = ".review-more-link")
for(webEle in webEles){
    tryCatch(webEle$clickElement(),error=function(e){print(e)}) # trycatch to prevent any error from stopping the loop
}
pagesource= myclient$getPageSource()[[1]]
#this should get you the full review, including translation and original text-------------
reviews=read_html(pagesource) %>%
    html_nodes(".review-full-text") %>%
    html_text()

#number of stars
stars <- read_html(pagesource) %>%
    html_node(".review-dialog-list") %>%
    html_nodes("g-review-stars > span") %>%
    html_attr("aria-label")


#time posted
post_time <- read_html(pagesource) %>%
    html_node(".review-dialog-list") %>%
    html_nodes(".dehysf") %>%
    html_text()

R - 使用rvest刮取Google +评论

1 个答案: