1
以下代码转到R Journal的Accepted articles页面,并下载第一篇文章,其中包含包。关注多个链接rverst :: follow_link()
library(rvest)
library(magrittr)
url_stem <- html_session("https://journal.r-
project.org/archive/accepted/")
url_paper <- follow_link(url_stem, "package") %>%
follow_link("package") -> url_article
download.file(url_article$url, destfile = "article.pdf")
我想什么是下载所有具有从一组给定的话的一个或多个mathing字的文章。
由于follow_link()
需要一个表达式,因此我试图循环搜索条件 - 考虑到函数在未找到匹配链接的情况下返回错误的事实。
library(rvest)
library(magrittr)
url_stem <- html_session("https://journal.r-project.org/archive/accepted/")
search_terms <- c("package", "model", "linear")
tryCatch(
for(i in search_terms) {
url_paper <- follow_link(url_stem, search_terms[i]) %>%
follow_link(search_terms[i]) -> url_article
download.file(url_article$url, destfile = "article.pdf") # Don't how I would write it as article[i=1,2, ...].pdf
}
)
我收到以下错误:
Error in if (!any(match)) { : missing value where TRUE/FALSE needed
This线程是不是有用,因为它解决了tags
的情况。这个问题似乎很简单,可能会以更简单的方式解决,但这可能是因为R期刊网站非常整洁。有些网站相当混乱。