获取慕课网所有课程, 测试通过 download<-function(Url) { dat<-data.frame() while(nchar(Url)!=20) { web<-read_html(Url) title<-web%>%html_nodes('div.course-card-content h3')%>%html_text() info<-web%>%html_nodes('div.course-card-info span')%>%html_text() rank<-info[seq(1,length(info),2)] num<-info[seq(2,length(info),2)] dat<-rbind(dat,data.frame(title,rank,num)) # print(data.frame(title,rank,num)) page.link<-web%>% html_nodes('div.page a') Url<-paste0(s,page.link[grep(pattern = "下一页",page.link)]%>%html_attr(name = 'href')) } return(dat) }