Humphrey Zhao
2015-Jun-16 13:01 UTC
[R] Question about XML package (accurately access one attribute in an multi-attribution node on the web page)
Dear?Sir/Madam: Thank?you for your attention to my question.?I?have downloaded?the source code of some web?pages?by?RCurl,?and?I?am?trying?to?extract?the?URL?from?them.?In?these?web?pages,?there?are?many?nodes?contains?the?same?URL,?such?like?the?followings: <a?href=\"http://cos.name/2015/05/the-data-wisdom-for-data-science/\"?rel=\"bookmark\"> <a?href=\"http://blog.shakirm.com/2015/03/a-statistical-view-of-deep-learning-ii-auto-encoders-and-free-energy/\"?target=\"_blank\"> <a?href=\"http://cos.name/2015/05/the-data-wisdom-for-data-science/#more-10947\"?class=\"more-link\"> I?want?to?accurately?choose?the?URL?I?need(the "href"?in the?first?one),?and?I?tried?many?ways?the?most?accuracy?is?just?like?the?following: library(XML) #links<-getHTMLLinks(base.html,?xpQuery?=?"//a/@href") links<-getHTMLLinks(base.html,?xpQuery?=?c("//a/href[@rel='bookmark']")) However,?I?still?believe?that?there?is?a?correct?method?to?do?this?very?well,?but?I?could?not?find?it.?I?wonder?if?you?could?give?me?some?advice?on?solving?this?problem.?And?I?would?be?most?grateful?if?you?could?reply?at?your?earliest?convenience.?Looking?forward?to?hearing?from?you.?Thank?you?very?much. ?????????????????????????????????????Sincerely?yours? ?????????????????????????????????????Humphrey?Zhao [[alternative HTML version deleted]]
Boris Steipe
2015-Jun-16 17:17 UTC
[R] Question about XML package (accurately access one attribute in an multi-attribution node on the web page)
Humphrey - Any "correct" method requires you to specify _uniquely_ what you are looking for. If the bookmark keyword is necessary and unique, it appears you have a working solution. Or what else where you trying to accomplish? Cheers, Boris On Jun 16, 2015, at 9:01 AM, Humphrey Zhao <humphrey.zhao at yahoo.com> wrote:> Dear Sir/Madam: > > Thank you for your attention to my question. I have downloaded the source code of some web pages by RCurl, and I am trying to extract the URL from them. In these web pages, there are many nodes contains the same URL, such like the followings: > > <a href=\"http://cos.name/2015/05/the-data-wisdom-for-data-science/\" rel=\"bookmark\"> > > <a href=\"http://blog.shakirm.com/2015/03/a-statistical-view-of-deep-learning-ii-auto-encoders-and-free-energy/\" target=\"_blank\"> > > <a href=\"http://cos.name/2015/05/the-data-wisdom-for-data-science/#more-10947\" class=\"more-link\"> > > I want to accurately choose the URL I need(the "href" in the first one), and I tried many ways the most accuracy is just like the following: > > library(XML) > > #links<-getHTMLLinks(base.html, xpQuery = "//a/@href") > > links<-getHTMLLinks(base.html, xpQuery = c("//a/href[@rel='bookmark']")) > > However, I still believe that there is a correct method to do this very well, but I could not find it. I wonder if you could give me some advice on solving this problem. And I would be most grateful if you could reply at your earliest convenience. Looking forward to hearing from you. Thank you very much. > > Sincerely yours > > Humphrey Zhao > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.