20 Jan 2014

Get No. of Google Search Hits with R and XML

UPDATE: Thanks to Max Ghenis for updating my R-script which I wrote a while back - the below R-script can now be used again for pulling the number of hits from Google-Search.

GoogleHits <- function(input)
   {
    require(XML)
    require(RCurl)
    url <- paste("https://www.google.com/search?q=\"",
                 input, "\"", sep = "")
 
    CAINFO = paste(system.file(package="RCurl"), "/CurlSSL/ca-bundle.crt", sep = "")
    script <- getURL(url, followlocation = TRUE, cainfo = CAINFO)
    doc <- htmlParse(script)
    res <- xpathSApply(doc, '//*/div[@id="resultStats"]', xmlValue)
    cat(paste("\nYour Search URL:\n", url, "\n", sep = ""))
    cat("\nNo. of Hits:\n")
    return(as.integer(gsub("[^0-9]", "", res)))
   }
 
# Example:
GoogleHits("R%Statistical%Software")
p.s.: If you try to do this in a robot fashion, like:
lapply(list_of_search_terms, GoogleHits)
google will block you after about the 300th recursion!

7 comments :

  1. great script! any way to get around the block of google after the 300th recursion?

    ReplyDelete
  2. I guess there are some changes with google output.
    To make it working I had to remove [[2]] from the following command.
    res <- xpathSApply(doc, "//div[@id='subform_ctrl']/*", xmlValue)[[2]]

    ReplyDelete
  3. Google output changed again, need to change the path to '//*/div[@id="resultStats"]'

    ReplyDelete
  4. Also I don't believe stringr is needed

    ReplyDelete
    Replies
    1. of course (just forgot to remove the line..)

      Delete