In R, how to extracting two values from XML file, looping over 5603 files and write to table

Question

As I am rather new to R, I am trying to learn how I can extract two values from a XML file and loop over 5603 other (small, <2kb) XML files in my working directory.

Answer 1

This might work for you. I got rid of the for loop and went with sapply.

xmlfiles <- list.files(pattern = "*.xml")
txtfiles <- gsub("xml", "txt", xmlfiles, fixed = TRUE)

txtfiles is a set of new file names to be used as the output file for each run.

sapply(seq(xmlfiles), function(i){

  doc <- xmlTreeParse(xmlfiles[i], useInternal = TRUE)
  zipcode <- xmlValue(doc[["//ZipCode"]])
  amount <- xmlValue(doc[["//AwardAmount"]])
  DF <- data.frame(zip = zipcode, amount = amount)
  write.table(DF, quote = FALSE, row.names = FALSE, file = txtfiles[i])

})

Please, let me know if there are issues when you run it.