How can I turn the filename into a variable when reading multiple csvs into R

Question

I have a bunch of csv files that follow the naming scheme: est2009US.csv.

I am reading them into R as follows:

myFiles <- list.files(path=\"~/Dow         


        

Answer 1

You can avoid looping twice by using an anonymous function that assigns the file name as a column to each data.frame in the same lapply that you use to read the csvs.

myDB <- do.call("rbind", lapply(myFiles, function(x) {
  dat <- read.csv(x, header=TRUE)
  dat$fileName <- tools::file_path_sans_ext(basename(x))
  dat
}))

I stripped out the directory and file extension. basename() returns the file name, not including the directory, and tools::file_path_sans_ext() removes the file extension.