Importing multiple .csv files into R and adding a new column with file name

Question

I have 80 separate .csv files that have the same columns and headers that I was able to import and rbind as one dataframe using the following commands:

 file_names <- dir("~/Desktop/data") 
 df <- do.call(rbind,lapply(file_names,read.csv))

But I would like to add a new variable ("name") that identifies from which .csv file each observation came from. So for example, this variable "name" would be "NY" for all the observations from the 'NY.csv' file and "DC" for all observations from the 'DC.csv' file, etc... Is there any way to do this without adding this new column manually on each .csv? Thanks!

Answer 1

This should do it:

file_names <- dir("~/Desktop/data") 
df <- do.call(rbind, lapply(file_names, function(x) cbind(read.csv(x), name=strsplit(x,'\\.')[[1]][1])))