How to import multiple .csv files at once?

Question

Suppose we have a folder containing multiple data.csv files, each containing the same number of variables but each from different times.Is there a way in R to import them all simultaneously rather than having to import them all individually?My problem is that I have around 2000 data files to import and having to import them individually just by using the code: read.delim(file="filename", header=TRUE, sep="\ ")is not very efficient.

Answer 1

Suppose you have a directory in a path /Users/home/dir1

And suppose you have multiple csv files within the directory.

A simple way to achieve your goal is to use function list.files and looping over reading file command.

Here is my R code example, hope this helps!

## set path

DIR_path="/Users/home/dir1/"

## retrieve file names

ls_filenames<-list.files(path=DIR_path,pattern=".csv$")

## $ is general expression for telling end of the string.

## now you have list of filenames with .csv extension in your folder

## you could start read files now

## I'm going to use R list object to do this

df.current<-list() # first create a blank list object

# then write a loop

for (i in 1:length(ls_filenames)){

df.current[[i]]<-read.csv(paste0(DIR_path,ls_filenames[i]))

## read each file from the path

}

## this loop will assign each data to corresponding list element.

names(df.current)=ls_filenames

## assign name of each list element with source filenames

Now you could call the data from the list by using original file names, such as: df.current$filename1.csv