Importing and merging .csv files with loop in R

Question

I have 20 files named 1.csv, 2.csv, 3.csv etc, which I want to read into R and merge using rbind using a loop. I've tried the code below but I get an error message saying unexpected "[" in the second line.

for (i in 1:22) {
  fish[i]  <- read.csv([i].csv)
  combined <- rbind(fish[i], fish[i+1])
}

also if you only have 20 files, your loop should only be `1:20` I think. — Jakob Gepp, Dec 13 '18 at 14:05
for (i in 1:22) { fish[i] <- read.csv(paste0(i, ".csv")) combined <- rbind(fish[i], fish[i+1]) } — Alice, Dec 13 '18 at 14:06
yes, this is because it is not defined before the loop ans so R does not know its index. — Jakob Gepp, Dec 13 '18 at 14:09
related: https://stackoverflow.com/questions/11433432/how-to-import-multiple-csv-files-at-once — jogo, Dec 13 '18 at 14:21

score 0 · Answer 1 · answered Dec 13 '18 at 14:08

To put my comment in a answer:

# just for rbindlist, there are also base ways to do this
library(data.table)

fish <- list()
for (i in 1:20) {
  fish[[i]] <- read.csv(paste0(i, ".csv"))
}
combined <- rbindlist(fish)

Alternative: Same as do.call("rbind", fish) on data.frames, but much faster.

Importing and merging .csv files with loop in R

1 Answers1