Create a list with empty files and a list with not empty files

Question

I've got a lot of files in a folder, many of them are empty and others with data inside.

What I'm trying to do is this:

#Load all data in a list
file_all <- list.files(file.path(getwd(), "testall"), pattern = "\\.txt$")

Using this list, I'm trying to skip empty files using the method explained by @nrussell How to skip empty files when importing text files in R?

library(plyr)
df_list <- lapply(files, function(x) {
    if (!file.size(x) == 0) {
        list.files(x)
    }
})

And (not empty files)

    df_list2 <- lapply(files, function(x) {
    if (file.size(x) == 0) {
        list.files(x)
    }
})

The difference between @nrussell and mine is that I want to create a list of empty files and another list with not empty files. I'd like to know how many files are empty and how many are not empty.

Why don't you store the files in two different vectors using an `apply` function. — Eli Sadoff, Nov 03 '16 at 14:09
@EliSadoff that was a mistake, sorry. I'm storing in two different vectors. — Enrique, Nov 03 '16 at 14:13
Do this: list.of.files <- file.info(dir()) sizes <- file.info(dir())$size list.of.non.empty.files <- rownames(list.of.files)[which(sizes != 0)] And then of course you have to read in from the list of non empty files list.of.empty.files <- rownames(list.of.files)[which(sizes == 0)] — USER_1, Nov 03 '16 at 14:17
Please show current and desired results. Specifically, show why your current attempt does not work? Errors? Undesired output? Illustrate with actual data. — Parfait, Nov 03 '16 at 14:28

score 3 · Accepted Answer · answered Nov 03 '16 at 14:30

# create a list of files in the current working directory
list.of.files <- file.info(dir())

# get the size for each file
sizes <- file.info(dir())$size

# subset the files that have non-zero size
list.of.non.empty.files <- rownames(list.of.files)[which(sizes != 0)]

# here you can further subset that list by file name, eg - if I only want all the files with extension .mp3
list.of.non.empty.files[grep( ".mp3", list.of.non.empty.files)]


# get the empty files
list.of.empty.files <- rownames(list.of.files)[which(sizes == 0)]

Create a list with empty files and a list with not empty files

1 Answers1