unzip in an R package

[sgermani]

I currently have some code in an R package that unzips and reads in a CSV file. Reproducible example here:

url <- paste0("http://mba.tuck.dartmouth.edu/pages/faculty/ken.french/ftp/F-F_Momentum_Factor_CSV.zip")

temp <- tempfile()
download.file(url,temp,quiet=TRUE,mode="wb")

data <- data.table::fread(unzip(file.path(temp)),fill=TRUE,skip=13)

This leaves a CSV file in my working directory. What is the best practice way to do this without leaving a CSV in the users directory? I've tried unzipping to a temp file but fread doesn't seem to like reading that in.

[pieterjanvc]

Hi,

In my case the code seems to work, but it might be related to file permissions set in the temp folder you have..

I also can think of another way of doing all of it in the working directory

url <- paste0("http://mba.tuck.dartmouth.edu/pages/faculty/ken.french/ftp/F-F_Momentum_Factor_CSV.zip")
download.file(url, "myFile.zip", quiet=TRUE,mode="wb")
data <- data.table::fread(unzip(file.path("myFile.zip")),fill=TRUE,skip=13)
file.remove("myFile.zip")

Of course you can make it safer my checking if the file myFile.zip does not exist yet using the file.exists function

Hope this helps,
PJ

[sgermani]

Thanks for the reply. My code does get rid of the zip file but I am still left with the unzipped CSV file (F-F_Momentum_Factor.CSV) in my working directory. I am trying to find a solution to stop the unzipped file from going to the working directory and ideally without having to know the name of the file in advance as I could obviously just use file.remove on the unzipped file if I know the name in advance.

[pieterjanvc]

HI,

My bad, I didn't get the part where you wanted to get rid of the csv file

Would this work?

url <- paste0("http://mba.tuck.dartmouth.edu/pages/faculty/ken.french/ftp/F-F_Momentum_Factor_CSV.zip")

tempDir <- tempdir()
tempFile <- tempfile()

download.file(url,tempFile,quiet=TRUE,mode="wb")

data <- data.table::fread(unzip(file.path(tempFile), exdir = tempDir),fill=TRUE,skip=13)

Here, I unzip to a temp folder and a temp file without ever having to know the name of the file itself. You can see in the temp folder/file assigned to the variables in case you would like to double check.

Hope this helps,
PJ

[sgermani]

That is it. Nice and simple. Thanks.