If file exists in folder read it else skip the processing part

Question

I am reading in several *.csv, where the names and paths are determined at runtime.

However sometimes there are files with do not exist. For this file I need kind of exception handling.

Currently I am reading in my files with:

    companyFileName <- paste("C://Users//Prices//",companiesIsin,".csv")
df <- read.csv(gsub(" ","", companyFileName, fixed=TRUE), header = TRUE, sep = ";",stringsAsFactors=FALSE)

When the file does not exist in the folder I am getting an error. Is there something like exception handling in R?

I appreciate your reply!

Mark Heckmann · Accepted Answer · 2014-01-05T14:15:15.280

52

You can check if a file exists using the function file.exists. So you might check for file existence before trying to read it in to avoid an error, e.g.

if (file.exists(companyFileName))
   df <- read.csv(gsub(" ","", companyFileName, fixed=TRUE), header = TRUE, sep = ";",stringsAsFactors=FALSE)

EDIT: You may also simplify the creation of the path and use read.csv2 for the ; separator. This makes it a bit more readable.

f <- paste0("C://Users//Prices//",companiesIsin,".csv")
if (file.exists(f))
  df <- read.csv2(f, TRUE, stringsAsFactors=FALSE)

edited Jan 05 '14 at 14:15

answered Jan 05 '14 at 13:35

Mark Heckmann

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Thx for your answer! btw which path is it checking because I am always going into the `else` clause. btw I am running on windows 7. – user2051347 Jan 05 '14 at 14:02

score -1 · Answer 2 · edited Sep 26 '21 at 14:04

-1

This code can be used to check if a file exits in a folder with date format as TRUE or FALSE.

setwd("D:\\FILEFOLDER")

datafile<-file.exists(paste0('DATA_',format(Sys.Date()-1,'%Y%m%d'),'.gz'))

voicefile<-file.exists(paste0('VOICE_TEXT_',format(Sys.Date()-1,'%Y%m%d'),'.gz'))

edited Sep 26 '21 at 14:04

Adrian Mole

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answered Sep 26 '21 at 13:25

Rupesh Kumar

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If file exists in folder read it else skip the processing part

2 Answers2