read csv files into a list of data frames r

Question

I tried looking for the answer to this but I could only find how to create individual data frames from csv files. I have many csv files in my working directory, and instead of assigning them to individual data frames by

frame1 = read.csv(filepath)

I would like have them contained in a list of data frames that I could do operations on. This would obviously require a loop over the files in dir(), but I am not sure of the syntax. In java I would do List.add() for each element.

Thank you

QuantIbex · Accepted Answer · 2013-06-27T13:45:54.153

8

Something like the following might be helpful.

my.path <- list("filepath1", "filepath2", "filepath3")
my.data <- list()
for (i in 1:length(my.path)){
    my.data[[i]] <- read.csv(my.path[[i]])
}

my.data is a list containing data frames

EDIT

The previous answer shows how to dynamically assign elements of a list. However, a more compact way to achieve your task would be

my.path <- list("filepath1", "filepath2", "filepath3")
my.data <- lapply(my.path, read.csv)

edited Jun 27 '13 at 13:45

answered Jun 26 '13 at 23:17

QuantIbex

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ah thanks for the answer, but i get number of items to replace is not a multiple of replacement length – raj rajaratnam Jun 27 '13 at 13:43
Ok, so please provide a reproducible example that could be used to provide a solution. – QuantIbex Jun 27 '13 at 13:47
i tried the compact way before I saw your edit. Thats the way I did it. Thank you – raj rajaratnam Jun 27 '13 at 14:00
@Quantlbex I try this but now all the data files merge into one big frame, how do I separate or name them? – bvowe Mar 28 '19 at 18:16
Is there a way to do this without listing the file paths, say, if they were all in one folder that isn't a working directory? – jvalenti Nov 13 '19 at 15:52
1

@jvalenti I guess you could simply do `my.path <- as.list(list.files("folderpath"))`. – QuantIbex Nov 19 '19 at 11:59

read csv files into a list of data frames r

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