How to read Multiple CSV files in multiple sub folders

Hi,

I want to read multiple csv files in a subfolder(s). I have a main folder, in this main folder many sub folders (here two). I want to read each sub folder, and merge all csv in that subfolder. The merged CSV file name should be the respective subfolder name.

I use the following code, but I am unable to proceed after that, I do not know how to read each subfolder and merge the CVS files.

After merged, I want to read each CSV from output folder, and extract the data in column E (Score).

Kindly some one help.

clc;
clear all;
close all;
inputFolder='D:\Mekala_Backupdata\Matlab2010\InputData';
outputFolder='D:\Mekala_Backupdata\Matlab2010\OutputData';
expList=dir(inputFolder);
isub=[expList(:).isdir];
expID={expList(isub).name};

Answer 1

[Image Analyst]

You need to use genpath() to generate a list of all subfolders. Then you can use fullfile() and dir() to get a list of csv files in each one. See attached demo.

I would not use cd(). See the FAQ. I'd use fullfile() instead.

Answer 2

[J. Webster]

Not sure exactly how you want to merge the csvs, but the basic way to run through all the directories is this...

inputFolder='D:\Mekala_Backupdata\Matlab2010\InputData';
cd(inputFolder);
directories = getDirs()
for i=1:length(directories);
    mergeFilename = strcat(directory(i).name,'.csv'); %new filename is subfolder name with csv extention.
    cd(directory(i).name);
    files = dir('*.csv');    %you want just .csv
    for j=1:length(files)    
       ...merge your csv files here...
    end

    cd ..;   % or cd(inputFolder);
end

Answer 3

[Meade]

This may get you started:

mainFolder = uigetdir();    % Selectyour Main folder 
[~,message,~] = fileattrib([mainFolder,'\*']);
fprintf('\n There are %i total files & folders.\n',numel(message));

 allExts = cellfun(@(s) s(end-2:end), {message.Name},'uni',0); % Get exts
 CSVidx = ismember(allExts,'csv');    % Search ext for "CSV" at the end 

 CSV_filepaths = {message(CSVidx).Name};  % Use CSVidx to list all paths.
 fprintf('There are %i files with *.CSV exts.\n',numel(CSV_filepaths));

 for ii = 1:numel(CSV_filepaths)
    file(ii)= importdata(CSV_filepaths{ii}) % Your parsing will be different
 end