How to Read Multiple Csv Files in a Folder in Matlab

Oft we face the challenge of having to merge csv files or txt files in a folder, into a single file. Excel is the obvious tool for such tasks and today I will evidence a couple of easy ways for merging multiple files, in a single or fifty-fifty a whole structure of folders, into a unmarried CSV or text file. To merge csv files or other text files information technology is often best to utilise Visual Bones for Applications in Excel.

Let's first with the simplest approach using Windows Command line without having to utilize Excel.

Merge CSV files using Windows CMD

This approach uses the Windows Command line Re-create control.

Open the binder which should contain your CSV or TXT files

Open in Windows Explorer the folder containing CSV or TXT files to exist merged. These should be without headers or merely the get-go file should exist with headers.

Open up CMD control line within folder

Click on the filepath of the Windows Explorer window and type cmd and hit ENTER.

Merge the files using Re-create command

The CMD Windows control line Window should open. Type the following control and striking ENTER to merge files

copy *.csv merge.csv        

The upshot will be the newly created merge.csv file with merged data across all CSV files within the directory.

Simply replace *.csv with *.txt to merge text files instead of CSV files

Merge listing of csv, txt files

The previous method was very unproblematic and didn't require the use of Excel or MS Office. The below and the following approaches volition provided you lot with more flexibility when merging files. If you lot don't know how to use Macros in Excel read my Tutorial showtime.

Assuming you desire to merge a list of files in a String Assortment you can use the process beneath. Information technology volition merge all provided csv or text files into a single new text file.

Sub MergeFiles(fileNames() Every bit Cord, newFileName Equally String, Optional headers As Boolean = True, Optional addNewLine Equally Boolean = False)     Dim fileName As Variant, textData As String, fileNo As Integer, effect As Cord, firstHeader As Boolean     firstHeader = True     For Each fileName In fileNames         fileNo = FreeFile         Open fileName For Input As #fileNo         textData = Input$(LOF(fileNo), fileNo)         Shut #fileNo         If headers And then             effect = issue & IIf(addNewLine, vbNewLine, "") & IIf(firstHeader, textData, Correct(textData, Len(textData) - InStr(textData, vbNewLine)))             firstHeader = False         Else             result = result & IIf(addNewLine, vbNewLine, "") & textData         End If     Next fileName     fileNo = FreeFile     Open up newFileName For Output As #fileNo     Print #fileNo, upshot     Close #fileNo End Sub        

Merge csv, txt files example

Come across an case beneath of how to employ the MergeFiles process:

Dim fileNames(0 To ane) As String fileNames(0) = "C:\somefolder\examination.csv" fileNames(1) = "C:\somefolder\test1.csv"      MergeFiles fileNames, "C:\Merged.csv", True, False        

MergeFiles Parameters

fileNames()
Array of Strings representing full file paths to files that are to be merged

newFileName
The name of the new merged file that is to be created

headers
Optional. True by default. This is meant for CSV TXT files (HDR). If True assumes that all files accept headers (first row with columns). Only kickoff header volition be merged into the new file (newFileName)

addNewLine
Optional. Simulated by default. If True a new line (vbNewLine) character will be added between each merged file

Merge csv, txt files inside specified folder

Another case is when you lot want to merge all csv files within a unmarried folder. This process is like to the previous one with the exception that information technology runs through all files within a single directory (excluding subdirectories – for that scroll to next procedure). You can also use wildcards such every bit "*.csv" to exist sure that but csv files are merged a not other files – read my post on the VBA Dir function to acquire more.

Sub MergeFilesInFolder(folderName Equally String, newFileName As String, Optional headers Equally Boolean = Truthful, Optional addNewLine As Boolean = False)     Dim fileName As Variant, textData Every bit String, fileNo As Integer, consequence Every bit Cord, firstHeader As Boolean     firstHeader = True     fileName = Dir(folderName)     Do Until fileName = ""         fileNo = FreeFile         Open (Left(folderName, InStrRev(folderName, "\")) & fileName) For Input As #fileNo         textData = Input$(LOF(fileNo), fileNo)         Close #fileNo         If headers Then             upshot = effect & IIf(addNewLine, vbNewLine, "") & IIf(firstHeader, textData, Right(textData, Len(textData) - InStr(textData, vbNewLine)))             firstHeader = Faux         Else             result = result & IIf(addNewLine, vbNewLine, "") & textData         End If         fileName = Dir     Loop     fileNo = FreeFile     Open newFileName For Output As #fileNo     Print #fileNo, result     Close #fileNo Finish Sub        

Merge csv, txt files in binder example

Run across an example beneath of how to employ the MergeFilesInFolder process:

MergeFilesInFolder "C:\somefolder\*.csv", "C:\MergedFolder.csv", True, False        

MergeFilesInFolder Parameters

folderName
A binder including all files to be merged. Wildcards are permitted if supported by the VBA Dir role

newFileName
The proper name of the new merged file that is to be created

headers
Optional. True by default. This is meant for csv files (HDR). If True assumes that all files have headers (commencement row with columns). But first header volition be merged into the new file (newFileName)

addNewLine
Optional. Fake by default. If True a new line (vbNewLine) character will be added between each merged file

Merge csv, txt files within all subfolders

The most complex case is when you lot want to merge files not merely inside a certain directory but besides within all subdirectories. This volition equally work for a scenario when in that location are no subfolders.

Sub MergeFilesInSubFolders(folderName As Cord, blueprint As String, newFileName Every bit String, Optional headers As Boolean = True, Optional addNewLine As Boolean = False)     Dim fileName Every bit Variant, folder As Variant, textData As String, fileNo As Integer, result As String, firstHeader As Boolean     firstHeader = Truthful     Dim col Every bit Drove     Gear up col = New Collection     col.Add folderName     TraversePath folderName, col     For Each binder In col         fileName = Dir(folder & pattern)         Do Until fileName = ""             fileNo = FreeFile             Open (Left(folder, InStrRev(binder, "\")) & fileName) For Input Every bit #fileNo             textData = Input$(LOF(fileNo), fileNo)             Close #fileNo             If headers So                 result = outcome & IIf(addNewLine, vbNewLine, "") & IIf(firstHeader, textData, Right(textData, Len(textData) - InStr(textData, vbNewLine)))                 firstHeader = Fake             Else                 upshot = result & IIf(addNewLine, vbNewLine, "") & textData             Cease If             fileName = Dir         Loop     Next folder     fileNo = FreeFile     Open newFileName For Output Every bit #fileNo     Print #fileNo, effect     Close #fileNo Finish Sub  Function TraversePath(path As Variant, allDirCollection Equally Drove)     Dim currentPath As Cord, directory As Variant     Dim dirCollection As Drove     Set dirCollection = New Collection           currentPath = Dir(path, vbDirectory)     'Explore current directory     Do Until currentPath = vbNullString         If Left(currentPath, 1) <> "." And Left(currentPath, 2) <> ".." And _             (GetAttr(path & currentPath) And vbDirectory) = vbDirectory Then             dirCollection.Add path & currentPath & "\"             allDirCollection.Add path & currentPath & "\"         End If         currentPath = Dir()     Loop           'Explore subsequent directories     For Each directory In dirCollection         TraversePath directory, allDirCollection     Next directory Cease Role        

Read this post to larn more on using the VBA Dir function to traverse directories and subdirectories

Merge csv, txt files inside subfolders example

Meet an example below of how to use the MergeFilesInSubFoldersprocess:

MergeFilesInSubFolders "C:\somefolder\", "C:\MergedSubFolders.csv", True, False        

MergeFilesInSubFolders Parameters

folderName
A binder with or without subfolders including all files to be merged. Utilise wildcards with pattern parameter

pattern
If needed a pattern using wildcards permitted past the VBA Dir function

newFileName
The name of the new merged file that is to be created

headers
Optional. True by default. This is meant for csv files (HDR). If True assumes that all files accept headers (beginning row with columns). Merely kickoff header will exist merged into the new file (newFileName)

addNewLine
Optional. Faux by default. If Truthful a new line (vbNewLine) graphic symbol will be added between each merged file

Merge CSV files – filter records

Sometimes nosotros want to download just a subset of records in our CSV files. One way is uploading the data and and then filtering information technology in Excel. But why non do it in 1 go? Run into my SQL AddIn or my read CSV file using SQL case in this post here.

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Source: https://analystcave.com/merge-csv-files-or-txt-files-in-a-folder/

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