regex to parse csv

Question

I\'m looking for a regex that will parse a line at a time from a csv file. basically, what string.readline() does, but it will allow line breaks if they are within double q

Answer 1

The FileHelpers library is pretty good for this purpose.

http://www.filehelpers.net/

Answer 2

Using regex to parse CSV is fine for simple applications in well-controlled CSV data, but there are often so many gotchas, such as escaping for embedded quotes and commas in quoted strings, etc. This often makes regex tricky and risky for this task.

I recommend a well-tested CSV module for your purpose.

--Edit:-- See this excellent article, Stop Rolling Your Own CSV Parser!

Answer 3

Rather than relying on error prone regular expressions, over simpified "split" logic or 3rd party components, use the .NET framework's built in functionality:

Using Reader As New Microsoft.VisualBasic.FileIO.TextFieldParser("C:\MyFile.csv")

    Reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited

    Dim MyDelimeters(0 To 0) As String
    Reader.HasFieldsEnclosedInQuotes = False
    Reader.SetDelimiters(","c)

    Dim currentRow As String()
    While Not Reader.EndOfData
        Try
            currentRow = Reader.ReadFields()
            Dim currentField As String
            For Each currentField In currentRow
                MsgBox(currentField)
            Next
        Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
            MsgBox("Line " & ex.Message &
            "is not valid and will be skipped.")
        End Try
    End While
End Using