Split CSV files c#

Splitting logic of a CSV files into n number of files with .csv extension

Code Snippet:

for (int i = 1; i <= noOfFiles; i++)

{

    take = i == 1 ? finsPerCsv + mod : finsPerCsv;

    var fins = AllFins.GetRange(beginIndex, take);

    groupByfins.Add(fins);

    List<string> listw = masterData_raw.Where(item => col1Data.Any(category => category.col1.Equals(CSVParser2.Split(item)[0].Replace("\"", ""))));

    List<Items> list = masterData_cls.Where(item => col1Data.Any(category => category.col1.Equals(item.col1)));

   var csvFormattedData = list.Select(str =>

   "\"" + str.col1

   + "\",\"" + str.col2

   + "\",\"" + str.col3

   + "\",\"" + str.col4

   + "\",\"" + str.col5)

       .ToArray();

   csvHeader.CopyTo(csvFormattedData, 0);

   File.WriteAllLines(filepath, csvFormattedData);

   beginIndex = beginIndex + take;

}

Read CSV File c#

File Class - It is having methods for creation, copying, deletion, moving and opening of a single file.

Code Snippet:

List<string> masterDataList = File.ReadLines(filepath).ToList();

System.Text.RegularExpressions.Regex CSVParser = new System.Text.RegularExpressions.Regex(",(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))");

var columnData = masterDataList.Select(line =>

{

    String[] split = CSVParser.Split(line);

    string column = split[6].Replace("\"", "");

    return column;

}).ToList<string>();

Scenarios

var masterList = File.ReadLines(filePath).ToList();

System.Text.RegularExpressions.Regex CSVParser = new System.Text.RegularExpressions.Regex(",(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))");

List<Items> items_MasterData = File.ReadLines(filePath).Select(line =>

{

Items ch = new Items();

System.Text.RegularExpressions.Regex CSVParser = new System.Text.RegularExpressions.Regex(",(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))");

String[] split = CSVParser.Split(line);

       ch.col1 = split[0].Replace("\"", "");

       ch.col2 = split[1].Replace("\"", "");

       return ch;

}).ToList<Items>(); 

// CSV files having multiple rows based on col1, so grouping them by col1 data

var group = (from d in items_MasterData

             select new Items

             {

                 col1 = d.col1,

                 col2 = d.col2

             }).GroupBy(n => new { n.col1 })

               .Select(g => g.FirstOrDefault());

//int countCol1Data = items_MasterData.Select(x => x.col1).Distinct().Count();

           

List<Items> col1Data = items_MasterData.GroupBy(n => new { n.col1 }).Select(g => g.FirstOrDefault()).ToList();