How can I retrieve data from multiple objects from a .csv file using CsvHelper?

Question

I have a list with type MyClass, and MyClass has several attributes. How can i retrieve data using CsvHelper, if .csv file looks like this? (Yes, attributes of type Data1 are numbered.)

Date       |   Data1  | Unit  |   Data2  | Unit  |   Data3  | Unit  | ... | DataN    |   Unit 
-----------|----------|-------|----------|-------|----------|-------|-----|----------|----------
2020.01.02 |     1    |   kW  |     3    |  kW   |    1.5   |  kW   | ... |     0    |    kW
2020.01.03 |     0    |   kW  |     4    |  kW   |     1    |  kW   | ... |     3    |    kW
2020.01.04 |     4    |   kW  |     2    |  kW   |     1    |  kW   | ... |     2    |    kW

This is what i want to see. The objects are stored in a list that can store MyClass type.

    List(MyClass) = [Object-1, Object-1, Object-3, ..., Object-N]

Object-1: [(2020.01.02.,1, kW),(2020.01.03.,0, kW),,(2020.01.04.,4, kW)]
Object-2: [(2020.01.02.,3, kW),(2020.01.03.,4, kW),,(2020.01.04.,2, kW)]
Object-3: [(2020.01.02.,1.5, kW),(2020.01.03.,1, kW),,(2020.01.04.,1, kW)]
...
Object-N: [(2020.01.02.,0, kW),(2020.01.03.,3, kW),,(2020.01.04.,2, kW)]

    MappedClass{
        private DateTime Date;
        private List List;
    }

    MyClass{
        private DateTime Date;
        private string A1; //Attribute1
        private int A2; //Attribute2
    }

If the properties of only one object are listed, then i can do the task, but not with multiple objects and this layout. I thought of reading the file row by row and then somehow pairing its related data.

How to do this task effectively?

Answer 1

This would be one way to do it.

public class Program
{
    public static void Main(string[] args)
    {
        using (MemoryStream stream = new MemoryStream())
        using (StreamWriter writer = new StreamWriter(stream))
        using (StreamReader reader = new StreamReader(stream))
        using (CsvReader csv = new CsvReader(reader, CultureInfo.InvariantCulture))
        {
            writer.WriteLine("Date,Data1,Unit,Data2,Unit,Data3,Unit");
            writer.WriteLine("2020.01.02,1,kw,3,kw,1.5,kw");
            writer.WriteLine("2020.01.03,0,kw,4,kw,1,kw");
            writer.Flush();
            stream.Position = 0;

            var records = new List<MappedClass>();

            csv.Read();
            csv.ReadHeader();

            while (csv.Read())
            {
                var record = new MappedClass
                {
                    Date = record.Date,
                    Date = csv.GetField<DateTime>(0),
                    List = new List<MyClass>()
                };

                for (int i = 1; i < csv.Context.HeaderRecord.Length; i += 2)
                {
                    var item = new MyClass
                    {
                        Data = csv.GetField<decimal>(i),
                        Unit = csv.GetField<string>(i + 1)
                    };

                    record.List.Add(item);
                }

                records.Add(record);
            }
        }
    }
}

public class MappedClass
{
    public DateTime Date { get; set; }
    public List<MyClass> List { get; set; }
}

public class MyClass {
    public DateTime Date;
    public string Unit; //Attribute1
    public decimal Data; //Attribute2
}