Converting a csv file to json using C#

Question

I was wondering if someone\'s written a utility to convert a CSV file to Json using C#. From a previous question on stackoverflow, I\'m aware of this nice utility - https://

Answer 1

Taking only a dependency on Newtonsoft.Json, here's a helper method given an array of CSV lines, the first one being the header.

    public static IEnumerable<JObject> CsvToJson(IEnumerable<string> csvLines)
    {
        var csvLinesList = csvLines.ToList();

        var header = csvLinesList[0].Split(',');
        for (int i = 1; i < csvLinesList.Count; i++)
        {
            var thisLineSplit = csvLinesList[i].Split(',');
            var pairedWithHeader = header.Zip(thisLineSplit, (h, v) => new KeyValuePair<string, string>(h, v));

            yield return new JObject(pairedWithHeader.Select(j => new JProperty(j.Key, j.Value)));
        }
    }

Answer 2

Cinchoo ETL - an open source library available to do the conversion of CSV to JSON easily with few lines of code

For a sample CSV:

Id, Name, City
1, Tom, NY
2, Mark, NJ
3, Lou, FL
4, Smith, PA
5, Raj, DC

Sample code,

string csv = @"Id, Name, City
1, Tom, NY
2, Mark, NJ
3, Lou, FL
4, Smith, PA
5, Raj, DC
";

StringBuilder sb = new StringBuilder();
using (var p = ChoCSVReader.LoadText(csv)
    .WithFirstLineHeader()
    )
{
    using (var w = new ChoJSONWriter(sb))
        w.Write(p);
}

Console.WriteLine(sb.ToString());

Output JSON:

[
 {
  "Id": "1",
  "Name": "Tom",
  "City": "NY"
 },
 {
  "Id": "2",
  "Name": "Mark",
  "City": "NJ"
 },
 {
  "Id": "3",
  "Name": "Lou",
  "City": "FL"
 },
 {
  "Id": "4",
  "Name": "Smith",
  "City": "PA"
 },
 {
  "Id": "5",
  "Name": "Raj",
  "City": "DC"
 }
]

Checkout CodeProject article for some additional help.

UPDATE: If your CSV file has duplicate column names or no names, please use the below steps to produce the JSON file

string csv = @"Id, Name, 
1, Tom, NY
2, Mark, NJ
3, Lou, FL
4, Smith, PA
5, Raj, DC
";

StringBuilder sb = new StringBuilder();
using (var p = ChoCSVReader.LoadText(csv)
    .WithField("Id", position: 1)
    .WithField("Name", position: 2)
    .WithField("City", position: 3)
    .WithFirstLineHeader(true)
    )
{
    using (var w = new ChoJSONWriter(sb))
        w.Write(p);
}

Console.WriteLine(sb.ToString());

Disclaimer: I'm the author of this library.

Answer 3

I used Dictionary and returned json using newtonsoft

public string ConvertCsvFileToJsonObject(string path) 
{
    var csv = new List<string[]>();
    var lines = File.ReadAllLines(path);

    foreach (string line in lines)
        csv.Add(line.Split(','));

    var properties = lines[0].Split(',');

    var listObjResult = new List<Dictionary<string, string>>();

    for (int i = 1; i < lines.Length; i++)
    {
        var objResult = new Dictionary<string, string>();
        for (int j = 0; j < properties.Length; j++)
            objResult.Add(properties[j], csv[i][j]);

        listObjResult.Add(objResult);
    }

    return JsonConvert.SerializeObject(listObjResult); 
}

Answer 4

I use ChoETL:

using ChoETL;
using System.IO;

public class FromCSVtoJSON
{
    public FromCSVtoJSON()
    {

    }

    public void convertFile(string inputFile, string outputFile)
    {
        using (var writer = new ChoJSONWriter(outputFile))
        {
            using (var reader = new ChoCSVReader(inputFile).WithFirstLineHeader())
            {
                writer.Write(reader);
            }
        }
    }
}

Answer 5

Make sure you add the below in web.config before you do parse large csv files.

 <system.web.extensions>
       <scripting>
           <webServices>
               <jsonSerialization maxJsonLength="50000000"/>
           </webServices>
       </scripting>
   </system.web.extensions>

Answer 6

Try this and convert CSV to JSON object:

public static List<object> CsvToJson( string body, string[] column ) {
    if ( string.IsNullOrEmpty( body ) ) return null;
    string[] rowSeparators = new string[] { "\r\n" };
    string[] rows = body.Split( rowSeparators, StringSplitOptions.None );
    body = null;
    if ( rows == null || ( rows != null && rows.Length == 0 ) ) return null;
    string[] cellSeparator = new string[] { "," };
    List<object> data = new List<object>( );
    int clen = column.Length;
    rows.Select( row => {
        if ( string.IsNullOrEmpty( row ) ) return row;
        string[] cells = row.Trim( ).Split( cellSeparator, StringSplitOptions.None );
        if ( cells == null ) return row;
        if ( cells.Length < clen ) return row;
        Dictionary<object, object> jrows = new Dictionary<object, object>( );
        for ( int i = 0; i < clen; i++ ) {
            jrows.Add( column[i], cells[i]?.Trim( ) );
        }
        data.Add( jrows );
        return row;
    } ).ToList( );
    rowSeparators = null; rows = null;
    cellSeparator = null;
    return data;
}

var data = CsvToJson("csv_input_str", new string[]{ "column_map" })
string jsonStr = new JavaScriptSerializer { MaxJsonLength = int.MaxValue }.Serialize( data );