What is the best way to get the list of column names using CsvHelper?

Question

I am trying to use CsvHelper for a project. I went through the documentation but I couldn't find a way to read all the column names with a single method. How can I get a list of all column header names easily with CsvHelper? I am doing it like this currently but I assume there is a better way.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using CsvHelper;
using System.IO;

namespace Kg
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var reader = new StreamReader(@"myfile.csv"))
            {
                var csv = new CsvReader(reader);

                csv.Read();                  
                var has_header = true;
                var csv_headers = new List<string>();
                var header_index = 0;
                while (has_header)
                {
                    has_header = csv.TryGetField<string>(header_index, out string header_name);

                    if (has_header)
                    {
                        header_index += 1;
                        csv_headers.Add(header_name);

                    }

                }

                Console.WriteLine(csv_headers.Count);

            }
        }
}

*Usually* you know what the data represents, so if you create a class to hold the imported data, CSVHelper will create typed objects for you and put them in a collection. — Ňɏssa Pøngjǣrdenlarp, Jan 17 '18 at 18:16
As far as I know the header of a csv file is just the first row. — derloopkat, Jan 17 '18 at 18:20
@Plutonix, thanks yes I agree, but there are more than 50 columns and I want to make a reusable class where I can just get the use the header names by parsing the csv file and setting the type based on the first few rows of each column. — B A, Jan 17 '18 at 18:20
@derloopkat yes and its easy to get the column names present in the first row by their index(csv[0]), but there is no easy way to get the count of columns. — B A, Jan 17 '18 at 18:21
Still simpler to create a class - even with 50 props - than to read and parse and guestimate data type — Ňɏssa Pøngjǣrdenlarp, Jan 17 '18 at 18:21
@IsaacKleinman `ReadHeader()` is just the same. No way to get the total count. — B A, Jan 17 '18 at 18:22
If you are intent on doing it that way you probably want to use the CSVParser approach not the CSVReader — Ňɏssa Pøngjǣrdenlarp, Jan 17 '18 at 18:24
@Plutonix actually I think I will be playing around with multiple csv files so adding the properties all the time would take up a lot of time :) Could you please give a link to the documentation for the CSVParser? I couldn't find it. — B A, Jan 17 '18 at 18:29
Possible duplicate of [How to read a header from a specific line with CsvHelper?](https://stackoverflow.com/questions/39641220/how-to-read-a-header-from-a-specific-line-with-csvhelper) — derloopkat, Jan 17 '18 at 18:37

score 58 · Accepted Answer · answered Jan 17 '18 at 18:33

58

The header record is on the csv context. It needs to be read beforehand before accessing.

csv.Read();
csv.ReadHeader();
string[] headerRow = csv.Context.HeaderRecord;

answered Jan 17 '18 at 18:33

Paul Wild

608
6
10

3

for a newer version: `csv.Context.Reader.HeaderRecord` – Musa Biralo Apr 12 '22 at 21:38
It is called `csv.HeaderRecord` in 2022. – dotNET May 31 '22 at 07:42

JumpingJezza · Answer 2 · 2021-02-16T01:57:43.857

7

The previous answer used to work fine, but as of version 20 of csvhelper there is a breaking change. Now just access the header record from the reader directly:

csv.Read();
csv.ReadHeader();
string[] headerRow = csv.HeaderRecord;

edited Feb 16 '21 at 01:57

answered Feb 16 '21 at 01:51

JumpingJezza

5,498
11
67
106

1

NOTE: These are the unmunged headers. If you use `PrepareHeaderForMatch` to munge the headers (replace whitespace with underscores, for instance) that won't be reflected in the `HeaderRecord` list. – amonroejj Mar 17 '21 at 16:31

What is the best way to get the list of column names using CsvHelper?

2 Answers2

Linked