CSV to Dictionary - All credit to Sloane Kelly

CardClass.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Card
{

    public int CardID { get; set; }
    public int CardLvl { get; set; }
    public bool CardPlayed { get; set; }
    public string CardText { get; set; }

    public Card(int cardID, int cardLvl, bool cardPlayed, string cardText)
    {
        CardID = cardID;
        CardLvl = cardLvl;
        CardPlayed = cardPlayed;
        CardText = cardText;
    }

    public Card()
    {
        CardID = 0;
        CardLvl = 0;
        CardPlayed = false;
        CardText = "";

    }
}

DeckBuilder.cs

using System.Collections.Generic;
using System.IO;
using UnityEngine;
using System.Linq;
using LINQtoCSV;

public class DeckBuilder : MonoBehaviour {

    private Dictionary<int, Card> CompleteDeck = new Dictionary<int, Card>();

    [Tooltip("The file that contains the list to be converted to cards")]
    public TextAsset CardList;


    //I thought that I might be able to call this whenever I wanted - the same with the custom deck builder.
    //but when I put this into anything that isn't a start function..
    //I get the following error:
    //NullReferenceException: Object reference not set to an instance of an object
    //DeckBuilder.CreateDeck () (at Assets/Scripts/DeckBuilder.cs:32)
    //DeckBuilder.ReturnLevelDeck (Int32 level) (at Assets/Scripts/DeckBuilder.cs:60)
    //GameController.TestStart () (at Assets/Scripts/GameController.cs:27)
    //
    //I'm also continually being nagged about using a "new monobehaviour" instead of finding a gameobject
    
    //private void CreateDeck()
    void Start()
    {
        CompleteDeck.Clear();

        CsvFileDescription inputFileDescription = new CsvFileDescription
        {
            SeparatorChar = ',',
            FirstLineHasColumnNames = true
        };

        using (MemoryStream ms = new MemoryStream())
        {
            using (StreamWriter txtWriter = new StreamWriter(ms))
            {
                using (StreamReader txtReader = new StreamReader(ms))
                {
                    txtWriter.Write(CardList.text);
                    txtWriter.Flush();
                    ms.Seek(0, SeekOrigin.Begin);
                    CsvContext cc = new CsvContext();
                    cc.Read<Card>(txtReader, inputFileDescription)
                        .ToList()
                        .ForEach(card =>
                       {

                           CompleteDeck[card.CardID] = new Card
                           {
                               CardLvl = card.CardLvl,
                               CardPlayed = card.CardPlayed,
                               CardText = card.CardText,
                           };
                       });

                }
            }
        }
        //(Text, P1, P1Gender, P2, P2Gender, P3, P3Gender, P4, P4Gender);
        string output = string.Format((CompleteDeck[2].CardText), "a", "b");
        Debug.Log(output);
    }


    public Dictionary<int, Card> ReturnLevelDeck(int level)
    {
        //CreateDeck();
        Debug.Log(CompleteDeck.Count);
        Dictionary<int, Card> returnDictionary = new Dictionary<int, Card>();
        for(int i = 0; i< CompleteDeck.Count; i++)
            if (CompleteDeck[i].CardLvl == level)
            {
                Debug.Log("found");
                returnDictionary.Add(CompleteDeck[i].CardID, CompleteDeck[i]);
            }
        return returnDictionary;

    }
}

GameController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;
using System.Linq;
using System;

public class GameController : MonoBehaviour
{

    private DeckBuilder Deck = new DeckBuilder();



    public void QuitGame()
    {
        Application.Quit();
    }




    public void TestStart()
    {
        //string output = string.Format((Deck.CompleteDeck[2].CardText), "a", "b");
        Dictionary<int, Card> Level0Cards = Deck.ReturnLevelDeck(0);


        //I appreciate that this doesn't make any proper use of the IEnumerable nature of the dictionary, but I wanted to see what was going on..
        for(int i = 0; i < Level0Cards.Count; i++)
        {
            string retstring = string.Format((Level0Cards[i].CardText), "James", "Bob");
            Debug.Log(retstring);
        }
    }

    //TEST CODE ONLY DOWN HERE


}

List.csv