Newby) filter rows from csv using linq

Hi,

My final goal is to use data from a csv-file to instantiate filtered objects in Unity (with c#). The first step is to couple a csv in Unity.

Linq is a very interesting way to achieve this. Next to csv, it can also be used to harvest other data sources.

I found an interesting example on the website of Microsoft:
https://docs.microsoft.com/en-us/do...compute-column-values-in-a-csv-text-file-linq

My csv file looks like this:

To use it in Unity I converted the example:

Code (CSharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5. using UnityEngine.UI;
6. using System.Linq;
7. using System;
8.  
9. public class Linqtest : MonoBehaviour
10.    
11. {
12.     public string output = "";
13.     public float A = 35f, B = 150f, C = 750f, D = 400f;
14.  
15.     public Text teksten;
16.  
17.     public string[] line;
18.  
19.     void Start()
20.    
21.     {
22.    
23.         string[] lines = System.IO.File.ReadAllLines("./Assets/LINQ/Scores.csv");
24.  
25.         MultiColumns(lines);
26.  
27.     }
28.     public void MultiColumns(IEnumerable<string> strs)
29.     {
30.        
31.         IEnumerable<IEnumerable<int>> multiColQuery =
32.  
33.            
34.             from line in strs
35.             let elements = line.Split(',')
36.             let scores = elements.Skip(1)
37.             select (from str in scores
38.                     select Convert.ToInt32(str));
39.  
40.     var results = multiColQuery.ToList();
41.  
42.             // Loop en berekenen Queries:
43.  
44.         int columnCount = results[0].Count();
45.        
46.         output = "";
47.  
48.         for (int column = 0; column < columnCount; column++)
49.         {
50.             var results2 = from row in results
51.                            select row.ElementAt(column);
52.    
53.             double average = results2.Average();
54.             int max        = results2.Max();
55.             int min        = results2.Min();
56.             int sum        = results2.Sum();
57.  
58.             output = output + (string.Format("Examennummer #{0} Gemiddelde: {1:##.##} Beste Score: {2} Laagste Score: {3} Opgeteld: {4}",
59.                           column + 1, average, max, min, sum));
60.             output = output + "\n";
61.         }
62.     }
63.     void OnGUI()
64.     {
65.         GUI.Label(new Rect(A, B, C, D), output);
66.     }
67. }
68.  

Like you can see, the results are columns. I've spend some evenings to convert the code that it shows rows. Unfortunately without a good result.

Can someone advise me how I can show the rows filtered by the first column?
For example, show the data from rows called A.


Thanks in advance,

Louis

 

You can do it like this:

Code (CSharp):

1. var fiteredResults = System.IO.File.ReadAllLines("./Assets/LINQ/Scores.csv")
2.     .Select(l=>l.Split(',').Select(s=>s.Trim()).ToArray())
3.     .Where(a=>a[0] == "A");
4.  
5. foreach (var filteredResult in fiteredResults)
6. {
7.     Debug.Log(String.Join(",", filteredResult));
8. }

or if you prefer:

Code (CSharp):

1. var fiteredResults =
2.  from a in (from l in System.IO.File.ReadAllLines("./Assets/LINQ/Scores.csv") select (from s in l.Split(',') select s.Trim()).ToArray()) where  a[0] == "A" select a;
3.  
4. foreach (var filteredResult in fiteredResults)
5. {
6.     Debug.Log(String.Join(",", filteredResult));
7. }

 

Thank you very much for the answer Fido!

I hope to test it today.

Regards Louis

 

tested?

 

Also slow, and not very garbage allocation friendly.

Although this is a necropost (kinda), people should know that this is far from optimal.