How to parse specific line in a text file in c#

Question

I need to parse a specific lines in a text file in which to begin by a specific words as in the following image :

I need to parse the lines that begins by "Level" only and extract the value of "Row" and "Col" only. Note that the text file will contain 6 groups of such data where each group starts by

---------------- chromosome : # ------------------

See the following sample : Sample

I need to save each group's row and columns in a separated list for each!!. Is there any way to perform this ?

I tried the following method :

public List<int[,]> getValuesFromTextFile(String filePath ) {

     IEnumerable<string> allLines = Enumerable.Empty<string>();

     List<int[,]> path = new List<int[,]>();

     int[,] item = new int[2,1];

    if (File.Exists(filePath))

        {
                    //Read all content of the files and store it to the list split with new line 
                    allLines = File.ReadLines(filePath);
        }
 
                    //all Level lines
                IEnumerable<string> levelLines = allLines.Where(d => d.StartsWith("Level", StringComparison.CurrentCultureIgnoreCase));
 
                foreach(string line in levelLines)

                {
                     string[] values= line.Split(':');//either space or tab or others as your file contain seperator  

                     for(int i=1; i <values.Length;i++)  {

                     string value = values[i];// skip index 0,it contains label, remaining are point data

                     if (i == 3) item[1,0] = Int32.Parse(value);

                     if (i == 5 && item[1,0] != null ) { item[0,0] = Int32.Parse(value);
                          path.Add(item);

                          }

                 }

        }



                return path;

        }

I got the following error at line( if (i == 3) item[1,0] = Int32.Parse(value); ) :

Input string was not in a correct format.

When I put a break point at this line I saw that the value of string "value" equal to null!!.

When I added a break point to see all lines list contents, I got as in the following image :

The above method needs to parse each group of levels separately!!.

Answer 1

You can use a named group Regex to parse the lines and build out a list of records.

void Main()
{
    var file = File.ReadLines(@"C:\TreeParser.txt");

    var groupRegex = new Regex(@"Chromosome : (?<Chromosome>[0-9])");
    var recordRegex = new Regex(@"Level : '(?<Level>[0-9])', Row : '(?<Row>[0-9])', Col : '(?<Col>[0-9])'");

    var groups = new List<Group>();

    foreach (var line in file)
    {
        var groupMatch = groupRegex.Match(line);
        if (groupMatch.Success)
        {
            groups.Add(new Group
            {
                Chromosome = int.Parse(groupMatch.Groups["Chromosome"].Value),
                Records = new List<Record>()
            });
        }

        var recordMatch = recordRegex.Match(line);
        if (!recordMatch.Success)
        {
            // No match was found
            continue;
        }

        var level = new Record
        {
            Level = int.Parse(recordMatch.Groups["Level"].Value),
            Row = int.Parse(recordMatch.Groups["Row"].Value),
            Col = int.Parse(recordMatch.Groups["Col"].Value)
        };

        groups.Last().Records.Add(level);
    }

    // groups now contains a list of each section from the file with a list of records
}

public class Record
{
    public int Level { get; set; }
    public int Row { get; set; }
    public int Col { get; set; }
}

public class Group
{
    public int Chromosome { get; set; }
    public List<Record> Records { get; set; }
}

Answer 2

Rose, you have two problems. First, splitting the text into groups, second parsing each line. 2nd one can easily be done with regex but I will use a json trick using Json.Net :)

int groupInx = 0;
var groupLines = File.ReadLines(@"d:\temp\a.txt")
                .GroupBy(x => x.Contains("Chromosome") ? ++groupInx : groupInx);

foreach(var group in groupLines)
{
    var lines = group.Skip(2) //skip ----- lines
                    .Select(x => JObject.Parse($"{{{x}}}"))
                    .ToList();

    //use a loop for each lines here
    int level = (int)lines[0]["Level"]; //for example
    int col = (int)lines[0]["Col"]; //for example

}

Answer 3

How about this:

   List<RowAndCol> lstrc = new List<RowAndCol>();
    private void Form1_Load(object sender, EventArgs e)
    {

        var file = File.ReadLines("E:\\SAMPLE_FILE\\sample.txt");

        var getList = (from f in file.ToList() where f.Contains("Level") || f.Contains("Chromosome") select f).ToList();
        int cnt = 1;

        string chr = string.Empty;
            foreach (var fl in getList.ToList())
            {

                RowAndCol rl = new RowAndCol();
                if (fl.Contains("Level"))
                {
                    String[] s = fl.Split(',');
                    String[] rowValue = s[1].Trim().Split(':');
                    String[] colValue = s[2].Trim().Split(':');

                    rl.Chromosome = chr;
                    rl.rownum = cnt;
                    rl.rowtext = "Row";
                    rl.coltext = "Col";
                    rl.row = rowValue[1].ToString();
                    rl.col = colValue[1].ToString();

                    cnt += 1;
                }
                else
                {
                    chr = fl.ToString();
                }

                lstrc.Add(rl);
            }
            cnt = 1;
    }
    public class RowAndCol
    {
        public int rownum { get; set; }
        public string Chromosome { get; set; }
        public String rowtext { get; set; }
        public String coltext { get; set; }
        public String row { get;set; }
        public String col { get; set; }
    }