C# load csv file and group by and aggregate results

Question

0.00/5 (No votes)

See more:

if I have a file:

name    state      ClosetSize    childGender
Hank    OK         2               M
Hank    OK         1               F
Wilbur  TX         1               F
Wilbur  TX         2               F
Tom     CA         3               M
Tom     CA         4               M
Zed     VT         1               M
Zed     VT         2               M
Zed     VT         3               F

I want to output a file if the combined total closet size of only the people that has BOTH at least one female (F) and at least one (M). Then output that to another csv. file.

I would expect that to be only Hank and Zed

What I have tried:

I've tried loading this into a list and using Linq

Posted 6-Nov-17 9:43am

Member 13506556

Updated 7-Nov-17 6:07am

Patrice T

v2

Add a Solution

Comments

Richard Deeming 6-Nov-17 16:01pm

Where's the code you've tried, and what was the problem with it?

Member 13506556 6-Nov-17 17:40pm

looking for a good structure to begin. Load, aggregate, export. I don't have a viable starting point.

2 solutions

Solution 1

try

DataTable dt = new DataTable();
           dt.Columns.Add("name");
           dt.Columns.Add("state");
           dt.Columns.Add("ClosetSize");
           dt.Columns.Add("childGender");
           dt.Rows.Add("Hank", "OK", 2, "M");
           dt.Rows.Add("Hank", "OK", 1, "F");
           dt.Rows.Add("Wilbur", "tx", 1, "F");
           dt.Rows.Add("Wilbur", "tx", 2, "F");
           dt.Rows.Add("Tom", "ca", 3, "M");
           dt.Rows.Add("Tom", "ca", 4, "M");
           dt.Rows.Add("Zed", "VT", 1, "M");
           dt.Rows.Add("Zed", "VT", 2, "M");
           dt.Rows.Add("Zed", "VT", 3, "F");

           DataTable dtOutput = dt.Clone();
           string[] names = dt.Rows.OfType<DataRow>().Select(k => k["name"] + "").Distinct().ToArray();
           foreach (string name in names)
           {
               var tempRows = dt.Select("name='" + name + "'");
               if (tempRows.Length > 1)
               {
                   string[] genders = tempRows.Select(k => k["childGender"] + "").Distinct().ToArray();
                   if (genders.Contains("M") && genders.Contains("F"))
                       foreach (DataRow row in tempRows)
                           dtOutput.Rows.Add(row.ItemArray);
               }
           }

refer this to convert csv to datatable and vice versa
Read CSV File into Data Table[^]
Export Datatable to CSV Using Extension Method[^]

Posted 6-Nov-17 20:17pm

Karthik_Mahalingam

Updated 6-Nov-17 20:19pm

v2

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Accepted Answer · 2017-11-07T01:57:00

Another option, using CsvHelper[^]:

C#

struct SourceRecord
{
    public string name { get; set; }
    public string state { get; set; }
    public int ClosetSize { get; set; }
    public char childGender { get; set; }
    
    public static IReadOnlyCollection<SourceRecord> Load(TextReader reader)
    {
        var csv = new CsvReader(reader);
        return csv.GetRecords<SourceRecord>().ToList();
    }
    
    public static IReadOnlyCollection<SourceRecord> LoadFrom(string fileName)
    {
        using (var reader = File.OpenText(fileName))
        {
            return Load(reader);
        }
    }
}

struct OutputRecord
{
    public string name { get; set; }
    public string state { get; set; }
    public int ClosetSize { get; set; }
    
    public static void Save(TextWriter writer, IEnumerable<OutputRecord> records)
    {
        var csv = new CsvWriter(writer);
        csv.WriteRecords(records);
    }
    
    public static void SaveTo(string fileName, IEnumerable<OutputRecord> records)
    {
        using (var writer = new StreamWriter(fileName))
        {
            Save(writer, records);
        }
    }
}

static void Process(string inputFile, string outputFile)
{
    IReadOnlyCollection<SourceRecord> input = SourceRecord.LoadFrom(inputFile);
    
    IEnumerable<OutputRecord> output = input
        .GroupBy(r => new { r.name, r.state })
        .Where(g => g.Any(r => r.childGender == 'M') && g.Any(r => r.childGender == 'F'))
        .Select(g => new OutputRecord
        {
            name = g.Key.name,
            state = g.Key.state,
            ClosetSize = g.Sum(r => r.ClosetSize),
        });
    
    OutputRecord.SaveTo(outputFile, output);
}

Output:

name,state,ClosetSize
Hank,OK,3
Zed,VT,6