👉 This library is outdated
- lacks of DateTime type, etc.
- consider CsvHelper project as a better alternative
.NET core CSV
- create console project
dotnet new console -n example
cd example- add reference to netcore-sci ( check latest version here )
dotnet add package netcore-csv --version 0.1.0if prefer to link source code directly to stepin with debugger add project reference instead
dotnet add reference path_to/netcore-csv/netcore-csv.csprojfor some useful sci extensions include netcore-sci
dotnet add package netcore-sci --version 1.26.0
-
setup example code ( see examples )
- example-01 : first csv program
- example-02 : linq to csv
- example-03 : sci data
- reader requires a class type to describe field types
- writer can work directly from anonymous type ( see example02 )
- colum header can be overriden using
CsvHeaderproperty ( see example3 )
using SearchAThing.CSV;
using System.Linq;
using System.IO;
namespace example_01
{
public enum TestEnum
{
unknown,
enumA,
enumB
}
public class MyData
{
public int intNr { get; set; }
public string name { get; set; }
public double val { get; set; }
public TestEnum enumVal { get; set; }
}
class Program
{
static void Main(string[] args)
{
var pathfilename = "output.csv";
using (var csv = new CsvWriter<MyData>(pathfilename))
{
csv.Push(new MyData
{
intNr = 10,
name = "name1",
val = 11.2,
enumVal = TestEnum.enumA
});
csv.Push(new MyData
{
intNr = 25,
name = "name2",
val = 13.4,
enumVal = TestEnum.enumB
});
}
// append more
using (var csv = new CsvWriter<MyData>(pathfilename, true))
{
csv.Push(new MyData
{
intNr = 30,
name = "name3",
val = 44.5
});
csv.Push(new MyData
{
intNr = 35,
name = "name4",
val = 33.2
});
}
// read back data
System.Console.WriteLine(File.ReadAllText(pathfilename));
var q = new CsvReader<MyData>(pathfilename)
.GroupBy(w => w.enumVal)
.Select(w => new
{
enType = w.Key,
sum = w.Sum(y => y.val),
});
foreach (var x in q)
{
System.Console.WriteLine($"enum:{x.enType} sum:{x.sum}");
}
}
}
}- output
"intNr","name","val","enumVal"
10,"name1",11.2,"enumA"
25,"name2",13.4,"enumB"
30,"name3",44.5,"unknown"
35,"name4",33.2,"unknown"
enum:enumA sum:11.2
enum:enumB sum:13.4
enum:unknown sum:77.7
using System.IO;
using System.Linq;
using SearchAThing;
namespace example_02
{
class Program
{
static void Main(string[] args)
{
var pathfilename = "output.csv";
new[] { 1, 2, 3 }.Select(w => new
{
str = $"string with val={w}",
val = w
}).ToCSV(pathfilename, new SearchAThing.CSV.CsvOptions()
{
PropNameToHeaderFunc = (propName) =>
{
switch (propName)
{
case "val": return "Value";
}
return null;
}
});
System.Console.WriteLine(File.ReadAllText(pathfilename));
}
}
}output
"str","Value"
"string with val=1",1
"string with val=2",2
"string with val=3",3
using System;
using System.Linq;
using SearchAThing;
using System.Diagnostics;
using SearchAThing.CSV;
using System.Collections.Generic;
namespace test
{
public enum TestEnum
{
atype,
btype,
}
public class MyData
{
public int i10 { get; set; }
public int i20 { get; set; }
[CsvHeader("SomeStringCol")]
public string s1 { get; set; }
[CsvHeader("FirstDblCol")]
public double v1 { get; set; }
public double v2 { get; set; }
public double v3 { get; set; }
public double v4 { get; set; }
public double v5 { get; set; }
public double v6 { get; set; }
public double v7 { get; set; }
public double v8 { get; set; }
public double v9 { get; set; }
public double v10 { get; set; }
public double v11 { get; set; }
public double v12 { get; set; }
public double v13 { get; set; }
public double v14 { get; set; }
public double v15 { get; set; }
public double v16 { get; set; }
public double v17 { get; set; }
public double v18 { get; set; }
public double v19 { get; set; }
public double v20 { get; set; }
[CsvColumnOrder(0)]
public double firstcol { get; set; }
public TestEnum envar { get; set; }
}
class Program
{
static void Main(string[] args)
{
const int CNT = 500000;
{
var stopw = new Stopwatch();
stopw.Start();
// <LangVersion>8.0</LangVersion>
using var csv = new CsvWriter<MyData>("test.csv");
var rnd = new Random();
for (int i = 0; i < CNT; ++i)
{
var d = new MyData
{
v1 = rnd.NextDouble() * 1e9,
v2 = rnd.NextDouble() * 1e9,
v3 = rnd.NextDouble() * 1e9,
v4 = rnd.NextDouble() * 1e9,
v5 = rnd.NextDouble() * 1e9,
v6 = rnd.NextDouble() * 1e9,
v7 = rnd.NextDouble() * 1e9,
v8 = rnd.NextDouble() * 1e9,
v9 = rnd.NextDouble() * 1e9,
v10 = rnd.NextDouble() * 1e9,
v11 = rnd.NextDouble() * 1e9,
v12 = rnd.NextDouble() * 1e9,
v13 = rnd.NextDouble() * 1e9,
v14 = rnd.NextDouble() * 1e9,
v15 = rnd.NextDouble() * 1e9,
v16 = rnd.NextDouble() * 1e9,
v17 = rnd.NextDouble() * 1e9,
v18 = rnd.NextDouble() * 1e9,
v19 = rnd.NextDouble() * 1e9,
v20 = rnd.NextDouble() * 1e9,
i10 = rnd.Next(1, 10),
i20 = rnd.Next(1, 20),
s1 = $"str:[{rnd.Next()}]",
envar = TestEnum.atype,
};
csv.Push(d);
}
System.Console.WriteLine($"written [{CNT}] rows in {stopw.Elapsed}");
}
{
var stopw = new Stopwatch();
stopw.Start();
using var csv = new CsvReader<MyData>("test.csv");
// optional custom header
var customHeader = new Dictionary<string, string>();
customHeader.Add("v3Mean", "v3Mean (Custom)");
csv
.GroupBy(w => w.i10)
.Select(w => new
{
i10 = w.Key,
i20Min = w.Min(r => r.i20),
i20Max = w.Max(r => r.i20),
v1Mean = w.Select(w => w.v1).Mean(),
v2Mean = w.Select(w => w.v2).Mean(),
v3Mean = w.Select(w => w.v3).Mean(),
v4Mean = w.Select(w => w.v4).Mean(),
v5Mean = w.Select(w => w.v5).Mean(),
v6Mean = w.Select(w => w.v6).Mean(),
v7Mean = w.Select(w => w.v7).Mean(),
v8Mean = w.Select(w => w.v8).Mean(),
v9Mean = w.Select(w => w.v9).Mean(),
v10Mean = w.Select(w => w.v10).Mean(),
v11Mean = w.Select(w => w.v11).Mean(),
v12Mean = w.Select(w => w.v12).Mean(),
v13Mean = w.Select(w => w.v13).Mean(),
v14Mean = w.Select(w => w.v14).Mean(),
v15Mean = w.Select(w => w.v15).Mean(),
v16Mean = w.Select(w => w.v16).Mean(),
v17Mean = w.Select(w => w.v17).Mean(),
v18Mean = w.Select(w => w.v18).Mean(),
v20Mean = w.Select(w => w.v20).Mean(),
}).ToCSV("result.csv",
new CsvOptions() // optional
{
PropNameHeaderMapping = customHeader,
PropNameToHeaderFunc = (propname) =>
// <LangVersion>8.0</LangVersion>
propname switch
{
"v4Mean" => "v4Mean (Custom)",
_ => null,
}
});
System.Console.WriteLine($"queried [{CNT}] rows in {stopw.Elapsed}");
}
}
}
}- output
devel0@main:/opensource/devel0/netcore-csv$ dotnet run -p examples/example-03
written [500000] rows in 00:00:17.7151366
queried [500000] rows in 00:00:13.8399370- generated input data sample
devel0@main:/opensource/devel0/netcore-csv/example$ head -n 3 test.csv
"firstcol","i10","i20","SomeStringCol","FirstDblCol","v2","v3","v4","v5","v6","v7","v8","v9","v10","v11","v12","v13","v14","v15","v16","v17","v18","v19","v20"
0,5,12,"str:[18129689]",867557696.4707849,109447404.32754503,62481810.83355183,10286359.12122501,16821376.52152282,246951585.75053865,40531692.57963621,128706280.20200239,94060354.9098877,773084326.5415562,605406319.0731249,24301973.182848644,275546743.6628168,993341022.6336405,332197053.51265013,897891412.4415683,393898102.63826424,75625031.75606254,141746737.59459832,923235933.7262976
0,7,8,"str:[715246488]",778737590.5452006,746023428.9737527,143709297.35885435,259873150.9688651,974400662.8051404,228502796.13793957,726555496.7925677,918882383.9271824,937200791.1732424,243253674.4714033,217995068.1598834,805125237.3518074,83740469.57294479,305738162.85735846,624054313.9279143,934975130.9188899,116701281.68384604,279470807.5371901,296962312.5609766,391285082.04188436- generated linq query over input data
devel0@main:/opensource/devel0/netcore-csv/example$ head -n 3 result.csv
"i10","i20Min","i20Max","v1Mean","v2Mean","v3Mean","v4Mean","v5Mean","v6Mean","v7Mean","v8Mean","v9Mean","v10Mean","v11Mean","v12Mean","v13Mean","v14Mean","v15Mean","v16Mean","v17Mean","v18Mean","v20Mean"
5,1,19,498744375.0046595,500696328.76969767,498956994.79407644,498347553.3321365,499105076.1419511,497968869.1339944,501762405.8354361,499745779.22874564,500889471.2232371,500183490.45615464,499631274.71673,499687046.22139966,500878450.76341426,499645752.7216835,501762614.12378675,500649710.9467961,501233924.9635705,498505682.329863,499466519.5720193
7,1,19,500261473.80103374,499153526.46980953,499105413.8423311,498641774.89563894,500344995.4115497,499545597.67373264,501381194.974964,499761652.26916814,500232888.6299126,500631700.19801253,500045648.5480878,502821365.214899,500142713.6305659,499689342.6614191,498776087.82817686,498683736.7473624,498262792.1616414,500554332.6785145,500256673.0652077test.csvis the input data createdresult.csvis a linq query over that data
to exclude some property from being serialized to/from csv use CsvIgnore attribute
- thread safe support on write
mkdir netcore-csv
cd netcore-csv
dotnet new sln
dotnet new classlib -n netcore-csv
dotnet new console -n examples
cd netcore-csv
dotnet add package netcore-util --version 1.0.6
cd ..
mkdir examples
cd examples
for i in 01 02 03; do
dotnet new console -n example-$i
cd example-$i
dotnet add reference ../../netcore-csv
cd ..
done
cd ..
dotnet sln netcore-csv.sln add netcore-csv
for i in 01 02 03; do dotnet sln netcore-csv.sln add examples/example-$i; done
dotnet build