Skip to main content

Tabular v1.0 - Import/Export Tabular Data to Excel and CSV

Awhile ago, I wrote a small library for describing, importing, and exporting tabular data to and from Excel XML, and CSV formats. I just never got around to releasing it, but I'm making a more concerted effort recently to push releases forward. The full documentation is online, and the binaries here. The license is LGPL.

Describing Tabular Data

Tabular.dll is an assembly via which you can declaratively describe tabular data:

var table1 = new Table
{
    Name = "SomeTable",
    Rows =
    {
        new Row { 1, "foo", 5.7 },
        new Row { 2, "bar", 99.99M },
        new Row { 3, "baz", 0.0 },
    }
};

There are really only three classes of interest, Table, Row, and Cell. A table consists of a series of rows, a row consists of a series of cells, and each cell consists of a string value together with an alleged data type describing the string contents.

The DataType enumeration is the list of recognized data strings. Cell provides numerous implicit coercions from CLR types to Cell and sets the appropriate data type, so declarative tables are simple to describe as the above code sample demonstrates.

It's also quite simple to describe a table that's derive from some enumerable source:

IEnumerable list = ...
var table = new Table
{
    Name = "EnumerableTable",
    Bind = list.Select((x,i) => new Row { i, x })
}

You can also imperatively build up the table using the AddRow method.

Import/Export of CSV Data

Tabular.Csv.dll provides import and export of tabular data to CSV format:

var table1 = new Table
{
    Name = "SomeTable",
    Rows =
    {
        new Row { 1, "foo", 5.7 },
        new Row { 2, "bar", 99.99M },
        new Row { 3, "baz", 0.0 },
    }
};
var csv = Csv.ToCsv(table1, CsvFormat.Quoted);
Console.WriteLine(csv.Data);

// output:
// "1","foo","5.7"
// "2","bar","99.99"
// "3","baz","0"

var table2 = Csv.FromCsv(csv);
// table2 is equivalent to table1

The CsvFormat enumeration describes whether the CSV data should be formatted in the safer quoted data format, or in the less safe raw format.

Import/Export of Excel Data

Tabular.Excel.dll provide import and export features for Excel XML file format. Excel 2002 XML schema is used for simplicity. See the docs for the full details, but here's a relatively straightforward overview:

var table1 = new Table
{
    Name = "SomeTable",
    Rows =
    {
        new Row { 1, "foo", 5.7 },
        new Row { 2, "bar", 99.99M },
        new Row { 3, "baz", 0.0 },
    }
};
// generate in-memory XDocument that you can work with
XDocument excel = Excel.ToXml(table1);

// or write directly to stream
using (var stream = File.OpenWrite("foo.xml"))
{
    Excel.WriteTo(table1, stream);
}

// you can also import the xml data
Table table2 = Excel.FromXml(excel);

// or import by reading from a stream
using (var stream = File.OpenRead("foo.xml"))
{
    table2 = Excel.ReadFrom(stream);
}

Edit: just an update, I've uploaded the Tabular v1.0 release to NuGet.

Comments

Popular posts from this blog

async.h - asynchronous, stackless subroutines in C

The async/await idiom is becoming increasingly popular. The first widely used language to include it was C#, and it has now spread into JavaScript and Rust. Now C/C++ programmers don't have to feel left out, because async.h is a header-only library that brings async/await to C! Features: It's 100% portable C. It requires very little state (2 bytes). It's not dependent on an OS. It's a bit simpler to understand than protothreads because the async state is caller-saved rather than callee-saved. #include "async.h" struct async pt; struct timer timer; async example(struct async *pt) { async_begin(pt); while(1) { if(initiate_io()) { timer_start(&timer); await(io_completed() || timer_expired(&timer)); read_data(); } } async_end; } This library is basically a modified version of the idioms found in the Protothreads library by Adam Dunkels, so it's not truly ground bre

Building a Query DSL in C#

I recently built a REST API prototype where one of the endpoints accepted a string representing a filter to apply to a set of results. For instance, for entities with named properties "Foo" and "Bar", a string like "(Foo = 'some string') or (Bar > 99)" would filter out the results where either Bar is less than or equal to 99, or Foo is not "some string". This would translate pretty straightforwardly into a SQL query, but as a masochist I was set on using Google Datastore as the backend, which unfortunately has a limited filtering API : It does not support disjunctions, ie. "OR" clauses. It does not support filtering using inequalities on more than one property. It does not support a not-equal operation. So in this post, I will describe the design which achieves the following goals: A backend-agnostic querying API supporting arbitrary clauses, conjunctions ("AND"), and disjunctions ("OR"). Implemen

Easy Automatic Differentiation in C#

I've recently been researching optimization and automatic differentiation (AD) , and decided to take a crack at distilling its essence in C#. Note that automatic differentiation (AD) is different than numerical differentiation . Math.NET already provides excellent support for numerical differentiation . C# doesn't seem to have many options for automatic differentiation, consisting mainly of an F# library with an interop layer, or paid libraries . Neither of these are suitable for learning how AD works. So here's a simple C# implementation of AD that relies on only two things: C#'s operator overloading, and arrays to represent the derivatives, which I think makes it pretty easy to understand. It's not particularly efficient, but it's simple! See the "Optimizations" section at the end if you want a very efficient specialization of this technique. What is Automatic Differentiation? Simply put, automatic differentiation is a technique for calcu