csv-stringify

What is csv-stringify?

The csv-stringify npm package is a module that provides the ability to convert arrays or objects into a CSV (Comma-Separated Values) string. It can be used to generate CSV files or strings from JavaScript data structures, supporting both the Node.js stream API and a simple callback-based API.

What are csv-stringify's main functionalities?

Stringifying an array of records

This feature allows you to convert an array of arrays (representing records) into a CSV string. Each sub-array is a row in the CSV output.

const stringify = require('csv-stringify');
const records = [['1', '2', '3'], ['a', 'b', 'c']];
stringify(records, (err, output) => {
  if (err) throw err;
  console.log(output);
});

Stringifying from a stream

This feature demonstrates how to use csv-stringify with Node.js streams. Data can be piped into the stringify function, which then outputs a CSV formatted stream.

const stringify = require('csv-stringify');
const { Readable } = require('stream');
const records = new Readable({
  objectMode: true,
  read() {}
});
records.push(['1', '2', '3']);
records.push(['a', 'b', 'c']);
records.push(null);
records.pipe(stringify()).pipe(process.stdout);

Stringifying objects with column headers

This feature allows you to convert an array of objects into a CSV string, including column headers as the first row in the output.

const stringify = require('csv-stringify');
const records = [{ id: '1', name: 'John Doe' }, { id: '2', name: 'Jane Doe' }];
stringify(records, { header: true }, (err, output) => {
  if (err) throw err;
  console.log(output);
});

Other packages similar to csv-stringify

papaparse

PapaParse is a robust and powerful CSV (character-separated values) parser with a focus on ease of use and performance. It can parse CSV files or strings, convert them to JSON, and provide many advanced features like auto-detection of delimiters. Compared to csv-stringify, PapaParse offers both parsing and stringifying capabilities, whereas csv-stringify is focused only on stringifying.

fast-csv

fast-csv is an npm package that provides parsing and formatting capabilities for CSV data. It is designed to be fast and flexible, allowing for both stream and callback-based APIs. While csv-stringify is specifically for stringifying JavaScript data into CSV format, fast-csv offers both parsing and formatting, making it a more comprehensive solution for working with CSV data.

README

This project is part of the CSV module and a stringifier converting records into a CSV text and implementing the Node.js stream.Transform API. It is also providing a simple callback-base API for converniency. It is both extremely easy to use and powerfull. It was released since 2010 and is tested against very large dataset by a large community.

Documentation for the "csv-stringify" package is available here.

Note

This module is to be considered in alpha stage. It is part of an ongoing effort to split the current CSV module into complementary modules with a cleaner design and the latest stream implementation. However, the code has been imported with very little changes and you should feel confident to use it in your code.

Usage

Run npm install csv to install the full csv module or run npm install csv-stringify if you are only interested by the CSV stringifier.

Use the callback style API for simplicity or the stream based API for scalability.

Using the callback API

The stringifier receive an array and return a string inside a user-provided callback. This example is available with the command node samples/callback.js.

var stringify = require('csv-stringify');

input = [ [ '1', '2', '3', '4' ], [ 'a', 'b', 'c', 'd' ] ];
stringify(input, function(err, output){
  output.should.eql('1,2,3,4\na,b,c,d');
});

Using the stream API

// node samples/stream.js
var stringify = require('csv-stringify');

data = '';
stringifier = stringify({delimiter: ':'})
stringifier.on('readable', function(){
  while(row = stringifier.read()){
    data += row;
  }
});
stringifier.on('error', function(err){
  consol.log(err.message);
});
stringifier.on('finish', function(){
  data.should.eql(
    "root:x:0:0:root:/root:/bin/bash\n" +
    "someone:x:1022:1022:a funny cat:/home/someone:/bin/bash"
  );
});
stringifier.write([ 'root','x','0','0','root','/root','/bin/bash' ]);
stringifier.write([ 'someone','x','1022','1022','a funny cat','/home/someone','/bin/bash' ]);
stringifier.end();

Using the pipe function

One usefull function part of the Stream API is pipe to interact between multiple streams. You may use this function to pipe a stream.Readable array or object source to a stream.Writable string destination. The next example available as node samples/pipe.js generate records, stringify them and print them to stdout.

stringify = require('csv-stringify');
generate = require('csv-generate');

generator = generate({objectMode: true, seed: 1, headers: 2});
stringifier = stringify();
generator.pipe(stringifier).pipe(process.stdout);

Migration

Most of the generator is imported from its parent project CSV in a effort to split it between the generator, the parser, the transformer and the stringifier.

Development

Tests are executed with mocha. To install it, simple run npm install followed by npm test. It will install mocha and its dependencies in your project "node_modules" directory and run the test suite. The tests run against the CoffeeScript source files.

To generate the JavaScript files, run make build.

The test suite is run online with Travis against the versions 0.9, 0.10 and 0.11 of Node.js.

Contributors

• David Worms: https://github.com/wdavidw