csv-parse

CSV parsing implementing the Node.js `stream.Transform` API

npm install csv-parse
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Build Status

This project is part of the CSV module and is a parser converting input CSV text into arrays or objects 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.

The full documentation of the CSV parser 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-parse if you are only interested by the CSV parser.

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

Using the callback API

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

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

input = '#Welcome\n"1","2","3","4"\n"a","b","c","d"';
parse(input, {comment: '#'}, function(err, output){
  output.should.eql([ [ '1', '2', '3', '4' ], [ 'a', 'b', 'c', 'd' ] ]);
});

Using the stream API

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

output = [];
parser = parse({delimiter: ':'})
parser.on('readable', function(){
  while(row = parser.read()){
    output.push(row)
  }
});
parser.on('error', function(err){
  consol.log(err.message);
});
parser.on('finish', function(){
  output.should.eql([
    [ 'root','x','0','0','root','/root','/bin/bash' ],
    [ 'someone','x','1022','1022','a funny cat','/home/someone','/bin/bash' ]
  ]);
});
parser.write("root:x:0:0:root:/root:/bin/bash\n");
parser.write("someone:x:1022:1022:a funny cat:/home/someone:/bin/bash\n");
parser.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 string source to a stream.Writable object destination. The next example available as node samples/pipe.js read the file, parse its content and transform it.

output = [];
parser = parse({delimiter: ':'})
input = fs.createReadStream('/etc/passwd');
transformer = transform(function(row, callback){
  setTimeout(function(){
    callback(null, row.join(' ')+'\n');
  }, 500);
}, {parallel: 10});
input.pipe(parser).pipe(transformer).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

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