csv-parse/README.md

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

# CSV parser for Node.js and the web

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The [`csv-parse` package](https://csv.js.org/parse/) is a parser converting CSV text input into arrays or objects. It is part of the [CSV project](https://csv.js.org/).

It implements the Node.js [`stream.Transform` API](http://nodejs.org/api/stream.html#stream_class_stream_transform). It also provides a simple callback-based API for convenience. It is both extremely easy to use and powerful. It was first released in 2010 and is used against big data sets by a large community.

## Documentation

* [Project homepage](https://csv.js.org/parse/)
* [API](https://csv.js.org/parse/api/)
* [Options](https://csv.js.org/parse/options/)
* [Info properties](https://csv.js.org/parse/info/)
* [Common errors](https://csv.js.org/parse/errors/)
* [Examples](https://csv.js.org/project/examples/)

## Main features

*   Flexible with lot of [options](https://csv.js.org/parse/options/)
*   Multiple [distributions](https://csv.js.org/parse/distributions/): Node.js, Web, ECMAScript modules and CommonJS
*   Follow the Node.js streaming API
*   Simplicity with the optional callback API
*   Support delimiters, quotes, escape characters and comments
*   Line breaks discovery
*   Support big datasets
*   Complete test coverage and lot of samples for inspiration
*   No external dependencies
*   Work nicely with the [csv-generate](https://csv.js.org/generate/), [stream-transform](https://csv.js.org/transform/) and [csv-stringify](https://csv.js.org/stringify/) packages
*   MIT License

## 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 and sync APIs for simplicity or the stream based API for scalability.

## Example

The [API](https://csv.js.org/parse/api/) is available in multiple flavors. This example illustrates the stream API.

```js
import assert from 'assert';
import { parse } from 'csv-parse';

const records = [];
// Initialize the parser
const parser = parse({
  delimiter: ':'
});
// Use the readable stream api to consume records
parser.on('readable', function(){
  let record;
  while ((record = parser.read()) !== null) {
    records.push(record);
  }
});
// Catch any error
parser.on('error', function(err){
  console.error(err.message);
});
// Test that the parsed records matched the expected records
parser.on('end', function(){
  assert.deepStrictEqual(
    records,
    [
      [ 'root','x','0','0','root','/root','/bin/bash' ],
      [ 'someone','x','1022','1022','','/home/someone','/bin/bash' ]
    ]
  );
});
// Write data to the stream
parser.write("root:x:0:0:root:/root:/bin/bash\n");
parser.write("someone:x:1022:1022::/home/someone:/bin/bash\n");
// Close the readable stream
parser.end();
```

## Contributors

The project is sponsored by [Adaltas](https://www.adaltas.com), an Big Data consulting firm based in Paris, France.

*   David Worms: <https://github.com/wdavidw>