csv-writer
Advanced tools
Convert objects/arrays into a CSV string or write them into a file. It respects RFC 4180 for the output CSV format.
The example below shows how you can write records defined as the array of objects into a file.
const createCsvWriter = require('csv-writer').createObjectCsvWriter;
const csvWriter = createCsvWriter({
path: 'path/to/file.csv',
header: [
{id: 'name', title: 'NAME'},
{id: 'lang', title: 'LANGUAGE'}
]
});
const records = [
{name: 'Bob', lang: 'French, English'},
{name: 'Mary', lang: 'English'}
];
csvWriter.writeRecords(records) // returns a promise
.then(() => {
console.log('...Done');
});
// This will produce a file path/to/file.csv with following contents:
//
// NAME,LANGUAGE
// Bob,"French, English"
// Mary,English
You can keep writing records into the same file by calling writeRecords multiple times
(but need to wait for the fulfillment of the promise of the previous writeRecords call).
// In an `async` function
await csvWriter.writeRecords(records1)
await csvWriter.writeRecords(records2)
...
However, if you need to keep writing large data to a certain file, you would want to create
node's transform stream and use CsvStringifier, which is explained later, inside it
, and pipe the stream into a file write stream.
If you don't want to write a header line, don't give title to header elements and just give field IDs as a string.
const createCsvWriter = require('csv-writer').createObjectCsvWriter;
const csvWriter = createCsvWriter({
path: 'path/to/file.csv',
header: ['name', 'lang']
});
If each record is defined as an array, use createArrayCsvWriter to get an csvWriter.
const createCsvWriter = require('csv-writer').createArrayCsvWriter;
const csvWriter = createCsvWriter({
header: ['NAME', 'LANGUAGE'],
path: 'path/to/file.csv'
});
const records = [
['Bob', 'French, English'],
['Mary', 'English']
];
csvWriter.writeRecords(records) // returns a promise
.then(() => {
console.log('...Done');
});
// This will produce a file path/to/file.csv with following contents:
//
// NAME,LANGUAGE
// Bob,"French, English"
// Mary,English
If you just want to get a CSV string but don't want to write into a file,
you can use createObjectCsvStringifier (or createArrayCsvStringifier)
to get an csvStringifier.
const createCsvStringifier = require('csv-writer').createObjectCsvStringifier;
const csvStringifier = createCsvStringifier({
header: [
{id: 'name', title: 'NAME'},
{id: 'lang', title: 'LANGUAGE'}
]
});
const records = [
{name: 'Bob', lang: 'French, English'},
{name: 'Mary', lang: 'English'}
];
console.log(csvStringifier.getHeaderString());
// => 'NAME,LANGUAGE\n'
console.log(csvStringifier.stringifyRecords(records));
// => 'Bob,"French, English"\nMary,English\n'
<Object>
path <string>
Path to a write file
header <Array<{id, title}|string>>
Array of objects (id and title properties) or strings (field IDs).
A header line will be written to the file only if given as an array of objects.
fieldDelimiter <string> (optional)
Default: ,. Only either comma , or semicolon ; is allowed.
recordDelimiter <string> (optional)
Default: \n. Only either LF (\n) or CRLF (\r\n) is allowed.
headerIdDelimiter <string> (optional)
Default: undefined. Give this value to specify a path to a value in a nested object.
alwaysQuote <boolean> (optional)
Default: false. Set it to true to double-quote all fields regardless of their values.
encoding <string> (optional)
Default: utf8.
append <boolean> (optional)
Default: false. When true, it will append CSV records to the specified file.
If the file doesn't exist, it will create one.
NOTE: A header line will not be written to the file if true is given.
<CsvWriter><Object>
path <string>
Path to a write file
header <Array<string>> (optional)
Array of field titles
fieldDelimiter <string> (optional)
Default: ,. Only either comma , or semicolon ; is allowed.
recordDelimiter <string> (optional)
Default: \n. Only either LF (\n) or CRLF (\r\n) is allowed.
alwaysQuote <boolean> (optional)
Default: false. Set it to true to double-quote all fields regardless of their values.
encoding <string> (optional)
Default: utf8.
append <boolean> (optional)
Default: false. When true, it will append CSV records to the specified file.
If the file doesn't exist, it will create one.
NOTE: A header line will not be written to the file if true is given.
<CsvWriter>records <Iterator<Object|Array>>
Depending on which function was used to create a csvWriter (i.e. createObjectCsvWriter or createArrayCsvWriter),
records will be either a collection of objects or arrays. As long as the collection is iterable, it doesn't need to be an array.
<Promise><Object>
header <Array<{id, title}|string>>
Array of objects (id and title properties) or strings (field IDs)
fieldDelimiter <string> (optional)
Default: ,. Only either comma , or semicolon ; is allowed.
recordDelimiter <string> (optional)
Default: \n. Only either LF (\n) or CRLF (\r\n) is allowed.
headerIdDelimiter <string> (optional)
Default: undefined. Give this value to specify a path to a value in a nested object.
alwaysQuote <boolean> (optional)
Default: false. Set it to true to double-quote all fields regardless of their values.
<ObjectCsvStringifier><string><Array<Object>><string><Object>
header <Array<string>> (optional)
Array of field titles
fieldDelimiter <string> (optional)
Default: ,. Only either comma , or semicolon ; is allowed.
recordDelimiter <string> (optional)
Default: \n. Only either LF (\n) or CRLF (\r\n) is allowed.
alwaysQuote <boolean> (optional)
Default: false. Set it to true to double-quote all fields regardless of their values.
<ArrayCsvStringifier><string><Array<Array<string>>><string>Feature requests and bug reports are very welcome: https://github.com/ryu1kn/csv-writer/issues
A couple of requests from me when you raise an issue on GitHub.
fast-csv is a comprehensive library for parsing and formatting CSVs in Node.js. It offers a wide range of features including streaming, custom formatting, and support for various CSV dialects. Compared to csv-writer, fast-csv provides more advanced parsing capabilities and is suitable for handling large datasets efficiently.
csv-parser is a simple and efficient library for parsing CSV files in Node.js. It is designed to be fast and easy to use, with a focus on performance. While csv-parser is primarily focused on reading CSV files, it can be used in conjunction with other libraries to write CSV files. It is a good choice for applications that require high-speed CSV parsing.
papaparse is a powerful CSV parser that works in both Node.js and the browser. It supports a wide range of features including streaming, custom delimiters, and error handling. While papaparse is primarily known for its parsing capabilities, it also includes functionality for writing CSV files. It is a versatile library that can handle various CSV-related tasks.
FAQs
Convert objects/arrays into a CSV string or write them into a CSV file
The npm package csv-writer receives a total of 1,263,758 weekly downloads. As such, csv-writer popularity was classified as popular.
We found that csv-writer demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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