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CLI arguments parser for node.js, with sub-commands support. Port of python's argparse (version 3.9.0).

Difference with original.

  • JS has no keyword arguments support.
    • Pass options instead: new ArgumentParser({ description: 'example', add_help: true }).
  • JS has no python's types int, float, ...
    • Use string-typed names: .add_argument('-b', { type: 'int', help: 'help' }).
  • %r format specifier uses require('util').inspect().

More details in doc.


test.js file:

#!/usr/bin/env node
'use strict';

const { ArgumentParser } = require('argparse');
const { version } = require('./package.json');

// Formatter with support of `\n` in Help texts.
class HelpFormatter extends ArgumentParser.RawDescriptionHelpFormatter {
  // executes parent _split_lines for each line of the help, then flattens the result
  _split_lines(text, width) {
    return [].concat(...text.split('\n').map(line => super._split_lines(line, width)));

const parser = new ArgumentParser({
  description: 'Argparse example',
  add_help: true,
  formatter_class: HelpFormatter

parser.add_argument('-v', '--version', { action: 'version', version });
parser.add_argument('-f', '--foo', { help: 'foo bar' });
parser.add_argument('-b', '--bar', { help: 'bar foo' });
parser.add_argument('--baz', { help: 'baz bar' });


Display help:

$ ./test.js -h
usage: test.js [-h] [-v] [-f FOO] [-b BAR] [--baz BAZ]

Argparse example

optional arguments:
  -h, --help         show this help message and exit
  -v, --version      show program's version number and exit
  -f FOO, --foo FOO  foo bar
  -b BAR, --bar BAR  bar foo
  --baz BAZ          baz bar

Parse arguments:

$ ./test.js -f=3 --bar=4 --baz 5
{ foo: '3', bar: '4', baz: '5' }

API docs

Since this is a port with minimal divergence, there's no separate documentation. Use original one instead, with notes about difference.

  1. Original doc.
  2. Original tutorial.
  3. Difference with python.

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CLI arguments parser for node.js. JS port of python's argparse module.



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