Transform CSV stream
npm install csv-stream-transformNode.js module for stream transforming CSV.
Just a thin wrapper around csv-parse, csv-stringify, and a Node.js
transform stream.
``
npm i csv-stream-transform
The following command will clone joe and nancy, make them much more important,
10 years younger, and change the tab separated file to a comma separated file.
`
./transform.js < in.tsv > out.csv
./transform.js
`
#!/usr/bin/env node
'use strict';
// This is just an example file to show you how to use csv-stream-transform.
require('csv-stream-transform')({
transform(row, cb) {
const o = {};
o.Name = row.person.toUpperCase();
o.Age = row.age - 10;
this.push(o);
this.push(o);
cb(null);
},
// flush is optional.
// defaults to no-op.
flush(cb) {
cb();
},
// parse is optional.
// defaults to { columns: true }
// See http://csv.adaltas.com/parse for all options.
parse: {
delimiter: '\t'
},
// stringify is optional.
// defaults to { header: true }
// See http://csv.adaltas.com/stringify for all options.
stringify: {
// delimiter: ','
},
// in is optional.
// defaults to process.stdin
in: process.stdin,
// out is optional.
// defaults to process.stdout
// if out === 'NOOUT' we stop after transform and don't pipe to out.
out: process.stdout,
// finish defaults to a no-op function.
// if you want something to happen on finish you can
// include it here.
finish: () => { console.error('we are finished'); }
});
`
in.tsv
`
person
joe smith
nancy foo
out.csv
`
Name,Age
JOE SMITH,27
JOE SMITH,27
NANCY FOO,88
NANCY FOO,88