How to read csv file in node js

Question

I am trying to read a csv file using node js. Her is my code

fs.readFile(config.csvUploadPath, function read(err, data) {
    if (err) {
        throw err;
    }
    console.log(data + 'my data')
});

CONSOLE:

ID
D11
D33
D55

Here I want to get the elements in the column ID and store those in an array. How can I do that? Can anyone suggest me help. Thanks. My controller:

var partnersModel = new partners(params);
        fs.readFile(config.csvUploadPath, function read(err, data) {
            if (err) {
                throw err;
            }
        dataArray = data.toString().split(/\r?\n/);
            dataArray.forEach(function(v,i){
                if(v !== 'DUI'){
                  partnersModel.dui.push(v);
                }
            });
        });
        partnersModel.save(function(error, response){

stackoverflow.com/questions/23080413/nodejs-reading-csv-file — Himesh Suthar
– Himesh Suthar, Commented Jan 21, 2017 at 7:52
Is this actually a CSV file, or just a file containing a list of IDs? This would be pretty easy to parse without a library, but if you are parsing true CSV definitely use one! My module of choice is: npmjs.com/package/csv — le3th4x0rbot
– le3th4x0rbot, Commented Jan 21, 2017 at 8:06
Hi.Bailsey ihave only one column name ID and want to store all the values of it in an array. — MMR
– MMR, Commented Jan 21, 2017 at 8:08
This is not really CSV then, it is just a file with data on each row. You could use data.split('\n') [developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…. It would return an array like you desire. — le3th4x0rbot
– le3th4x0rbot, Commented Jan 21, 2017 at 8:28

Mat · Accepted Answer · 2017-07-29 19:58:51Z

56

Use a library, CSV has lots of gotchas. I have come to enjoy the package csv. It is located here: https://www.npmjs.com/package/csv . Here is a very quick example using the async api.

const fs = require('fs')
var parse = require('csv-parse')
fs.readFile(inputPath, function (err, fileData) {
  parse(fileData, {columns: false, trim: true}, function(err, rows) {
    // Your CSV data is in an array of arrys passed to this callback as rows.
  })
})

Since your file does not have multiple values per row and contains no delimiters besides newline, it is only trivially CSV. Maybe String.prototype.split() is for you?

const fs = require('fs')
fs.readFile(inputPath, 'utf8', function (err, data) {
  var dataArray = data.split(/\r?\n/);  //Be careful if you are in a \r\n world...
  // Your array contains ['ID', 'D11', ... ]
})

edited Jul 29, 2017 at 19:58

Mat

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answered Jan 21, 2017 at 8:14

le3th4x0rbot

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7 Comments

le3th4x0rbot Over a year ago

CSV files typically have multiple values per row, so it returns an array of arrays... one for each row. For your example rows= [ ['id'], ['D11'], ['D33'], ['D55'] ]. Note that the header was parsed too, and that to index one of the values you would need to use something like rows[1][0].

le3th4x0rbot Over a year ago

There are options about header handling, and the library can help you stuff the values into objects for each row with properties matching the column names. TFM is located here: csv.adaltas.com/parse

MMR Over a year ago

But i am getting the error' data.split is not a function'

le3th4x0rbot Over a year ago

I thought readFile always passed a string as data, but apparently it only does if you specify an encoding. The example has been updated!

MMR Over a year ago

i got it by this... dataArray = data.toString().split(/\r?\n/);

|

ehacinom · Accepted Answer · 2019-08-23 22:12:40Z

19

I used a stream, fs, and csv-parse like in this answer:

const parse = require('csv-parse')
const fs = require('fs') 

const data = []
fs.createReadStream(filename)
  .pipe(parse({ delimiter: ',' }))
  .on('data', (r) => {
    console.log(r);
    data.push(r);        
  })
  .on('end', () => {
    console.log(data);
  })

answered Aug 23, 2019 at 22:12

ehacinom

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3 Comments

user9629064 Over a year ago

How do I access the data in the array? for some reason (i think it because of the async nature of createReadStream) the array lentght equals 0, when I try to check it

Kyle Pennell Over a year ago

parse is not defined.

timlg07 Over a year ago

@KylePennell You have to const csv = require('csv-parse') which imports the whole module and then use the parse method of that with csv.parse(...

Ajeet Verma · Accepted Answer · 2025-05-17 06:49:37Z

1

you can also use csv-for-you npm package

const csv=require("csv-for-you");
function readFile async(filePath){
  const lines = await csv.parse(filePath);
}
readFile("/path/to/your/file.csv");

edited May 17 at 6:49

Ajeet Verma

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answered May 16 at 15:32

Michael Scharff

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Comments

Ahti Ahde · Accepted Answer · 2017-10-20 17:43:06Z

0

From How to read data From *.CSV file using javascript?, use the jQuery-CSV library.

Note: The library is designed to handle any CSV data that is RFC 4180 compliant, including all of the nasty edge cases that most 'simple' solutions overlook.

var fs = require('fs');
var $ = jQuery = require('jquery');
$.csv = require('jquery-csv');

var sample = './path/to/data/sample.csv';
fs.readFile(sample, 'UTF-8', function(err, csv) {
  $.csv.toArrays(csv, {}, function(err, data) {
    for(var i=0, len=data.length; i<len; i++) {
      console.log(data[i]); //Will print every csv line as a newline
    }
  });
});

code snippet from jquery-csv's examples here.

edited Oct 20, 2017 at 17:43

Ahti Ahde

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answered Jul 19, 2017 at 6:43

zelusp

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