Parsing a CSV file using NodeJS

Question

With nodejs I want to parse a .csv file of 10000 records and do some operation on each row. I tried using http://www.adaltas.com/projects/node-csv. I couldnt get this to pau

Answer 1

Try the line by line npm plugin.

npm install line-by-line --save

Answer 2

Seems like you need to use some stream based solution, there existed already such libraries so before reinventing yourself, try this library, which also includes validation support. https://www.npmjs.org/package/fast-csv

Answer 3

this is my solution to get csv file from external url

const parse = require( 'csv-parse/lib/sync' );
const axios = require( 'axios' );
const readCSV = ( module.exports.readCSV = async ( path ) => {
try {
   const res = await axios( { url: path, method: 'GET', responseType: 'blob' } );
   let records = parse( res.data, {
      columns: true,
      skip_empty_lines: true
    } );

    return records;
 } catch ( e ) {
   console.log( 'err' );
 }

} );
readCSV('https://urltofilecsv');

Answer 4

In order to pause the streaming in fast-csv you can do the following:

let csvstream = csv.fromPath(filePath, { headers: true })
    .on("data", function (row) {
        csvstream.pause();
        // do some heavy work
        // when done resume the stream
        csvstream.resume();
    })
    .on("end", function () {
        console.log("We are done!")
    })
    .on("error", function (error) {
        console.log(error)
    });