NodeJS script to lookup carrier information in parallel using the paid service twilio. (https://www.twilio.com/docs/api/lookups) The data is read from a CSV-file, parsed, processed and written to the output csv-file.

carrierLookup.js

// Install dependencies
// npm i -s node-fetch csv-writer csvtojson

const fetch = require('node-fetch');
const csvToJson = require('csvtojson');
const createCsvWriter = require('csv-writer').createObjectCsvWriter;

function lookup(phonenumber) {
	const sid = '__YOUR_TWILIO_SID__';
	const token = '__YOUR_TWILIO_AUTH_TOKEN__';
	const url = `https://${sid}:${token}@lookups.twilio.com/v1/PhoneNumbers/${phonenumber}?Type=carrier&countryCode=US`;

	return fetch(url).then(res => res.json()).then(data => {
		const {carrier = {}} = data || {};
		const {name = ''} = carrier;

		return name;
	}).catch(function(e) {
		console.log(e);
	});
}

async function append(data, file) {
	const csvWriter = createCsvWriter({
		path: file,
		header: [
			{id: 'GID', title: 'GID'},
			{id: 'Mobile', title: 'Mobile'},
			{id: 'Phone', title: 'Phone'},
			{id: 'Lead Status', title: 'Lead Status'},
			{id: 'Lead Creation Datetime', title: 'Lead Creation Datetime'},
			{id: 'CarrierMobile', title: 'Carrier Mobile'},
			{id: 'CarrierPhone', title: 'Carrier Phone'},
		],
		append: true,
	});

	return csvWriter.writeRecords(data).then(() => console.log('Append to file ...ok'));
}

function createSet(arr, type) {
	return arr.filter(item => item[type]).map(item => item[type]);
}

async function lookupAndAppendCarrierData(leadData, type) {
	const set = createSet(leadData, type);
	const nums = set.map(item => lookup(item));
	const procNums = await Promise.all(nums);
	let j = 0;

	for (let i = 0; i < leadData.length; i++) {
		const lead = leadData[i];

		if (lead[type]) {
			lead['Carrier'+type] = procNums[j];
			j++
		}
	}

	return leadData;
}

async function processChunk(leadData, fileOutput) {
	leadData = await lookupAndAppendCarrierData(leadData, 'Phone');
	leadData = await lookupAndAppendCarrierData(leadData, 'Mobile');
	await append(leadData, fileOutput);
}

async function run() {
	const file = 'leads_2019';
	const fileInput = `${file}.csv`;
	const fileOutput = `${file}_done.csv`;

	const leadData = await csvToJson().fromFile(fileInput);
	const chunkSize = 200;
	const startOffset = 0;
	const stopAfterNumberOfLines = startOffset * chunkSize + 20000;
	const numChunks = Math.ceil(leadData.length / chunkSize);

	for (var i = startOffset; i < numChunks; i++) {
		const start = i * chunkSize;
		const end = (i + 1) * chunkSize;
		const chunk = leadData.slice(start, end);

		console.log(`Processing chunk ${start} - ${end} (${i})`);

		await processChunk(chunk, fileOutput);

		console.log(`> Done (${i})`);

		if (end >= stopAfterNumberOfLines) {
			console.log(`>> Stopped at ${stopAfterNumberOfLines} <<`);
			break;
		}
	}
}

run();