load-csv.js

const fs = require("fs");
const _ = require("lodash");
const shuffleSeed = require("shuffle-seed");

function extractColumns(data, columnNames) {
  const headers = _.first(data);
  const indexes = _.map(columnNames, column => headers.indexOf(column));
  const extracted = _.map(data, row => _.pullAt(row, indexes));
  return extracted;
}

function loadCSV(
  filename,
  {
    converters = {},
    dataColumns = [],
    labelColumns = [],
    shuffle = true,
    splitTest = false
  }
) {
  let data = fs.readFileSync(filename, { encoding: "utf-8" });
  data = data.split("\n").map(row => row.split(","));
  data = data.map(row => _.dropRightWhile(row, val => val === ""));
  const headers = _.first(data);
  data = data.map((row, index) => {
    if (index === 0) {
      return row;
    }
    return row.map((element, index) => {
      if (converters[headers[index]]) {
        const converted = converters[headers[index]](element);
        return _.isNaN(converted) ? element : converted;
      }
      const result = parseFloat(element);
      return _.isNaN(result) ? element : result;
    });
  });
  let labels = extractColumns(data, labelColumns);
  data = extractColumns(data, dataColumns);
  data.shift();
  labels.shift();
  if (shuffle) {
    data = shuffleSeed.shuffle(data, "phrase");
    labels = shuffleSeed.shuffle(labels, "phrase");
  }
  if (splitTest) {
    const trainSize = _.isNumber(splitTest)
      ? splitTest
      : Math.floor(data.length / 2);
    return {
      features: data.slice(trainSize),
      labels: labels.slice(trainSize),
      testFeatures: data.slice(0, trainSize),
      testLabels: data.slice(0, trainSize)
    };
  } else {
    return { features: data, labels: labels };
  }
}

const { features, labels, testFeatures, testLabels } = loadCSV("data.csv", {
  dataColumns: ["height", "value"],
  labelColumns: ["passed"],
  shuffle: true,
  splitTest: 1,
  converters: {
    passed: val => (val === "TRUE" ? true : false)
  }
});
console.log(
  "features",
  features,
  "labels",
  labels,
  "testFeatures",
  testFeatures,
  "testLabels",
  testLabels
);