Function $openCsvInputStream

src/danfojs-base/io/node/io.csv.ts:338–425

(filePath: string, options: CsvInputOptionsNode)

 * ```
 */
const $openCsvInputStream = (filePath: string, options: CsvInputOptionsNode) => {
  const { header } = { header: true, ...options }
  let isFirstChunk = true
  let ndFrameColumnNames: any = []

  const csvInputStream = new stream.Readable({ objectMode: true });
  csvInputStream._read = () => { };

  if (filePath.startsWith("http") || filePath.startsWith("https")) {
    const dataStream = request.get(filePath);

    // reject any non-2xx status codes
    dataStream.on('response', (response: any) => {
      if (response.statusCode < 200 || response.statusCode >= 300) {
        throw new Error(`HTTP ${response.statusCode}: ${response.statusMessage}`);
      }
    });

    const parseStream: any = Papa.parse(Papa.NODE_STREAM_INPUT, { header, dynamicTyping: true, ...options });
    dataStream.pipe(parseStream);
    let count = 0

    parseStream.on("data", (chunk: any) => {
      if (isFirstChunk) {
        if (header === true) {
          ndFrameColumnNames = Object.keys(chunk)
        } else {
          ndFrameColumnNames = chunk
        }
        isFirstChunk = false
        return
      }

      const df = new DataFrame([Object.values(chunk)], {
        columns: ndFrameColumnNames,
        index: [count++]
      })
      csvInputStream.push(df);
    });

    parseStream.on("finish", () => {
      csvInputStream.push(null);
      return (null);
    });

    return csvInputStream;
  } else {
    const fileStream = fs.createReadStream(filePath)

    fs.access(filePath, fs.constants.F_OK, (err) => {
      if (err) {
        throw new Error("ENOENT: no such file or directory");
      }

      let count = 0
      Papa.parse(fileStream, {
        ...{ header, dynamicTyping: true, ...options },
        step: results => {