code: import os
  import pandas as pd
  from demo import utils
  
  URL = r'https://ti.arc.nasa.gov/c/6/'
  PWD = os.path.dirname(__file__)
  
  
  def _download_data():
      output = os.path.join(PWD, 'download')
      utils.download(URL, output)
  
  
  def _data():
      path = os.path.join(PWD, 'download', 'train_FD004.txt')
      if not os.path.exists(path): _download_data()
      cols = ['engine_no', 'time_in_cycles']
      cols += ['operational_setting_{}'.format(i + 1) for i in range(3)]
      cols += ['sensor_measurement_{}'.format(i + 1) for i in range(26)]
      df = pd.read_csv(path, sep=' ', header=None, names=cols)
      df = df.drop(cols[-5:], axis=1).rename_axis('id')
      df['time'] = pd.date_range('1/1/2000', periods=df.shape[0], freq='600s')
      return df
  
  
  def _read(file):
      path = os.path.join(PWD, file)
      df = pd.read_csv(path, parse_dates=['time'], index_col='id')
      return df
  
  
  def load_sample():
      return _read('sample.csv')
  
apis: pandas.read_csv pandas.date_range