code: def log(args, kwargs):
      
      logfile = os.path.join(args.logdir, 'log.tsv')
  
      if 'log_created' not in globals():
          if os.path.exists(logfile):
              logging.error('Logfile %s already exists.', logfile)
              sys.exit(1)
  
          global log_created
  
          log_created = sorted(kwargs.keys())
          header = '\t'.join((str(k) for k in log_created)) + '\n'
          with open(logfile, 'w') as f:
              f.write(header)
  
      # Log variables shouldn't change during training
      assert log_created == sorted(kwargs.keys())
  
      with open(logfile, 'a') as f:
          f.write('\t'.join((str(kwargs[k]) for k in log_created)) + '\n')
docs: Log to a file.