code: def already_downloaded(track, title, filename):
      
      global arguments
      already_downloaded = False
  
      if os.path.isfile(filename):
          already_downloaded = True
      if arguments['--flac'] and can_convert(filename) \
                             and os.path.isfile(filename[:-4] + ".flac"):
          already_downloaded = True
      if arguments['--download-archive'] and in_download_archive(track):
          already_downloaded = True
  
      if arguments['--flac'] and can_convert(filename) and os.path.isfile(filename):
          already_downloaded = False
  
      if already_downloaded:
          if arguments['-c'] or arguments['--remove']:
              logger.info('Track "{0}" already downloaded.'.format(title))
              return True
          else:
              logger.error('Track "{0}" already exists!'.format(title))
              logger.error('Exiting... (run again with -c to continue)')
              sys.exit(0)
      return False
docs: Returns True if the file has already been downloaded