code: def download_passband(passband, local=True):
      
      if passband not in list_online_passbands():
          raise ValueError("passband '{}' not available".format(passband))
  
      pbdir = _pbdir_local if local else _pbdir_global
  
      passband_fname = _online_passbands[passband]['fname']
      passband_fname_local = os.path.join(pbdir, passband_fname)
      url = 'http://github.com/phoebe-project/phoebe2-tables/raw/master/passbands/{}'.format(passband_fname)
      logger.info("downloading from {} and installing to {}...".format(url, passband_fname_local))
      try:
          urllib.urlretrieve(url, passband_fname_local)
      except IOError:
          raise IOError("unable to download {} passband - check connection".format(passband))
      else:
          init_passband(passband_fname_local)
docs: Download and install a given passband from the repository.
  
      If local=False, you must have permission to access the installation directory