def _cmp_by_aspath(path1, path2):
 as_path1 = path1.get_pattr(BGP_ATTR_TYPE_AS_PATH)
 as_path2 = path2.get_pattr(BGP_ATTR_TYPE_AS_PATH)
 assert (as_path1 and as_path2)
 l1 = as_path1.get_as_path_len()
 l2 = as_path2.get_as_path_len()
 assert ((l1 is not None) and (l2 is not None))
 if (l1 > l2):
  return path2
 elif (l2 > l1):
  return path1
 else:
  return None

def _cmp_by_aspath ( path1 , path2 ) : as_path1 = path1 . get_pattr ( BGP_ATTR_TYPE_AS_PATH ) as_path2 = path2 . get_pattr ( BGP_ATTR_TYPE_AS_PATH ) assert ( as_path1 and as_path2 ) l1 = as_path1 . get_as_path_len ( ) l2 = as_path2 . get_as_path_len ( ) assert ( ( l1 is not None ) and ( l2 is not None ) ) if ( l1 > l2 ) : return path2 elif ( l2 > l1 ) : return path1 else : return None
calculated the best-paths by comparing as-path lengths .