def _partition_index_names(provisioned_index_names, index_names):
 existing_index_names = set()
 new_index_names = set()
 for name in index_names:
  if (name in provisioned_index_names):
   existing_index_names.add(name)
  else:
   new_index_names.add(name)
 index_names_to_be_deleted = (provisioned_index_names - existing_index_names)
 return (existing_index_names, new_index_names, index_names_to_be_deleted)

def _partition_index_names ( provisioned_index_names , index_names ) : existing_index_names = set ( ) new_index_names = set ( ) for name in index_names : if ( name in provisioned_index_names ) : existing_index_names . add ( name ) else : new_index_names . add ( name ) index_names_to_be_deleted = ( provisioned_index_names - existing_index_names ) return ( existing_index_names , new_index_names , index_names_to_be_deleted )
returns 3 disjoint sets of indexes: existing .