| # Copyright 2018 The ChromiumOS Authors |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Chromite extensions on top of the collections module.""" |
| |
| from typing import Dict, Iterable, List, NamedTuple, Optional |
| |
| |
| def GroupNamedtuplesByKey( |
| input_iter: Iterable[NamedTuple], key: str |
| ) -> Dict[Optional[str], List[NamedTuple]]: |
| """Split an iterable of namedtuples, based on value of a key. |
| |
| Args: |
| input_iter: An iterable of namedtuples. |
| key: A string specifying the key name to split by. |
| |
| Returns: |
| A dictionary, mapping from each unique value for |key| that |
| was encountered in |input_iter| to a list of entries that had |
| that value. |
| """ |
| split_dict: Dict[Optional[str], List[NamedTuple]] = {} |
| for entry in input_iter: |
| split_dict.setdefault(getattr(entry, key, None), []).append(entry) |
| return split_dict |
