| 1 | """Shared helpers for extracting normalized fields from raw Douyin aweme payloads. |
| 2 | |
| 3 | These helpers centralize the payload-shape dereferencing so that callers across |
| 4 | downloaders (``downloader_base``, ``music_downloader``, future strategies, …) |
| 5 | all agree on how to pull fields like ``author.sec_uid`` out of the various |
| 6 | aweme dict shapes returned by the upstream API. |
| 7 | """ |
| 8 | |
| 9 | from __future__ import annotations |
| 10 | |
| 11 | from typing import Any, Mapping, Optional |
| 12 | |
| 13 | |
| 14 | def extract_author_sec_uid(aweme: Optional[Mapping[str, Any]]) -> Optional[str]: |
| 15 | """Return ``aweme["author"]["sec_uid"]`` or ``None`` if unavailable. |
| 16 | |
| 17 | Defensive against every shape variation observed so far: |
| 18 | * ``aweme`` itself being ``None`` or not a mapping |
| 19 | * ``aweme["author"]`` being missing, ``None``, or not a mapping |
| 20 | * ``sec_uid`` being missing, ``None``, or an empty / whitespace string |
| 21 | (all collapse to ``None`` so downstream consumers can treat NULL and |
| 22 | empty-string identically). |
| 23 | """ |
| 24 | |
| 25 | if not isinstance(aweme, Mapping): |
| 26 | return None |
| 27 | author = aweme.get("author") |
| 28 | if not isinstance(author, Mapping): |
| 29 | return None |
| 30 | sec_uid = author.get("sec_uid") |
| 31 | if not isinstance(sec_uid, str): |
| 32 | return None |
| 33 | sec_uid = sec_uid.strip() |
| 34 | return sec_uid or None |
| 35 |