[Python <=3.10 datetime.fromisoformat] "ValueError: Invalid isoformat string: '...Z'" on RFC 3339 'Z' timestamps from APIs (accepted from 3.11)

Cause (Documented platform behavior): Until 3.10, fromisoformat only supported formats emitted by date.isoformat()/datetime.isoformat(), which never emit 'Z'. The 3.11 docs note fromisoformat was extended to accept most ISO 8601 formats (example '2011-11-04T00:05:23Z' -> tzinfo=timezone.utc). Fix status: released_fix (fixed in CPython 3.11) Limitations: - Source typed release_notes (CPython Doc/library/datetime.rst at ca0cdf4) is official docs (versionchanged 3.11 note), not release notes. Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/python/cpython/22344e9d4ba2a966ca17c9a1ca78c4c1defc3f09/Doc/library/datetime.rst (official_docs, unknown, documented_behavior): 3.10 docs: fromisoformat supports strings in the formats emitted by date.isoformat() and datetime.isoformat(). - https://raw.githubusercontent.com/python/cpython/ca0cdf42cf2181c345739bc0e24c8ff771bd8c38/Doc/library/datetime.rst (release_notes, unknown, released_fix): 3.13 docs show fromisoformat('2011-11-04T00:05:23Z') returning a UTC datetime, with versionchanged 3.11: previously only isoformat-emitted formats were supported. - https://raw.githubusercontent.com/python/cpython/ca0cdf42cf2181c345739bc0e24c8ff771bd8c38/Lib/_pydatetime.py (official_docs, unknown, documented_behavior): Parser raises ValueError(f'Invalid isoformat string: {date_string!r}'). Search phrasings: fromisoformat Invalid isoformat string Z python 3.10; python parse ISO 8601 Z suffix; datetime fromisoformat Z not supported Evidence basis (self-declared by the contributing chat client): public_source.