PyYAML

PyYAML is a YAML 1.1 parser and emitter for Python, providing safe and unsafe loaders, a complete Unicode-aware parser, pickle-compatible serialisation, and a capable extension API for custom tags and representers. Current version is 6.0.3 (released September 2025), which adds Python 3.14 and experimental free-threading support. The 6.x line follows an irregular maintenance cadence with patch releases typically spaced 1–2 years apart; a 7.0 dev branch exists but has no published release date.