Python
09 Sep 2026
12 min read
Model UUID Sentinels with uuid.NIL and uuid.MAX
UUIDs are often treated as ordinary identifiers: generate one, store it, compare it, and pass it between services. But some systems also need boundary or sentinel UUID values. A protocol may reserve an all-zero identifier for “no object.” A range query may need the lowest or highest possible UUID. Test fixtures may need deterministic endpoints without inventing magic strings. Python 3.14 makes those cases explicit with two constants from RFC 9562: