PEP 661 has been officially accepted after 5 years, introducing standardized sentinel values for Python 3.15. The proposal addresses the common need for unique placeholder values distinct from None in function defaults, return values, and missing data scenarios. This provides a canonical implementation for a pattern previously implemented ad-hoc by developers.
Background
Sentinel values are unique placeholder objects used in programming to represent special states like missing data or unprovided arguments. Python developers have historically created these using object() or other ad-hoc methods without standardization.
- Source
- Lobsters
- Published
- May 3, 2026 at 01:26 AM
- Score
- 6.0 / 10