Immutable Collections

The `immutables` library for Python provides a high-performance immutable mapping type, `immutables.Map`, built on a Hash Array Mapped Trie (HAMT) data structure. It offers efficient (O(log N)) operations for setting and getting values, making it suitable for functional programming paradigms and scenarios where data integrity and thread safety are paramount. The current version is 0.21. It follows a release cadence driven by bug fixes and performance improvements.