Python's frozendict Is Finally Happening — And It's More Important Than You Think

Python 3.15 ships a built-in frozendict — hashable, O(1) lookups, order-preserving, thread-safe by design. Here's the full technical picture: the 14-year history, how hashing works, what it unlocks for lru_cache and free-threaded Python, and every sharp edge you need to know before you use it.

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