Overview

msgspec 0.18.5, released on December 12, 2023, adds cache_hash and custom dictionary keys.

Main Features

cache_hash and custom keys

cache_hash=True pre-computes the hash of Structs for efficient use in sets and dictionaries. Dictionary keys can be custom types like enums.

python 
import msgspec

class Point(msgspec.Struct, frozen=True, cache_hash=True):
    x: int
    y: int

# Pre-computed hash: fast in sets
points = {Point(0, 0), Point(1, 1), Point(0, 0)}
print(len(points))  # 2

Sources