Pydantic ships Monty v1.2.0: match statements plus five new stdlib modules for embedded Python

samuelcolvin · x · 2026-10-19

Pydantic released Monty v1.2.0, a major update to its embedded Python interpreter:

match statements (structural pattern matching) now supported
New stdlib modules: hashlib, os.path, csv, tomllib, bisect; plus json.load/json.dump
Dataclasses support field(), defaultfactory and postinit
New import host call; many more dunder methods work on user-defined class instances
open() honours newline, file objects are iterable, Path.scan added
List slice assignment, set/frozenset ordering comparisons, capture groups in re.split()

Monty targets embedded use cases and moves significantly closer to CPython compatibility.

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