GoKawiilRust JSON parser exposed to Python via PyO3 mirrors Pydantic-core's approach
A tutorial demonstrates how to write a JSON parser in Rust and expose it to Python using PyO3, the same toolchain that powers pydantic-core, the Rust extension underlying Pydantic v2's validation speed. The guide walks through the four steps of bridging Rust and Python—writing a Rust module, annotating it with PyO3 macros, compiling with maturin, and importing it as a normal package—while flagging that converting Rust results back into Python objects can be more expensive than the parsing itself. It references a cohort where students built hand-rolled JSON parsers in Rust that outperformed CPython's built-in json module, in one case by up to 3.5x.