sexp 2.0.0

A minimal-allocation S-expression library for Python, backed by Rust.

sexp

A fast S-expression library for Python.

Installation

pip install sexp

Requires Python 3.10+. Wheels are provided for Linux (x86_64 + aarch64), macOS (x86_64 + arm64), and Windows (AMD64).

Quick start

from sexp import parse

tree = parse("(define (square x) (* x x))")

tree[0].value         # 'define'
tree[1][0].value      # 'square'
tree.head.value       # 'define'

for node in tree:
    print(node)

src = "(a (b (c d)) e)"
assert repr(parse(src)) == src

Further reading

Path	Contents
CHANGELOG.md	Release history
docs/api.md	Full API reference
docs/guide.md	User guide: navigation, mutation, patterns

Development

Prerequisites

• Python 3.10+
• Rust stable toolchain (for building from source)

Setup

python -m venv .venv && source .venv/bin/activate  # Windows: .venv\Scripts\activate
pip install maturin
make dev
pip install -e '.[dev]'

Common tasks

make test        Run Python tests
make test-rs     Run Rust unit tests
make test-all    Run all tests
make lint        Lint (ruff + clippy)
make format      Auto-format (ruff + rustfmt)
make typecheck   mypy
make bench       Run benchmarks
make help        Show all available targets

License

MIT