rusty

Rust-based Python module experiments.

Installing Rust

Follow the instructions here to download and install the official compiler for the Rust programming language, and its package manager, Cargo.

$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Exit the shell, restart terminal. You should be able to check the version of the rustc compiler as follows:

$ rusty % rustc --version
rustc 1.82.0 (f6e511eec 2024-10-15)

Installing Maturin

$ mkdir rusty
$ cd rusty
$ mkvirtualenv rusty
(rusty) $ pip install maturin

We’re going to use PyO3 to bind Python and Rust together. We will do this using maturin to simplify the process. Maturin allows you to:

build and publish crates with pyo3, cffi and uniffi bindings as well as Rust binaries as Python packages with minimal configuration.

(rusty) $ maturin init
You should see the following structure created by default:
(rusty) $ ls -R 
Cargo.toml	pyproject.toml	src
./src:
lib.rs

Here is what it creates by default:

use pyo3::prelude::*;

/// Formats the sum of two numbers as string.
#[pyfunction]
fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
    Ok((a + b).to_string())
}

/// A Python module implemented in Rust.
#[pymodule]
fn rusty2(m: &Bound<'_, PyModule>) -> PyResult<()> {
    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
    Ok(())
}

Now we can try to modify this default module implementation to incorporate the add_one function presented in the Rust London meetup on 22.10.24 by David Seddon:

as the following wrapped function added to the module:

/// Adds 1 to the input integer.
#[pyfunction]
fn add_one(x: i32) -> PyResult<i32> {
    Ok(x + 1)
}
...
    m.add_function(wrap_pyfunction!(add_one, m)?)?;

The code in lib.rs includes add_one and also a factorial implementation. Now we can build this into a python module using maturin as follows:

(rusty) $ maturin develop                    
🔗 Found pyo3 bindings
🐍 Found CPython 3.11 at /Users/malm/.virtualenvs/rusty/bin/python
📡 Using build options features from pyproject.toml
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
📦 Built wheel for CPython 3.11 to /var/folders/bb/9r_ys971201g8f0zpkp20t8c0000gn/T/.tmpRr6jcT/rusty-0.1.0-cp311-cp311-macosx_11_0_arm64.whl
✏️  Setting installed package as editable
🛠 Installed rusty-0.1.0

And run the accompanying test_rusty.py test code which compares timings between Python and Python implementations of factorial:

(rusty) $ python test_rusty.py               
time for rust code: 0.92 sec
time for python code: 2.35 sec
Rust implementation is 2.56 times faster than Python one