rust-numpy

Rust bindings for the NumPy C-API

API documentation

Requirements

current nightly rust (see PyO3/pyo3#5 for nightly features, and https://github.com/PyO3/pyo3/blob/master/build.rs for minimum required version)
some rust libraries
- ndarray for rust-side matrix library
- pyo3 for cpython binding
- and more (see Cargo.toml)
numpy installed in your python environments (e.g., via pip install numpy)

Note Starting from 0.3, rust-numpy migrated from rust-cpython to pyo3. If you want to use rust-cpython, use version 0.2.1 from crates.io.

Supported Python version

Currently 3.5, 3.6, 3.7 are supported.

Python2 Support

Version 0.5.0 is the last version that supports Python2.

If you want to compile this library with Python2, please use 0.5.0 from crates.io.

In addition, you have to add a feature flag in Cargo.toml like

[dependencies.numpy]
version = "0.5.0"
features = ["python2"]

You can also automatically specify python version in setup.py, using setuptools-rust.

Example

Execute a Python program from Rust and get results

[package]
name = "numpy-test"

[dependencies]
pyo3 = "0.6.0"
numpy = "0.5.0"

extern crate numpy;
extern crate pyo3;
use numpy::{PyArray1, get_array_module};
use pyo3::prelude::{ObjectProtocol, PyResult, Python};
use pyo3::types::PyDict;

fn main() -> Result<(), ()> {
    let gil = Python::acquire_gil();
    main_(gil.python()).map_err(|e| {
        eprintln!("error! :{:?}", e);
        // we can't display python error type via ::std::fmt::Display
        // so print error here manually
        e.print_and_set_sys_last_vars(gil.python());
    })
}

fn main_<'py>(py: Python<'py>) -> PyResult<()> {
    let np = py.import("numpy")?;
    let dict = PyDict::new(py);
    dict.set_item("np", np)?;
    let pyarray: &PyArray1<i32> = py
        .eval("np.absolute(np.array([-1, -2, -3], dtype='int32'))", Some(&dict), None)?
        .extract()?;
    let slice = pyarray.as_slice();
    assert_eq!(slice, &[1, 2, 3]);
    Ok(())
}

Write a Python module in Rust

Please see the example directory for a complete example

[lib]
name = "rust_ext"
crate-type = ["cdylib"]

[dependencies]
numpy = "0.5.0"
ndarray = "0.12"

[dependencies.pyo3]
version = "0.6.0"
features = ["extension-module"]

extern crate ndarray;
extern crate numpy;
extern crate pyo3;

use ndarray::{ArrayD, ArrayViewD, ArrayViewMutD};
use numpy::{IntoPyArray, PyArrayDyn};
use pyo3::prelude::{pymodule, Py, PyModule, PyResult, Python};

#[pymodule]
fn rust_ext(_py: Python, m: &PyModule) -> PyResult<()> {
    // immutable example
    fn axpy(a: f64, x: ArrayViewD<f64>, y: ArrayViewD<f64>) -> ArrayD<f64> {
        a * &x + &y
    }

    // mutable example (no return)
    fn mult(a: f64, mut x: ArrayViewMutD<f64>) {
        x *= a;
    }

    // wrapper of `axpy`
    #[pyfn(m, "axpy")]
    fn axpy_py(
        py: Python,
        a: f64,
        x: &PyArrayDyn<f64>,
        y: &PyArrayDyn<f64>,
    ) -> Py<PyArrayDyn<f64>> {
        let x = x.as_array();
        let y = y.as_array();
        axpy(a, x, y).into_pyarray(py).to_owned()
    }

    // wrapper of `mult`
    #[pyfn(m, "mult")]
    fn mult_py(_py: Python, a: f64, x: &PyArrayDyn<f64>) -> PyResult<()> {
        let x = x.as_array_mut();
        mult(a, x);
        Ok(())
    }

    Ok(())
}

Contribution

We need your feedback.

Don't hesitate to open issues!

Version

v0.5.0
- Update PyO3 to 0.6
v0.4.0
- Duplicate PyArrayModule and import Numpy API automatically
- Fix memory leak of IntoPyArray and add ToPyArray crate
- PyArray has dimension as type parameter. Now it looks like PyArray<T, D>
- Use ndarray::IntoDimension to specify dimension
- Python2 support
v0.3.1, v0.3.2
- Just update dependencies
v0.3.0
- Breaking Change: Migrated to pyo3 from rust-cpython
- Some api addition
- Static type checking with PhantomData
v0.2.1
- NEW: trait IntoPyErr, IntoPyResult for error translation
v0.2.0
- NEW: traits IntoPyArray, ToPyArray
- MOD: Interface of PyArray creation functions are changed
v0.1.1
- Update documents
v0.1.0
- First Release
- Expose unsafe interface of Array and UFunc API

bmatthieu3/rust-numpy