cargo-single-pyo3

Utility to build Python modules from a single Rust files via pyo3. Inspired by cargo-single.

Installation

cargo install cargo-single-pyo3

Example

First, create a single Rust file with a pyo3 module. Add any dependencies as double-slash comments at the top of the file. For example, if you create foo.rs with the contents:

```rust // rand = "*"

use pyo3::prelude::*; use pyo3::wrap_pyfunction;

[pyfunction]

fn sumasstring(a: usize, b: usize) -> PyResult { // using rand to demonstrate library support let c = rand::threadrng().genrange(0 ..= 1); Ok((a + b + c).to_string()) }

[pymodule]

fn foo(py: Python, m: &PyModule) -> PyResult<()> { m.addfunction(wrappyfunction!(sumasstring, m)?)?; Ok(()) } ```

Then run:

cargo single-pyo3 foo.rs

This should generate a file foo.so, which you can then import:

``` $ python3

import foo foo.sumasstring(1, 2) '3' foo.sumasstring(2, 2) '5' ```

Usage notes

Module name: the name of the file is the name of the module, e.g. foo.rs generates foo.so. The name of the #[pymodule] function must be the same.

Build process: the tool creates a Cargo project in your temporary directory that is associated with the module name, e.g. /tmp/foo. This could cause any usual problems of conflicts between users or projects on the same machine, so be careful (or submit a PR if you have a different preference).

Pyo3 version: the Cargo dependency on pyo3 is automatically generated. If you need to change the version, use the --pyo3 flag, e.g. --pyo3 0.13. You can also use --pyo3 github to use the latest on main branch. As of 5/7/21, the github option was necessary to build on OS X.