README.md

Rust Async Extension Example

This example shows how to keep rsloop as the Python event loop while adding your own async Rust functions in a separate PyO3 extension module.

The extension uses rsloop::rust_async::future_into_py(...) to turn a Rust future into a Python awaitable attached to the current running loop.

Files

• src/lib.rs: example Rust extension module
• demo.py: Python code that awaits the Rust functions while running on rsloop
• Cargo.toml / pyproject.toml: local build config for maturin

Run

From the folder, the simplest end-to-end run is:

uv run --with maturin maturin develop --release
uv run --with rsloop python demo.py

If you only want to check the Rust builds, use:

cargo check
cargo check --manifest-path examples/rust/Cargo.toml

In your own extension crate, the important pattern is:

#[pyfunction]
fn my_async_fn(py: Python<'_>) -> PyResult<Bound<'_, PyAny>> {
    rsloop::rust_async::future_into_py(py, async move {
        // your async Rust work here
        Ok("done")
    })
}