rust-cpython

Rust bindings for the python interpreter.

Documentation
Cargo package: cpython

Supported Python versions: * Python 2.7 * Python 3.3 to 3.9

Requires Rust 1.41.1 or later.

Usage

To use cpython, add this to your Cargo.toml:

toml [dependencies] cpython = "0.6"

Example program displaying the value of `sys.version`:

```rust use cpython::{Python, PyDict, PyResult};

fn main() { let gil = Python::acquire_gil(); hello(gil.python()).unwrap(); }

fn hello(py: Python) -> PyResult<()> { let sys = py.import("sys")?; let version: String = sys.get(py, "version")?.extract(py)?;

let locals = PyDict::new(py);
locals.set_item(py, "os", py.import("os")?)?;
let user: String = py.eval("os.getenv('USER') or os.getenv('USERNAME')", None, Some(&locals))?.extract(py)?;

println!("Hello {}, I'm Python {}", user, version);
Ok(())

} ```

Example library with python bindings:

The following two files will build with cargo build, and will generate a python-compatible library. On Mac OS, you will need to rename the output from *.dylib to *.so. On Windows, you will need to rename the output from *.dll to *.pyd.

Note:

At build time python3-sys/build.rs will look for interpreters in: * PYTHON_SYS_EXECUTABLE * python * python3

picking the first one that works and is compatible with the configured expected version (by default, any Python 3.X interpreter will do). If a specific interpreter is desired, the PYTHON_SYS_EXECUTABLE environment variable should point to it.

Cargo.toml: ```toml [lib] name = "rust2py" crate-type = ["cdylib"]

[dependencies.cpython] version = "0.6" features = ["extension-module"] ```

src/lib.rs ```rust use cpython::{PyResult, Python, pymoduleinitializer, py_fn};

// add bindings to the generated python module // N.B: names: "rust2py" must be the name of the .so or .pyd file pymoduleinitializer!(rust2py, |py, m| { m.add(py, "doc", "This module is implemented in Rust.")?; m.add(py, "sumasstring", pyfn!(py, sumasstringpy(a: i64, b:i64)))?; Ok(()) });

// logic implemented as a normal rust function fn sumasstring(a:i64, b:i64) -> String { format!("{}", a + b).to_string() }

// rust-cpython aware function. All of our python interface could be // declared in a separate module. // Note that the pyfn!() macro automatically converts the arguments from // Python objects to Rust values; and the Rust return value back into a Python object. fn sumasstringpy(: Python, a:i64, b:i64) -> PyResult { let out = sumas_string(a, b); Ok(out) } ```

On windows and linux, you can build normally with cargo build --release. On Mac Os, you need to set additional linker arguments. The simplest solution is to create a .cargo/config with the following content:

[target.x86_64-apple-darwin] rustflags = [ "-C", "link-arg=-undefined", "-C", "link-arg=dynamic_lookup", ]

For setup.py integration, see https://github.com/PyO3/setuptools-rust

Development

To build the crate, run: make build

To test the crate, run: make test