Rust bindings for the Python interpreter. This includes running and interacting with python code from a rust binaries as well as writing native python modules.
A comparison with rust-cpython can be found in the guide.
Pyo3 supports python 2.7 as well as python 3.5 and up. The minimum required rust version is 1.27.0-nightly 2018-05-01.
To use pyo3, add this to your Cargo.toml:
toml
[dependencies]
pyo3 = "0.3"
Example program displaying the value of sys.version:
```rust
extern crate pyo3;
use pyo3::prelude::*;
fn main() -> PyResult<()> { let gil = Python::acquire_gil(); let py = gil.python(); let sys = py.import("sys")?; let version: String = sys.get("version")?.extract()?;
let locals = PyDict::new(py);
locals.set_item("os", py.import("os")?)?;
let user: String = py.eval("os.getenv('USER') or os.getenv('USERNAME')", None, Some(&locals))?.extract()?;
println!("Hello {}, I'm Python {}", user, version);
Ok(())
} ```
Pyo3 can be used to generate a python-compatible library.
Cargo.toml:
```toml [package] name = "rust2py" version = "0.1.0"
[lib] name = "rust2py" crate-type = ["cdylib"]
[dependencies.pyo3] version = "0.3" features = ["extension-module"] ```
src/lib.rs
```rust
extern crate pyo3; use pyo3::prelude::*;
// Add bindings to the generated python module
// N.B: names: "librust2py" must be the name of the .so or .pyd file
/// This module is implemented in Rust.
fn rust2py(py: Python, m: &PyModule) -> PyResult<()> {
#[pyfn(m, "sum_as_string")]
// ``#[pyfn()]` converts the arguments from Python objects to Rust values
// and the Rust return value back into a Python object.
fn sum_as_string_py(a:i64, b:i64) -> PyResult<String> {
let out = sum_as_string(a, b);
Ok(out)
}
Ok(())
}
// The logic can be implemented as a normal rust function fn sumasstring(a:i64, b:i64) -> String { format!("{}", a + b).to_string() } ```
On windows and linux, you can build normally with cargo build --release. On Mac Os, you need to set additional linker arguments. One option is to compile with cargo rustc --release -- -C link-arg=-undefined -C link-arg=dynamic_lookup, the other is to create a .cargo/config with the following content:
toml
[target.x86_64-apple-darwin]
rustflags = [
"-C", "link-arg=-undefined",
"-C", "link-arg=dynamic_lookup",
]
Also on macOS, you will need to rename the output from *.dylib to *.so. On Windows, you will need to rename the output from *.dll to *.pyd.
setuptools-rust can be used to generate a python package and includes the commands above by default. See examples/word-count and the associated setup.py.
PyO3 is licensed under the Apache-2.0 license. Python is licensed under the Python License.