Rust bindings for Python. 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 1.34.0-nightly 2019-02-06.
You can either write a native python module in rust or use python from a rust binary.
On some OSs, you need some additional packages.
E.g. if you are on Ubuntu18.04, please run
Using rust from python
PyO3 can be used to generate a native python module.
 = "string-sum" = "0.1.0" = "2018"  = "string_sum" = ["cdylib"]  = "0.6.0-alpha.4" = ["extension-module"]
// Not required when using Rust 2018 extern crate pyo3; use *; use wrap_pyfunction; /// Formats the sum of two numbers as string /// This module is a python module implemented in Rust.
On windows and linux, you can build normally with
cargo build --release. On macOS, 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:
 = [ "-C", "link-arg=-undefined", "-C", "link-arg=dynamic_lookup", ]
For developing, you can copy and rename the shared library from the target folder: On macOS, rename
string_sum.so, on windows
string_sum.pyd and on linux
string_sum.so. Then open a python shell in the same folder and you'll be able to
To build, test and publish your crate as python module, you can use pyo3-pack or setuptools-rust. You can find an example for setuptools-rust in examples/word-count, while pyo3-pack should work on your crate without any configuration.
Using python from rust
pyo3 this to your
 = "0.6.0-alpha.4"
Example program displaying the value of
// Not required when using Rust 2018 extern crate pyo3; use *; use IntoPyDict;
Examples and tooling
- examples/word-count Counting the occurrences of a word in a text file
- hyperjson A hyper-fast Python module for reading/writing JSON data using Rust's serde-json
- rust-numpy Rust binding of NumPy C-API
- html-py-ever Using html5ever through kuchiki to speed up html parsing and css-selecting.
- pyo3-built Simple macro to expose metadata obtained with the
builtcrate as a
- point-process High level API for pointprocesses as a Python library
- autopy A simple, cross-platform GUI automation library for Python and Rust.
- orjson Fast Python JSON library
PyO3 is licensed under the Apache-2.0 license. Python is licensed under the Python License.