使用rust语言创建python模块（pyo3+maturin）

1. 首先使用conda创建python虚拟环境（已创建的可省略）

>conda create --prefix=E:\python_envs\rust_python python=3.11

2. 激活python虚拟环境

conda activate rust_python

3. 安装maturin

pip install maturin

4. 创建rust项目

>cd  E:\python_envs\rust_python
>mkdir rust
>cd rust
>maturin init
✔ 🤷 Which kind of bindings to use?
  📖 Documentation: https://maturin.rs/bindings.html · pyo3
  ✨ Done! Initialized project E:\python_envs\rust_python\rust

选择pyo3，将在E:\python_envs\rust_python\rust\创建rust项目

5. 在Visual Studio Code中打开rust项目并编辑 

以pyo官方示例为例，修改Cargo.toml文件内容如下：

[package]
name = "rust"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[lib]
# The name of the native library. This is the name which will be used in Python to import the
# library (i.e. `import string_sum`). If you change this, you must also change the name of the
# `#[pymodule]` in `src/lib.rs`.
name = "rust_string_sum"
# "cdylib" is necessary to produce a shared library for Python to import from.
#
# Downstream Rust code (including code in `bin/`, `examples/`, and `tests/`) will not be able
# to `use string_sum;` unless the "rlib" or "lib" crate type is also included, e.g.:
# crate-type = ["cdylib", "rlib"]
crate-type = ["cdylib"]

[dependencies]
pyo3 = { version = "0.23.3", features = ["extension-module"] }

保存后，VS Code的rust-analyzer插件将自动运行Cargo下载pyo3及相关依赖包（过程可能会比较长）。

 修改src/lib.rs文件，内容如下：

use pyo3::prelude::*;

/// Formats the sum of two numbers as string.
#[pyfunction]
fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
    Ok((a + b).to_string())
}

/// A Python module implemented in Rust. The name of this function must match
/// the `lib.name` setting in the `Cargo.toml`, else Python will not be able to
/// import the module.
#[pymodule]
fn rust_string_sum(m: &Bound<'_, PyModule>) -> PyResult<()> {
    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
    Ok(())
}

6. 使用maturin编译项目并安装到python环境

>maturin develop
  Downloaded portable-atomic v1.10.0
  Downloaded 1 crate (174.8 KB) in 18.31s
🔗 Found pyo3 bindings
🐍 Found CPython 3.11 at E:\python_envs\rust_python\python.exe
📡 Using build options features from pyproject.toml
   Compiling once_cell v1.20.2
   Compiling cfg-if v1.0.0
   Compiling unindent v0.2.3
   Compiling libc v0.2.168
   Compiling pyo3-build-config v0.23.3
   Compiling memoffset v0.9.1
   Compiling pyo3-macros-backend v0.23.3
   Compiling pyo3-ffi v0.23.3
   Compiling pyo3 v0.23.3
   Compiling pyo3-macros v0.23.3
   Compiling rust v0.1.0 (E:\python_envs\rust_python\rust)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.56s
📦 Built wheel for CPython 3.11 to C:\Users\yislwll\AppData\Local\Temp\.tmpRW3z8Z\rust-0.1.0-cp311-cp311-win_amd64.whl
✏️  Setting installed package as editable
🛠 Installed  rust-0.1.0

7. 在python虚拟环境中调用rust新建的模块

(E:\python_envs\rust_python) E:\python_envs\rust_python\rust>python
Python 3.11.7 | packaged by conda-forge | (main, Dec 23 2023, 14:27:59) [MSC v.1937 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import rust_string_sum
>>> rust_string_sum.sum_as_string(5,20)
'25'
>>>