readme: recommend maturin init

This commit is contained in:
David Hewitt 2021-11-29 18:51:21 +00:00
parent 770c02e93c
commit 6ffa508ad3
1 changed files with 39 additions and 18 deletions

View File

@ -24,15 +24,34 @@ You can use PyO3 to write a native Python module in Rust, or to embed Python in
### Using Rust from Python ### Using Rust from Python
PyO3 can be used to generate a native Python module. The easiest way to try this out for the first time is to use [`maturin`](https://github.com/PyO3/maturin). `maturin` is a tool for building and publishing Rust-based Python packages with minimal configuration. The following steps set up some files for an example Python module, install `maturin`, and then show how build and import the Python module. PyO3 can be used to generate a native Python module. The easiest way to try this out for the first time is to use [`maturin`](https://github.com/PyO3/maturin). `maturin` is a tool for building and publishing Rust-based Python packages with minimal configuration. The following steps install `maturin`, use it to generate and build a new Python package, and then launch Python to import and execute a function from the package.
First, create a new folder (let's call it `string_sum`) containing the following two files: First, follow the commands below to create a new directory containing a new Python `virtualenv`, and install `maturin` into the virtualenv using Python's package manager, `pip`:
```bash
# (replace string_sum with the desired package name)
$ mkdir string_sum
$ cd string_sum
$ python -m venv .env
$ source .env/bin/activate
$ pip install maturin
```
Still inside this `string_sum` directory, now run `maturin init`. This will generate the new package source. When given the choice of bindings to use, select pyo3 bindings:
```bash
$ maturin init
✔ 🤷 What kind of bindings to use? · pyo3
✨ Done! New project created string_sum
```
The most important files generated by this command are `Cargo.toml` and `lib.rs`, which will look roughly like the following:
**`Cargo.toml`** **`Cargo.toml`**
```toml ```toml
[package] [package]
name = "string-sum" name = "string_sum"
version = "0.1.0" version = "0.1.0"
edition = "2018" edition = "2018"
@ -45,9 +64,8 @@ name = "string_sum"
# crate-type = ["cdylib", "rlib"] # crate-type = ["cdylib", "rlib"]
crate-type = ["cdylib"] crate-type = ["cdylib"]
[dependencies.pyo3] [dependencies]
version = "0.15.1" pyo3 = { version = "0.15.1", features = ["extension-module"] }
features = ["extension-module"]
``` ```
**`src/lib.rs`** **`src/lib.rs`**
@ -67,21 +85,11 @@ fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
#[pymodule] #[pymodule]
fn string_sum(_py: Python, m: &PyModule) -> PyResult<()> { fn string_sum(_py: Python, m: &PyModule) -> PyResult<()> {
m.add_function(wrap_pyfunction!(sum_as_string, m)?)?; m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
Ok(()) Ok(())
} }
``` ```
With those two files in place, now `maturin` needs to be installed. This can be done using Python's package manager `pip`. First, load up a new Python `virtualenv`, and install `maturin` into it: Finally, run `maturin develop`. This will build the package and install it into the Python virtualenv previously created and activated. The package is then ready to be used from `python`:
```bash
$ cd string_sum
$ python -m venv .env
$ source .env/bin/activate
$ pip install maturin
```
Now build and execute the module:
```bash ```bash
$ maturin develop $ maturin develop
@ -92,7 +100,20 @@ $ python
'25' '25'
``` ```
As well as with `maturin`, it is possible to build using [`setuptools-rust`](https://github.com/PyO3/setuptools-rust) or [manually](https://pyo3.rs/latest/building_and_distribution.html#manual-builds). Both offer more flexibility than `maturin` but require further configuration. To make changes to the package, just edit the Rust source code and then re-run `maturin develop` to recompile.
To run this all as a single copy-and-paste, use the bash script below (replace `string_sum` in the first command with the desired package name):
```bash
mkdir string_sum && cd "$_"
python -m venv .env
source .env/bin/activate
pip install maturin
maturin init --bindings pyo3
maturin develop
```
As well as with `maturin`, it is possible to build using [`setuptools-rust`](https://github.com/PyO3/setuptools-rust) or [manually](https://pyo3.rs/latest/building_and_distribution.html#manual-builds). Both offer more flexibility than `maturin` but require more configuration to get started.
### Using Python from Rust ### Using Python from Rust