Proc macro to create .pyi file from rust implementations

[Jgfrausing]

Link to POC implementation

Motivation

Manually maintaining a .PYI for your PYO3 project sucks

Setup

Unpack

Place pyi-macros in the root of your PYO3 project.

Modify the path

Replace "INSERT_MODULE_NAME_HERE" with the name of your PYO3 module.

Dependencies

Make a dependency to the pyi_macros and add an optional feature:

[dependencies]
pyo3 = { version = "0.20.3", features = ["chrono"] }
pyi_macros = { path = "../pyi-macros",  optional = true }

[features]
pyi = ["pyi_macros"]

Usage

#[cfg_attr(feature = "pyi", pyi_macros::pyi)]
#[pyclass]
pub enum MyEnum {
    /// Some doc string
    High,
    /// Some doc string
    Low
}

#[cfg_attr(feature = "pyi", pyi_macros::pyi)]
#[pyclass]
pub struct MyClass {
    /// Some doc string
    pub value: i64
}

#[cfg_attr(feature = "pyi", pyi_macros::pyi_impl)]
#[pyclass]
pub struct MyClass {
    /// Some doc string
    pub value: i64
}

Create the PYI interface file:

> cargo build --features pyi

Know limitations

1. Not all types are implemented yet
2. This does not work well with --all-features flags for other cargo commands