Generates CPython bindings for Interoptopus.

Usage

Assuming you have written a crate containing your FFI logic called example_library_ffi and want to generate CPython bindings for Python 3.7+, follow the instructions below.

Inside Your Library

Add Interoptopus attributes to the library you have written, and define an inventory function listing all symbols you wish to export. An overview of all supported constructs can be found in the reference project.

```rust use interoptopus::{ffifunction, ffitype, Inventory, InventoryBuilder, function};

[ffi_type]

[repr(C)]

pub struct Vec2 { pub x: f32, pub y: f32, }

[ffi_function]

[no_mangle]

pub extern "C" fn my_function(input: Vec2) -> Vec2 { input }

pub fn myinventory() -> Inventory { InventoryBuilder::new() .register(function!(myfunction)) .inventory() } ```

Add these to your Cargo.toml so the attributes and the binding generator can be found (replace ... with the latest version):

```toml [lib] crate-type = ["cdylib", "rlib"]

[dependencies] interoptopus = "..." interoptopusbackendcpython = "..." ```

Create a unit test in tests/bindings.rs which will generate your bindings when run with cargo test. In real projects you might want to add this code to another crate instead:

```rust use interoptopus::util::NamespaceMappings; use interoptopus::{Error, Interop};

[test]

fn bindingscpythoncffi() -> Result<(), Error> { use interoptopusbackendcpython::{Config, Generator};

let library = example_library_ffi::my_inventory();

Generator::new(Config::default(), library)
    .write_file("bindings/python/example_library.py")?;

Ok(())

} ```

Now run cargo test.

If anything is unclear you can find a working sample on Github.

Generated Output

The output below is what this backend might generate. Have a look at the [Config] struct if you want to customize something. If you really don't like how something is generated it is easy to create your own.

```python from future import annotations import ctypes import typing

T = typing.TypeVar("T") c_lib = None

def initlib(path): """Initializes the native library. Must be called at least once before anything else.""" global clib clib = ctypes.cdll.LoadLibrary(path) clib.myfunction.argtypes = [Vec2] clib.my_function.restype = Vec2

def myfunction(input: Vec2) -> Vec2: return clib.my_function(input)

TRUE = ctypes.cuint8(1) FALSE = ctypes.cuint8(0)

class Vec2(ctypes.Structure): # These fields represent the underlying C data layout fields = [ ("x", ctypes.cfloat), ("y", ctypes.cfloat), ]

def __init__(self, x: float = None, y: float = None):
    if x is not None:
        self.x = x
    if y is not None:
        self.y = y

@property
def x(self) -> float:
    return ctypes.Structure.__get__(self, "x")

@x.setter
def x(self, value: float):
    return ctypes.Structure.__set__(self, "x", value)

@property
def y(self) -> float:
    return ctypes.Structure.__get__(self, "y")

@y.setter
def y(self, value: float):
    return ctypes.Structure.__set__(self, "y", value)

```