Trait IntoPy

Source

pub trait IntoPy<T>: Sized {
    // Required method
    fn into_py(self, py: Python<'_>) -> T;
}

👎Deprecated since 0.23.0: IntoPy is going to be replaced by IntoPyObject. See the migration guide (https://pyo3.rs/v0.23.0/migration) for more information.

Expand description

Defines a conversion from a Rust type to a Python object.

It functions similarly to std’s Into trait, but requires a GIL token as an argument. Many functions and traits internal to PyO3 require this trait as a bound, so a lack of this trait can manifest itself in different error messages.

§Examples

§With `#[pyclass]`

The easiest way to implement IntoPy is by exposing a struct as a native Python object by annotating it with #[pyclass].

use pyo3::prelude::*;

#[pyclass]
struct Number {
    #[pyo3(get, set)]
    value: i32,
}

Python code will see this as an instance of the Number class with a value attribute.

§Conversion to a Python object

However, it may not be desirable to expose the existence of Number to Python code. IntoPy allows us to define a conversion to an appropriate Python object.

#![allow(deprecated)]
use pyo3::prelude::*;

struct Number {
    value: i32,
}

impl IntoPy<PyObject> for Number {
    fn into_py(self, py: Python<'_>) -> PyObject {
        // delegates to i32's IntoPy implementation.
        self.value.into_py(py)
    }
}

Python code will see this as an int object.

§Dynamic conversion into Python objects.

It is also possible to return a different Python object depending on some condition. This is useful for types like enums that can carry different types.

#![allow(deprecated)]
use pyo3::prelude::*;

enum Value {
    Integer(i32),
    String(String),
    None,
}

impl IntoPy<PyObject> for Value {
    fn into_py(self, py: Python<'_>) -> PyObject {
        match self {
            Self::Integer(val) => val.into_py(py),
            Self::String(val) => val.into_py(py),
            Self::None => py.None(),
        }
    }
}

Python code will see this as any of the int, string or None objects.

Required Methods§

Source

fn into_py(self, py: Python<'_>) -> T

👎Deprecated since 0.23.0: IntoPy is going to be replaced by IntoPyObject. See the migration guide (https://pyo3.rs/v0.23.0/migration) for more information.

Performs the conversion.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Trait IntoPyCopy item path

§Examples

§With #[pyclass]

§Conversion to a Python object

§Dynamic conversion into Python objects.

Required Methods§

fn into_py(self, py: Python<'_>) -> T

Dyn Compatibility§

Implementations on Foreign Types§

impl IntoPy<Py<PyAny>> for &str

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for &String

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for &OsStr

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for &OsString

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for &Path

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for &PathBuf

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for &[u8]

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for Cow<'_, str>

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for Cow<'_, OsStr>

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for Cow<'_, Path>

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for Cow<'_, [u8]>

fn into_py(self, py: Python<'_>) -> Py<PyAny>

impl IntoPy<Py<PyAny>> for IpAddr

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for bool

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for char

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for f32

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for f64

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for i8

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for i16

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for i32

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for i64

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for i128

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for isize

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for u8

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for u16

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for u32

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for u64

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for u128

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for ()

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for usize

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for String

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for Duration

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for OsString

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for PathBuf

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for SystemTime

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for NaiveDate

fn into_py(self, py: Python<'_>) -> PyObject

impl IntoPy<Py<PyAny>> for NaiveDateTime

Trait IntoPy

§With `#[pyclass]`

impl<A> IntoPy<Py<PyAny>> for SmallVec<A>
where A: Array, A::Item: IntoPy<PyObject>,

impl<K> IntoPy<Py<PyAny>> for BTreeSet<K>
where K: IntoPy<PyObject> + Ord,