Trait FromPyObject

Source

pub trait FromPyObject<'py>: Sized {
    const INPUT_TYPE: &'static str = "typing.Any";

    // Required method
    fn extract_bound(ob: &Bound<'py, PyAny>) -> PyResult<Self>;

    // Provided method
    fn type_input() -> TypeInfo { ... }
}

Expand description

Extract a type from a Python object.

Normal usage is through the extract methods on Bound and Py, which forward to this trait.

§Examples

use pyo3::prelude::*;
use pyo3::types::PyString;

Python::attach(|py| {
    // Calling `.extract()` on a `Bound` smart pointer
    let obj: Bound<'_, PyString> = PyString::new(py, "blah");
    let s: String = obj.extract()?;

    // Calling `.extract(py)` on a `Py` smart pointer
    let obj: Py<PyString> = obj.unbind();
    let s: String = obj.extract(py)?;
})

During the migration of PyO3 from the “GIL Refs” API to the Bound<T> smart pointer, this trait has two methods extract and extract_bound which are defaulted to call each other. To avoid infinite recursion, implementors must implement at least one of these methods. The recommendation is to implement extract_bound and leave extract as the default implementation.

Provided Associated Constants§

Source

const INPUT_TYPE: &'static str = "typing.Any"

Available on crate feature experimental-inspect only.

Provides the type hint information for this type when it appears as an argument.

For example, Vec<u32> would be collections.abc.Sequence[int]. The default value is typing.Any, which is correct for any type.

Required Methods§

Source

fn extract_bound(ob: &Bound<'py, PyAny>) -> PyResult<Self>

Extracts Self from the bound smart pointer obj.

Implementors are encouraged to implement this method and leave extract defaulted, as this will be most compatible with PyO3’s future API.

Provided Methods§

Source

fn type_input() -> TypeInfo

Available on crate feature experimental-inspect only.

Extracts the type hint information for this type when it appears as an argument.

For example, Vec<u32> would return Sequence[int]. The default implementation returns Any, which is correct for any type.

For most types, the return value for this method will be identical to that of IntoPyObject::type_output. It may be different for some types, such as Dict, to allow duck-typing: functions return Dict but take Mapping as argument.

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 FromPyObject Copy item path

§Examples

Provided Associated Constants§

const INPUT_TYPE: &'static str = "typing.Any"

Required Methods§

fn extract_bound(ob: &Bound<'py, PyAny>) -> PyResult<Self>

Provided Methods§

fn type_input() -> TypeInfo

Dyn Compatibility§

Implementations on Foreign Types§

impl FromPyObject<'_> for IpAddr

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for Tz

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<Tz>

impl FromPyObject<'_> for bool

const INPUT_TYPE: &'static str = "bool"

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for char

const INPUT_TYPE: &'static str = "str"

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for i128

const INPUT_TYPE: &'static str = "int"

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<i128>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for u8

const INPUT_TYPE: &'static str = "int"

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for u64

const INPUT_TYPE: &'static str = "int"

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<u64>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for u128

const INPUT_TYPE: &'static str = "int"

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<u128>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for usize

const INPUT_TYPE: &'static str = u64::INPUT_TYPE

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for String

const INPUT_TYPE: &'static str = "str"

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for Duration

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for OsString

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for PathBuf

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for SystemTime

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for BigDecimal

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for Bytes

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for NaiveDate

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<NaiveDate>

impl FromPyObject<'_> for NaiveDateTime

fn extract_bound(dt: &Bound<'_, PyAny>) -> PyResult<NaiveDateTime>

impl FromPyObject<'_> for NaiveTime

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<NaiveTime>

impl FromPyObject<'_> for FixedOffset

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<FixedOffset>

impl FromPyObject<'_> for Local

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<Local>

impl FromPyObject<'_> for Utc

fn extract_bound(ob: &Bound<'_, PyAny>) -> PyResult<Utc>

impl FromPyObject<'_> for Complex<f32>

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Complex<f32>>

impl FromPyObject<'_> for Complex<f64>

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Complex<f64>>

impl FromPyObject<'_> for NotNan<f32>

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for NotNan<f64>

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

impl FromPyObject<'_> for OrderedFloat<f32>

fn extract_bound(obj: &Bound<'_, PyAny>) -> PyResult<Self>

Trait FromPyObject