Trait pyo3::conversion::FromPyObject

source ·

pub trait FromPyObject<'source>: Sized {
    // Required method
    fn extract(ob: &'source 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 Py and PyAny, which forward to this trait.

§Examples

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

Python::with_gil(|py| {
    let obj: Py<PyString> = PyString::new(py, "blah").into();

    // Straight from an owned reference
    let s: &str = obj.extract(py)?;

    // Or from a borrowed reference
    let obj: &PyString = obj.as_ref(py);
    let s: &str = obj.extract()?;
})

Note: depending on the implementation, the lifetime of the extracted result may depend on the lifetime of the obj or the prepared variable.

For example, when extracting &str from a Python byte string, the resulting string slice will point to the existing string data (lifetime: 'source). On the other hand, when extracting &str from a Python Unicode string, the preparation step will convert the string to UTF-8, and the resulting string slice will have lifetime 'prepared. Since which case applies depends on the runtime type of the Python object, both the obj and prepared variables must outlive the resulting string slice.

The trait’s conversion method takes a &PyAny argument but is called FromPyObject for historical reasons.

Required Methods§

source

fn extract(ob: &'source PyAny) -> PyResult<Self>

Extracts Self from the source PyObject.

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 IntoPy::type_output. It may be different for some types, such as Dict, to allow duck-typing: functions return Dict but take Mapping as argument.

Object Safety§

This trait is not object safe.

Trait pyo3::conversion::FromPyObject

§Examples

Required Methods§

fn extract(ob: &'source PyAny) -> PyResult<Self>

Provided Methods§

fn type_input() -> TypeInfo

Object Safety§

Implementations on Foreign Types§

impl FromPyObject<'_> for IpAddr

fn extract(obj: &PyAny) -> PyResult<Self>

impl FromPyObject<'_> for char

fn extract(obj: &PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for String

fn extract(obj: &PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl FromPyObject<'_> for OsString

fn extract(ob: &PyAny) -> PyResult<Self>

impl FromPyObject<'_> for PathBuf

fn extract(ob: &PyAny) -> PyResult<Self>

impl FromPyObject<'_> for DateTime<FixedOffset>

fn extract(ob: &PyAny) -> PyResult<DateTime<FixedOffset>>

impl FromPyObject<'_> for DateTime<Utc>

fn extract(ob: &PyAny) -> PyResult<DateTime<Utc>>

impl FromPyObject<'_> for NaiveDate

fn extract(ob: &PyAny) -> PyResult<NaiveDate>

impl FromPyObject<'_> for NaiveDateTime

fn extract(ob: &PyAny) -> PyResult<NaiveDateTime>

impl FromPyObject<'_> for NaiveTime

fn extract(ob: &PyAny) -> PyResult<NaiveTime>

impl FromPyObject<'_> for FixedOffset

fn extract(ob: &PyAny) -> PyResult<FixedOffset>

impl FromPyObject<'_> for Utc

fn extract(ob: &PyAny) -> PyResult<Utc>

impl FromPyObject<'_> for Decimal

fn extract(obj: &PyAny) -> PyResult<Self>

impl FromPyObject<'_> for Duration

fn extract(ob: &PyAny) -> PyResult<Duration>

impl<'a> FromPyObject<'a> for &'a [u8]

fn extract(obj: &'a PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'a, A> FromPyObject<'a> for SmallVec<A>where A: Array, A::Item: FromPyObject<'a>,

fn extract(obj: &'a PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'a, T> FromPyObject<'a> for Option<T>where T: FromPyObject<'a>,

fn extract(obj: &'a PyAny) -> PyResult<Self>

impl<'a, T> FromPyObject<'a> for Vec<T>where T: FromPyObject<'a>,

fn extract(obj: &'a PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'a, T, const N: usize> FromPyObject<'a> for [T; N]where T: FromPyObject<'a>,

fn extract(obj: &'a PyAny) -> PyResult<Self>

impl<'a, T: FromPyObject<'a>> FromPyObject<'a> for Cell<T>

fn extract(ob: &'a PyAny) -> PyResult<Self>

impl<'s, T0: FromPyObject<'s>> FromPyObject<'s> for (T0,)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>> FromPyObject<'s> for (T0, T1)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>, T2: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>, T2: FromPyObject<'s>, T3: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>, T2: FromPyObject<'s>, T3: FromPyObject<'s>, T4: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>, T2: FromPyObject<'s>, T3: FromPyObject<'s>, T4: FromPyObject<'s>, T5: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4, T5)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>, T2: FromPyObject<'s>, T3: FromPyObject<'s>, T4: FromPyObject<'s>, T5: FromPyObject<'s>, T6: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4, T5, T6)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>, T2: FromPyObject<'s>, T3: FromPyObject<'s>, T4: FromPyObject<'s>, T5: FromPyObject<'s>, T6: FromPyObject<'s>, T7: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4, T5, T6, T7)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'s, T0: FromPyObject<'s>, T1: FromPyObject<'s>, T2: FromPyObject<'s>, T3: FromPyObject<'s>, T4: FromPyObject<'s>, T5: FromPyObject<'s>, T6: FromPyObject<'s>, T7: FromPyObject<'s>, T8: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4, T5, T6, T7, T8)

fn extract(obj: &'s PyAny) -> PyResult<Self>

fn type_input() -> TypeInfo

impl<'a, A> FromPyObject<'a> for SmallVec<A>
where A: Array, A::Item: FromPyObject<'a>,

impl<'a, T> FromPyObject<'a> for Option<T>
where T: FromPyObject<'a>,

impl<'a, T> FromPyObject<'a> for Vec<T>
where T: FromPyObject<'a>,

impl<'a, T, const N: usize> FromPyObject<'a> for [T; N]
where T: FromPyObject<'a>,