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§

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

Extracts Self from the source PyObject.

Provided Methods§

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fn type_input() -> TypeInfo

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.

Implementations on Foreign Types§

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impl<'source> FromPyObject<'source> for NonZeroI32

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

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fn type_input() -> TypeInfo

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impl<'source, K, S> FromPyObject<'source> for HashSet<K, S>where K: FromPyObject<'source> + Eq + Hash, S: BuildHasher + Default,

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

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fn type_input() -> TypeInfo

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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)

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impl FromPyObject<'_> for FixedOffset

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

Convert python tzinfo to rust FixedOffset.

Note that the conversion will result in precision lost in microseconds as chrono offset does not supports microseconds.

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impl FromPyObject<'_> for Utc

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impl<'source> FromPyObject<'source> for i64

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for &'source str

Allows extracting strings from Python objects. Accepts Python str and unicode objects.

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for u16

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for BigUint

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

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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>, T9: FromPyObject<'s>, T10: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)

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impl<'source> FromPyObject<'source> for NonZeroI8

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

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fn type_input() -> TypeInfo

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

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impl<'source, K, V, S> FromPyObject<'source> for HashMap<K, V, S>where K: FromPyObject<'source> + Eq + Hash, V: FromPyObject<'source>, S: BuildHasher + Default,

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fn extract(ob: &'source PyAny) -> Result<Self, PyErr>

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impl<'source> FromPyObject<'source> for u8

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for u128

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impl FromPyObject<'_> for IpAddr

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

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

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impl FromPyObject<'_> for Duration

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impl<'source> FromPyObject<'source> for usize

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

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fn type_input() -> TypeInfo

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impl FromPyObject<'_> for DateTime<Utc>

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impl<'source> FromPyObject<'source> for u64

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

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

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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)

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impl<'source, K, V, S> FromPyObject<'source> for IndexMap<K, V, S>where K: FromPyObject<'source> + Eq + Hash, V: FromPyObject<'source>, S: BuildHasher + Default,

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fn extract(ob: &'source PyAny) -> Result<Self, PyErr>

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impl FromPyObject<'_> for char

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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)

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impl FromPyObject<'_> for OsString

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

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impl<'source> FromPyObject<'source> for BigInt

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

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impl<'source> FromPyObject<'source> for bool

Converts a Python bool to a Rust bool.

Fails with TypeError if the input is not a Python bool.

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for NonZeroIsize

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

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fn type_input() -> TypeInfo

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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)

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

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

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

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impl<'source> FromPyObject<'source> for NonZeroU32

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for NonZeroI64

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

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fn type_input() -> TypeInfo

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impl FromPyObject<'_> for NaiveDate

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impl<'source> FromPyObject<'source> for Complex<f32>

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fn extract(obj: &'source PyAny) -> PyResult<Complex<f32>>

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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)

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

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

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

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impl<'source> FromPyObject<'source> for NonZeroI16

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

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fn type_input() -> TypeInfo

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impl<'source, K> FromPyObject<'source> for BTreeSet<K>where K: FromPyObject<'source> + Ord,

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for i128

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

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impl<'source> FromPyObject<'source> for u32

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for NonZeroI128

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

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fn type_input() -> TypeInfo

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impl<'source, K, S> FromPyObject<'source> for HashSet<K, S>where K: FromPyObject<'source> + Eq + Hash, S: BuildHasher + Default,

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

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impl<'source> FromPyObject<'source> for NonZeroU8

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for isize

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

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fn type_input() -> TypeInfo

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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>, T9: FromPyObject<'s>, T10: FromPyObject<'s>, T11: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11)

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impl<'source> FromPyObject<'source> for NonZeroU16

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

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fn type_input() -> TypeInfo

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impl FromPyObject<'_> for Decimal

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

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impl<'source> FromPyObject<'source> for Cow<'source, [u8]>

Special-purpose trait impl to efficiently handle both bytes and bytearray

If the source object is a bytes object, the Cow will be borrowed and pointing into the source object, and no copying or heap allocations will happen. If it is a bytearray, its contents will be copied to an owned Cow.

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

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impl<'source> FromPyObject<'source> for Complex<f64>

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fn extract(obj: &'source PyAny) -> PyResult<Complex<f64>>

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impl<'source> FromPyObject<'source> for NonZeroU64

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

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fn type_input() -> TypeInfo

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impl<'source, K, V, S> FromPyObject<'source> for HashMap<K, V, S>where K: FromPyObject<'source> + Eq + Hash, V: FromPyObject<'source>, S: BuildHasher + Default,

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fn extract(ob: &'source PyAny) -> Result<Self, PyErr>

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for NonZeroUsize

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

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fn type_input() -> TypeInfo

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impl<'source, K, V> FromPyObject<'source> for BTreeMap<K, V>where K: FromPyObject<'source> + Ord, V: FromPyObject<'source>,

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fn extract(ob: &'source PyAny) -> Result<Self, PyErr>

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for f64

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for f32

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

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fn type_input() -> TypeInfo

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impl FromPyObject<'_> for NaiveTime

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impl FromPyObject<'_> for PathBuf

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

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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>, T9: FromPyObject<'s>> FromPyObject<'s> for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9)

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impl<'source> FromPyObject<'source> for i32

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

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fn type_input() -> TypeInfo

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impl<'source> FromPyObject<'source> for i16

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

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fn type_input() -> TypeInfo

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

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impl FromPyObject<'_> for String

Allows extracting strings from Python objects. Accepts Python str and unicode objects.

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impl<'source, L, R> FromPyObject<'source> for Either<L, R>where L: FromPyObject<'source>, R: FromPyObject<'source>,

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

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fn type_input() -> TypeInfo

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impl FromPyObject<'_> for DateTime<FixedOffset>

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impl<'source> FromPyObject<'source> for i8

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

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fn type_input() -> TypeInfo

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

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impl FromPyObject<'_> for NaiveDateTime

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impl<'source> FromPyObject<'source> for NonZeroU128

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

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fn type_input() -> TypeInfo

Implementors§

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impl<'a, T> FromPyObject<'a> for &'a PyCell<T>where T: PyClass,

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impl<'a, T> FromPyObject<'a> for Py<T>where T: PyTypeInfo, &'a T::AsRefTarget: FromPyObject<'a>, T::AsRefTarget: 'a + AsPyPointer,

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impl<'a, T> FromPyObject<'a> for PyRef<'a, T>where T: PyClass,

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impl<'a, T> FromPyObject<'a> for PyRefMut<'a, T>where T: PyClass<Frozen = False>,

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impl<'a, T> FromPyObject<'a> for Twhere T: PyClass + Clone,

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impl<'py> FromPyObject<'py> for &'py CancelledError

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impl<'py> FromPyObject<'py> for &'py IncompleteReadError

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impl<'py> FromPyObject<'py> for &'py InvalidStateError

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impl<'py> FromPyObject<'py> for &'py LimitOverrunError

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impl<'py> FromPyObject<'py> for &'py QueueEmpty

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impl<'py> FromPyObject<'py> for &'py QueueFull

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impl<'py> FromPyObject<'py> for &'py TimeoutError

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impl<'py> FromPyObject<'py> for &'py gaierror

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impl<'py> FromPyObject<'py> for &'py herror

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impl<'py> FromPyObject<'py> for &'py timeout

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impl<'py> FromPyObject<'py> for &'py PyArithmeticError

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impl<'py> FromPyObject<'py> for &'py PyAssertionError

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impl<'py> FromPyObject<'py> for &'py PyAttributeError

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impl<'py> FromPyObject<'py> for &'py PyBaseException

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impl<'py> FromPyObject<'py> for &'py PyBlockingIOError

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impl<'py> FromPyObject<'py> for &'py PyBrokenPipeError

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impl<'py> FromPyObject<'py> for &'py PyBufferError

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impl<'py> FromPyObject<'py> for &'py PyBytesWarning

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impl<'py> FromPyObject<'py> for &'py PyChildProcessError

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impl<'py> FromPyObject<'py> for &'py PyConnectionAbortedError

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impl<'py> FromPyObject<'py> for &'py PyConnectionError

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impl<'py> FromPyObject<'py> for &'py PyConnectionRefusedError

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impl<'py> FromPyObject<'py> for &'py PyConnectionResetError

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impl<'py> FromPyObject<'py> for &'py PyDeprecationWarning

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impl<'py> FromPyObject<'py> for &'py PyEOFError

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impl<'py> FromPyObject<'py> for &'py PyEnvironmentError

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impl<'py> FromPyObject<'py> for &'py PyException

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impl<'py> FromPyObject<'py> for &'py PyFileExistsError

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impl<'py> FromPyObject<'py> for &'py PyFileNotFoundError

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impl<'py> FromPyObject<'py> for &'py PyFloatingPointError

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impl<'py> FromPyObject<'py> for &'py PyFutureWarning

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impl<'py> FromPyObject<'py> for &'py PyGeneratorExit

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impl<'py> FromPyObject<'py> for &'py PyIOError

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impl<'py> FromPyObject<'py> for &'py PyImportError

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impl<'py> FromPyObject<'py> for &'py PyImportWarning

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impl<'py> FromPyObject<'py> for &'py PyIndexError

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impl<'py> FromPyObject<'py> for &'py PyInterruptedError

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impl<'py> FromPyObject<'py> for &'py PyIsADirectoryError

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impl<'py> FromPyObject<'py> for &'py PyKeyError

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impl<'py> FromPyObject<'py> for &'py PyKeyboardInterrupt

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impl<'py> FromPyObject<'py> for &'py PyLookupError

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impl<'py> FromPyObject<'py> for &'py PyMemoryError

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impl<'py> FromPyObject<'py> for &'py PyModuleNotFoundError

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impl<'py> FromPyObject<'py> for &'py PyNameError

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impl<'py> FromPyObject<'py> for &'py PyNotADirectoryError

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impl<'py> FromPyObject<'py> for &'py PyNotImplementedError

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impl<'py> FromPyObject<'py> for &'py PyOSError

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impl<'py> FromPyObject<'py> for &'py PyOverflowError

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impl<'py> FromPyObject<'py> for &'py PyPendingDeprecationWarning

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impl<'py> FromPyObject<'py> for &'py PyPermissionError

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impl<'py> FromPyObject<'py> for &'py PyProcessLookupError

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impl<'py> FromPyObject<'py> for &'py PyRecursionError

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impl<'py> FromPyObject<'py> for &'py PyReferenceError

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impl<'py> FromPyObject<'py> for &'py PyResourceWarning

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impl<'py> FromPyObject<'py> for &'py PyRuntimeError

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impl<'py> FromPyObject<'py> for &'py PyRuntimeWarning

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impl<'py> FromPyObject<'py> for &'py PyStopAsyncIteration

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impl<'py> FromPyObject<'py> for &'py PyStopIteration

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impl<'py> FromPyObject<'py> for &'py PySyntaxError

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impl<'py> FromPyObject<'py> for &'py PySyntaxWarning

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impl<'py> FromPyObject<'py> for &'py PySystemError

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impl<'py> FromPyObject<'py> for &'py PySystemExit

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impl<'py> FromPyObject<'py> for &'py PyTimeoutError

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impl<'py> FromPyObject<'py> for &'py PyTypeError

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impl<'py> FromPyObject<'py> for &'py PyUnboundLocalError

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impl<'py> FromPyObject<'py> for &'py PyUnicodeDecodeError

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impl<'py> FromPyObject<'py> for &'py PyUnicodeEncodeError

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impl<'py> FromPyObject<'py> for &'py PyUnicodeError

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impl<'py> FromPyObject<'py> for &'py PyUnicodeTranslateError

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impl<'py> FromPyObject<'py> for &'py PyUnicodeWarning

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impl<'py> FromPyObject<'py> for &'py PyUserWarning

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impl<'py> FromPyObject<'py> for &'py PyValueError

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impl<'py> FromPyObject<'py> for &'py PyWarning

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impl<'py> FromPyObject<'py> for &'py PyZeroDivisionError

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impl<'py> FromPyObject<'py> for &'py PanicException

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impl<'py> FromPyObject<'py> for &'py PyAny

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impl<'py> FromPyObject<'py> for &'py PyBool

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impl<'py> FromPyObject<'py> for &'py PyByteArray

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impl<'py> FromPyObject<'py> for &'py PyBytes

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impl<'py> FromPyObject<'py> for &'py PyCFunction

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impl<'py> FromPyObject<'py> for &'py PyCapsule

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impl<'py> FromPyObject<'py> for &'py PyCode

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impl<'py> FromPyObject<'py> for &'py PyComplex

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impl<'py> FromPyObject<'py> for &'py PyDate

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impl<'py> FromPyObject<'py> for &'py PyDateTime

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impl<'py> FromPyObject<'py> for &'py PyDelta

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impl<'py> FromPyObject<'py> for &'py PyDict

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impl<'py> FromPyObject<'py> for &'py PyDictItems

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impl<'py> FromPyObject<'py> for &'py PyDictKeys

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impl<'py> FromPyObject<'py> for &'py PyDictValues

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impl<'py> FromPyObject<'py> for &'py PyEllipsis

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impl<'py> FromPyObject<'py> for &'py PyFloat

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impl<'py> FromPyObject<'py> for &'py PyFrame

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impl<'py> FromPyObject<'py> for &'py PyFrozenSet

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impl<'py> FromPyObject<'py> for &'py PyFunction

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impl<'py> FromPyObject<'py> for &'py PyIterator

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impl<'py> FromPyObject<'py> for &'py PyList

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impl<'py> FromPyObject<'py> for &'py PyLong

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impl<'py> FromPyObject<'py> for &'py PyMapping

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impl<'py> FromPyObject<'py> for &'py PyMemoryView

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impl<'py> FromPyObject<'py> for &'py PyModule

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impl<'py> FromPyObject<'py> for &'py PyNone

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impl<'py> FromPyObject<'py> for &'py PyNotImplemented

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impl<'py> FromPyObject<'py> for &'py PySequence

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impl<'py> FromPyObject<'py> for &'py PySet

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impl<'py> FromPyObject<'py> for &'py PySlice

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impl<'py> FromPyObject<'py> for &'py PyString

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impl<'py> FromPyObject<'py> for &'py PySuper

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impl<'py> FromPyObject<'py> for &'py PyTime

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impl<'py> FromPyObject<'py> for &'py PyTraceback

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impl<'py> FromPyObject<'py> for &'py PyTuple

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impl<'py> FromPyObject<'py> for &'py PyType

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impl<'py> FromPyObject<'py> for &'py PyTzInfo

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impl<'source, T: Element> FromPyObject<'source> for PyBuffer<T>