Struct PyFixedString

#[repr(transparent)]
pub struct PyFixedString<const N: usize>(pub [Py_UCS1; N]);

A newtype wrapper around [[u8; N]][Py_UCS1] to handle byte scalars while satisfying coherence.

Note that when creating arrays of ASCII strings without an explicit dtype, NumPy will automatically determine the smallest possible array length at runtime.

For example,

array = numpy.array([b"foo", b"bar", b"foobar"])

yields S6 for array.dtype.

On the Rust side however, the length N of PyFixedString<N> must always be given explicitly and as a compile-time constant. For this work reliably, the Python code should set the dtype explicitly, e.g.

numpy.array([b"foo", b"bar", b"foobar"], dtype='S12')

always matching PyArray1<PyFixedString<12>>.

Example

use numpy::{PyArray1, PyUntypedArrayMethods, PyFixedString};

let array = PyArray1::<PyFixedString<3>>::from_vec(py, vec![[b'f', b'o', b'o'].into()]);

assert!(array.dtype().to_string().contains("S3"));

Tuple Fields

0: [Py_UCS1; N]

Trait Implementations

impl<const N: usize> Clone for PyFixedString<N>

fn clone(&self) -> PyFixedString<N>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<const N: usize> Debug for PyFixedString<N>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<const N: usize> Display for PyFixedString<N>

fn fmt(&self, fmt: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<const N: usize> Element for PyFixedString<N>

const IS_COPY: bool = true

Flag that indicates whether this type is trivially copyable.

fn get_dtype(py: Python<'_>) -> Bound<'_, PyArrayDescr>

Returns the associated type descriptor (“dtype”) for the given element type.

fn clone_ref(&self, _py: Python<'_>) -> Self

Create a clone of the value while the GIL is guaranteed to be held.

fn vec_from_slice(_py: Python<'_>, slc: &[Self]) -> Vec<Self>

Create an owned copy of the slice while the GIL is guaranteed to be held.

fn array_from_view<D>( _py: Python<'_>, view: ArrayView<'_, Self, D>, ) -> Array<Self, D>

where D: Dimension,

Create an owned copy of the array while the GIL is guaranteed to be held.

fn get_dtype_bound(py: Python<'_>) -> Bound<'_, PyArrayDescr>

👎Deprecated since 0.23.0: renamed to Element::get_dtype

Deprecated name for Element::get_dtype.

impl<const N: usize> From<[u8; N]> for PyFixedString<N>

fn from(val: [Py_UCS1; N]) -> Self

Converts to this type from the input type.

impl<const N: usize> Hash for PyFixedString<N>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<const N: usize> Ord for PyFixedString<N>

fn cmp(&self, other: &PyFixedString<N>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<const N: usize> PartialEq for PyFixedString<N>

fn eq(&self, other: &PyFixedString<N>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const N: usize> PartialOrd for PyFixedString<N>

fn partial_cmp(&self, other: &PyFixedString<N>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<const N: usize> Copy for PyFixedString<N>

impl<const N: usize> Eq for PyFixedString<N>

impl<const N: usize> StructuralPartialEq for PyFixedString<N>