Struct numpy::PyArrayDescr

pub struct PyArrayDescr(_);

Binding of numpy.dtype.

Example

use pyo3::types::IntoPyDict;
pyo3::Python::with_gil(|py| {
    let locals = [("np", numpy::get_array_module(py).unwrap())].into_py_dict(py);
    let dtype: &numpy::PyArrayDescr = py
        .eval("np.array([1, 2, 3.0]).dtype", Some(locals), None)
        .unwrap()
        .downcast()
        .unwrap();
    assert_eq!(dtype.get_datatype().unwrap(), numpy::DataType::Float64);
});

Implementations

impl PyArrayDescr

pub fn as_dtype_ptr(&self) -> *mut PyArray_Descr

Returns self as *mut PyArray_Descr.

pub fn get_type(&self) -> &PyType

Returns the internal PyType that this dtype holds.

Example

pyo3::Python::with_gil(|py| {
   let array = numpy::PyArray::from_vec(py, vec![0.0, 1.0, 2.0f64]);
   let dtype = array.dtype();
   assert_eq!(dtype.get_type().name().unwrap().to_string(), "float64");
});

pub fn get_datatype(&self) -> Option<DataType>

Returns the data type as DataType enum.

Methods from Deref<Target = PyAny>

pub fn downcast<T>(&self) -> Result<&T, PyDowncastError<'_>> where
    T: for<'py> PyTryFrom<'py>, 

Convert this PyAny to a concrete Python type.

pub fn hasattr<N>(&self, attr_name: N) -> Result<bool, PyErr> where
    N: ToPyObject, 

Determines whether this object has the given attribute.

This is equivalent to the Python expression hasattr(self, attr_name).

pub fn getattr<N>(&self, attr_name: N) -> Result<&PyAny, PyErr> where
    N: ToPyObject, 

Retrieves an attribute value.

This is equivalent to the Python expression self.attr_name.

pub fn setattr<N, V>(&self, attr_name: N, value: V) -> Result<(), PyErr> where
    V: ToBorrowedObject,
    N: ToBorrowedObject, 

Sets an attribute value.

This is equivalent to the Python expression self.attr_name = value.

pub fn delattr<N>(&self, attr_name: N) -> Result<(), PyErr> where
    N: ToPyObject, 

Deletes an attribute.

This is equivalent to the Python expression del self.attr_name.

pub fn compare<O>(&self, other: O) -> Result<Ordering, PyErr> where
    O: ToPyObject, 

Compares two Python objects.

This is equivalent to:

if self == other:
    return Equal
elif a < b:
    return Less
elif a > b:
    return Greater
else:
    raise TypeError("PyAny::compare(): All comparisons returned false")

pub fn rich_compare<O>(
    &self,
    other: O,
    compare_op: CompareOp
) -> Result<&PyAny, PyErr> where
    O: ToPyObject, 

Compares two Python objects.

Depending on the value of compare_op, this is equivalent to one of the following Python expressions:

• CompareOp::Eq: self == other
• CompareOp::Ne: self != other
• CompareOp::Lt: self < other
• CompareOp::Le: self <= other
• CompareOp::Gt: self > other
• CompareOp::Ge: self >= other

pub fn is_callable(&self) -> bool

Determines whether this object is callable.

pub fn call(
    &self,
    args: impl IntoPy<Py<PyTuple>>,
    kwargs: Option<&PyDict>
) -> Result<&PyAny, PyErr>

Calls the object.

This is equivalent to the Python expression self(*args, **kwargs).

pub fn call0(&self) -> Result<&PyAny, PyErr>

Calls the object without arguments.

This is equivalent to the Python expression self().

pub fn call1(&self, args: impl IntoPy<Py<PyTuple>>) -> Result<&PyAny, PyErr>

Calls the object with only positional arguments.

This is equivalent to the Python expression self(*args).

pub fn call_method(
    &self,
    name: &str,
    args: impl IntoPy<Py<PyTuple>>,
    kwargs: Option<&PyDict>
) -> Result<&PyAny, PyErr>

Calls a method on the object.

This is equivalent to the Python expression self.name(*args, **kwargs).

Example

use pyo3::types::IntoPyDict;

let gil = Python::acquire_gil();
let py = gil.python();
let list = vec![3, 6, 5, 4, 7].to_object(py);
let dict = vec![("reverse", true)].into_py_dict(py);
list.call_method(py, "sort", (), Some(dict)).unwrap();
assert_eq!(list.extract::<Vec<i32>>(py).unwrap(), vec![7, 6, 5, 4, 3]);

let new_element = 1.to_object(py);
list.call_method(py, "append", (new_element,), None).unwrap();
assert_eq!(list.extract::<Vec<i32>>(py).unwrap(), vec![7, 6, 5, 4, 3, 1]);

pub fn call_method0(&self, name: &str) -> Result<&PyAny, PyErr>

Calls a method on the object without arguments.

This is equivalent to the Python expression self.name().

pub fn call_method1(
    &self,
    name: &str,
    args: impl IntoPy<Py<PyTuple>>
) -> Result<&PyAny, PyErr>

Calls a method on the object with only positional arguments.

This is equivalent to the Python expression self.name(*args).

pub fn is_true(&self) -> Result<bool, PyErr>

Returns whether the object is considered to be true.

This is equivalent to the Python expression bool(self).

pub fn is_none(&self) -> bool

Returns whether the object is considered to be None.

This is equivalent to the Python expression self is None.

pub fn is_empty(&self) -> Result<bool, PyErr>

Returns true if the sequence or mapping has a length of 0.

This is equivalent to the Python expression len(self) == 0.

pub fn get_item<K>(&self, key: K) -> Result<&PyAny, PyErr> where
    K: ToBorrowedObject, 

Gets an item from the collection.

This is equivalent to the Python expression self[key].

pub fn set_item<K, V>(&self, key: K, value: V) -> Result<(), PyErr> where
    K: ToBorrowedObject,
    V: ToBorrowedObject, 

Sets a collection item value.

This is equivalent to the Python expression self[key] = value.

pub fn del_item<K>(&self, key: K) -> Result<(), PyErr> where
    K: ToBorrowedObject, 

Deletes an item from the collection.

This is equivalent to the Python expression del self[key].

pub fn iter(&self) -> Result<&PyIterator, PyErr>

Takes an object and returns an iterator for it.

This is typically a new iterator but if the argument is an iterator, this returns itself.

pub fn get_type(&self) -> &PyType

Returns the Python type object for this object’s type.

pub fn get_type_ptr(&self) -> *mut PyTypeObject

Returns the Python type pointer for this object.

pub fn cast_as<'a, D>(&'a self) -> Result<&'a D, PyDowncastError<'a>> where
    D: PyTryFrom<'a>, 

Casts the PyObject to a concrete Python object type.

This can cast only to native Python types, not types implemented in Rust.

pub fn extract<'a, D>(&'a self) -> Result<D, PyErr> where
    D: FromPyObject<'a>, 

Extracts some type from the Python object.

This is a wrapper function around FromPyObject::extract().

pub fn get_refcnt(&self) -> isize

Returns the reference count for the Python object.

pub fn repr(&self) -> Result<&PyString, PyErr>

Computes the “repr” representation of self.

This is equivalent to the Python expression repr(self).

pub fn str(&self) -> Result<&PyString, PyErr>

Computes the “str” representation of self.

This is equivalent to the Python expression str(self).

pub fn hash(&self) -> Result<isize, PyErr>

Retrieves the hash code of self.

This is equivalent to the Python expression hash(self).

pub fn len(&self) -> Result<usize, PyErr>

Returns the length of the sequence or mapping.

This is equivalent to the Python expression len(self).

pub fn dir(&self) -> &PyList

Returns the list of attributes of this object.

This is equivalent to the Python expression dir(self).

pub fn is_instance<T>(&self) -> Result<bool, PyErr> where
    T: PyTypeObject, 

Checks whether this object is an instance of type T.

This is equivalent to the Python expression isinstance(self, T).

Trait Implementations

impl AsPyPointer for PyArrayDescr

fn as_ptr(&self) -> *mut PyObject

Gets the underlying FFI pointer, returns a borrowed pointer.

impl AsRef<PyAny> for PyArrayDescr

fn as_ref(&self) -> &PyAny

Performs the conversion.

impl Debug for PyArrayDescr

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

Formats the value using the given formatter.

impl Deref for PyArrayDescr

type Target = PyAny

The resulting type after dereferencing.

fn deref(&self) -> &PyAny

Dereferences the value.

impl Display for PyArrayDescr

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

Formats the value using the given formatter.

impl<'a> From<&'a PyArrayDescr> for &'a PyAny

fn from(ob: &'a PyArrayDescr) -> Self

Performs the conversion.

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

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

Extracts Self from the source PyObject.

impl IntoPy<Py<PyArrayDescr>> for &PyArrayDescr

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

Performs the conversion.

impl PartialEq<PyArrayDescr> for PyArrayDescr

fn eq(&self, o: &PyArrayDescr) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]

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

This method tests for !=.

impl PyLayout<PyArrayDescr> for PyArray_Descr

const IS_NATIVE_TYPE: bool

fn get_super(&mut self) -> Option<&mut <T as PyTypeInfo>::BaseLayout>

fn py_init(&mut self, _value: T)

unsafe fn py_drop(&mut self, _py: Python<'_>)

impl PyNativeType for PyArrayDescr

fn py(&self) -> Python<'_>

unsafe fn unchecked_downcast(obj: &PyAny) -> &Self

Cast &PyAny to &Self without no type checking.

impl PyTypeInfo for PyArrayDescr

type Type = ()

Type of objects to store in PyObject struct

type BaseType = PyAny

Base class

type Layout = PyArray_Descr

Layout

type BaseLayout = PyObject

Layout of Basetype.

type Initializer = PyNativeTypeInitializer<Self>

Initializer for layout

type AsRefTarget = Self

Utility type to make Py::as_ref work

const NAME: &'static str

Class name

const MODULE: Option<&'static str>

Module name, if any

fn type_object_raw(_py: Python<'_>) -> *mut PyTypeObject

PyTypeObject instance for this type.

fn is_type_of(ptr: &PyAny) -> bool

Checks if object is an instance of this type or a subclass of this type.

const DESCRIPTION: &'static str

Class doc string

const FLAGS: usize

Type flags (ie PY_TYPE_FLAG_GC, PY_TYPE_FLAG_WEAKREF)

fn is_exact_type_of(object: &PyAny) -> bool

Checks if object is an instance of this type.

impl ToPyObject for PyArrayDescr

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

Converts self into a Python object.