Struct numpy::borrow::PyReadwriteArray

pub struct PyReadwriteArray<'py, T, D>where
    T: Element,
    D: Dimension,{ /* private fields */ }

Read-write borrow of an array.

An instance of this type ensures that there are no instances of PyReadonlyArray and no other instances of PyReadwriteArray, i.e. that only a single exclusive reference into the interior of the array can be created safely.

See the module-level documentation for more.

Implementations

impl<'py, T, D> PyReadwriteArray<'py, T, D>where T: Element, D: Dimension,

pub fn as_array_mut(&mut self) -> ArrayViewMut<'_, T, D>

Provides a mutable array view of the interior of the NumPy array.

pub fn as_slice_mut(&mut self) -> Result<&mut [T], NotContiguousError>

Provide a mutable slice view of the interior of the NumPy array if it is contiguous.

pub fn get_mut<I>(&mut self, index: I) -> Option<&mut T>where I: NpyIndex<Dim = D>,

Provide a mutable reference to an element of the NumPy array if the index is within bounds.

impl<'py, N, D> PyReadwriteArray<'py, N, D>where N: Scalar + Element, D: Dimension,

pub fn try_as_matrix_mut<R, C, RStride, CStride>( &self ) -> Option<MatrixViewMut<'_, N, R, C, RStride, CStride>>where R: Dim, C: Dim, RStride: Dim, CStride: Dim,

Try to convert this array into a nalgebra::MatrixViewMut using the given shape and strides.

impl<'py, N> PyReadwriteArray<'py, N, Ix1>where N: Scalar + Element,

pub fn as_matrix_mut(&self) -> DMatrixViewMut<'_, N, Dyn, Dyn>

Convert this one-dimensional array into a nalgebra::DMatrixViewMut using dynamic strides.

Panics

Panics if the array has negative strides.

impl<'py, N> PyReadwriteArray<'py, N, Ix2>where N: Scalar + Element,

pub fn as_matrix_mut(&self) -> DMatrixViewMut<'_, N, Dyn, Dyn>

Convert this two-dimensional array into a nalgebra::DMatrixViewMut using dynamic strides.

Panics

Panics if the array has negative strides.

impl<'py, T> PyReadwriteArray<'py, T, Ix1>where T: Element,

pub fn resize<ID: IntoDimension>(self, dims: ID) -> PyResult<Self>

Extends or truncates the dimensions of an array.

Safe wrapper for PyArray::resize.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray = PyArray::arange(py, 0, 10, 1);
    assert_eq!(pyarray.len(), 10);

    let pyarray = pyarray.readwrite();
    let pyarray = pyarray.resize(100).unwrap();
    assert_eq!(pyarray.len(), 100);
});

Methods from Deref<Target = PyReadonlyArray<'py, T, D>>

pub fn as_array(&self) -> ArrayView<'_, T, D>

Provides an immutable array view of the interior of the NumPy array.

pub fn as_slice(&self) -> Result<&[T], NotContiguousError>

Provide an immutable slice view of the interior of the NumPy array if it is contiguous.

pub fn get<I>(&self, index: I) -> Option<&T>where I: NpyIndex<Dim = D>,

Provide an immutable reference to an element of the NumPy array if the index is within bounds.

pub fn try_as_matrix<R, C, RStride, CStride>( &self ) -> Option<MatrixView<'_, N, R, C, RStride, CStride>>where R: Dim, C: Dim, RStride: Dim, CStride: Dim,

Try to convert this array into a nalgebra::MatrixView using the given shape and strides.

pub fn as_matrix(&self) -> DMatrixView<'_, N, Dyn, Dyn>

Convert this one-dimensional array into a nalgebra::DMatrixView using dynamic strides.

Panics

Panics if the array has negative strides.

pub fn as_matrix(&self) -> DMatrixView<'_, N, Dyn, Dyn>

Convert this two-dimensional array into a nalgebra::DMatrixView using dynamic strides.

Panics

Panics if the array has negative strides.

Methods from Deref<Target = PyArray<T, D>>

pub fn as_untyped(&self) -> &PyUntypedArray

Access an untyped representation of this array.

pub fn to_owned(&self) -> Py<Self>

Turn &PyArray<T,D> into Py<PyArray<T,D>>, i.e. a pointer into Python’s heap which is independent of the GIL lifetime.

This method can be used to avoid lifetime annotations of function arguments or return values.

Example

use numpy::PyArray1;
use pyo3::{Py, Python};

let array: Py<PyArray1<f64>> = Python::with_gil(|py| {
    PyArray1::zeros(py, 5, false).to_owned()
});

Python::with_gil(|py| {
    assert_eq!(array.as_ref(py).readonly().as_slice().unwrap(), [0.0; 5]);
});

pub fn data(&self) -> *mut T

Returns a pointer to the first element of the array.

pub fn dims(&self) -> D

Same as shape, but returns D instead of &[usize].

pub unsafe fn as_slice(&self) -> Result<&[T], NotContiguousError>

Returns an immutable view of the internal data as a slice.

Safety

Calling this method is undefined behaviour if the underlying array is aliased mutably by other instances of PyArray or concurrently modified by Python or other native code.

Please consider the safe alternative PyReadonlyArray::as_slice.

pub unsafe fn as_slice_mut(&self) -> Result<&mut [T], NotContiguousError>

Returns a mutable view of the internal data as a slice.

Safety

Calling this method is undefined behaviour if the underlying array is aliased immutably or mutably by other instances of PyArray or concurrently modified by Python or other native code.

Please consider the safe alternative PyReadwriteArray::as_slice_mut.

pub unsafe fn get(&self, index: impl NpyIndex<Dim = D>) -> Option<&T>

Get a reference of the specified element if the given index is valid.

Safety

Calling this method is undefined behaviour if the underlying array is aliased mutably by other instances of PyArray or concurrently modified by Python or other native code.

Consider using safe alternatives like PyReadonlyArray::get.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray = PyArray::arange(py, 0, 16, 1).reshape([2, 2, 4]).unwrap();

    assert_eq!(unsafe { *pyarray.get([1, 0, 3]).unwrap() }, 11);
});

pub unsafe fn get_mut(&self, index: impl NpyIndex<Dim = D>) -> Option<&mut T>

Same as get, but returns Option<&mut T>.

Safety

Calling this method is undefined behaviour if the underlying array is aliased immutably or mutably by other instances of PyArray or concurrently modified by Python or other native code.

Consider using safe alternatives like PyReadwriteArray::get_mut.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray = PyArray::arange(py, 0, 16, 1).reshape([2, 2, 4]).unwrap();

    unsafe {
        *pyarray.get_mut([1, 0, 3]).unwrap() = 42;
    }

    assert_eq!(unsafe { *pyarray.get([1, 0, 3]).unwrap() }, 42);
});

pub unsafe fn uget<Idx>(&self, index: Idx) -> &Twhere Idx: NpyIndex<Dim = D>,

Get an immutable reference of the specified element, without checking the given index.

See NpyIndex for what types can be used as the index.

Safety

Passing an invalid index is undefined behavior. The element must also have been initialized and all other references to it is must also be shared.

See PyReadonlyArray::get for a safe alternative.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray = PyArray::arange(py, 0, 16, 1).reshape([2, 2, 4]).unwrap();

    assert_eq!(unsafe { *pyarray.uget([1, 0, 3]) }, 11);
});

pub unsafe fn uget_mut<Idx>(&self, index: Idx) -> &mut Twhere Idx: NpyIndex<Dim = D>,

Same as uget, but returns &mut T.

Safety

Passing an invalid index is undefined behavior. The element must also have been initialized and other references to it must not exist.

See PyReadwriteArray::get_mut for a safe alternative.

pub unsafe fn uget_raw<Idx>(&self, index: Idx) -> *mut Twhere Idx: NpyIndex<Dim = D>,

Same as uget, but returns *mut T.

Safety

Passing an invalid index is undefined behavior.

pub fn get_owned<Idx>(&self, index: Idx) -> Option<T>where Idx: NpyIndex<Dim = D>,

Get a copy of the specified element in the array.

See NpyIndex for what types can be used as the index.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray = PyArray::arange(py, 0, 16, 1).reshape([2, 2, 4]).unwrap();

    assert_eq!(pyarray.get_owned([1, 0, 3]), Some(11));
});

pub fn to_dyn(&self) -> &PyArray<T, IxDyn>

Turn an array with fixed dimensionality into one with dynamic dimensionality.

pub fn to_vec(&self) -> Result<Vec<T>, NotContiguousError>

Returns a copy of the internal data of the array as a Vec.

Fails if the internal array is not contiguous. See also as_slice.

Example

use numpy::PyArray2;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray= py
        .eval("__import__('numpy').array([[0, 1], [2, 3]], dtype='int64')", None, None)
        .unwrap()
        .downcast::<PyArray2<i64>>()
        .unwrap();

    assert_eq!(pyarray.to_vec().unwrap(), vec![0, 1, 2, 3]);
});

pub fn try_readonly(&self) -> Result<PyReadonlyArray<'_, T, D>, BorrowError>

Get an immutable borrow of the NumPy array

pub fn readonly(&self) -> PyReadonlyArray<'_, T, D>

Get an immutable borrow of the NumPy array

Panics

Panics if the allocation backing the array is currently mutably borrowed.

For a non-panicking variant, use try_readonly.

pub fn try_readwrite(&self) -> Result<PyReadwriteArray<'_, T, D>, BorrowError>

Get a mutable borrow of the NumPy array

pub fn readwrite(&self) -> PyReadwriteArray<'_, T, D>

Get a mutable borrow of the NumPy array

Panics

Panics if the allocation backing the array is currently borrowed or if the array is flagged as not writeable.

For a non-panicking variant, use try_readwrite.

pub unsafe fn as_array(&self) -> ArrayView<'_, T, D>

Returns an ArrayView of the internal array.

See also PyReadonlyArray::as_array.

Safety

Calling this method invalidates all exclusive references to the internal data, e.g. &mut [T] or ArrayViewMut.

pub unsafe fn as_array_mut(&self) -> ArrayViewMut<'_, T, D>

Returns an ArrayViewMut of the internal array.

See also PyReadwriteArray::as_array_mut.

Safety

Calling this method invalidates all other references to the internal data, e.g. ArrayView or ArrayViewMut.

pub fn as_raw_array(&self) -> RawArrayView<T, D>

Returns the internal array as RawArrayView enabling element access via raw pointers

pub fn as_raw_array_mut(&self) -> RawArrayViewMut<T, D>

Returns the internal array as RawArrayViewMut enabling element access via raw pointers

pub fn to_owned_array(&self) -> Array<T, D>

Get a copy of the array as an ndarray::Array.

Example

use numpy::PyArray;
use ndarray::array;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray = PyArray::arange(py, 0, 4, 1).reshape([2, 2]).unwrap();

    assert_eq!(
        pyarray.to_owned_array(),
        array![[0, 1], [2, 3]]
    )
});

pub unsafe fn try_as_matrix<R, C, RStride, CStride>( &self ) -> Option<MatrixView<'_, N, R, C, RStride, CStride>>where R: Dim, C: Dim, RStride: Dim, CStride: Dim,

Try to convert this array into a nalgebra::MatrixView using the given shape and strides.

Safety

Calling this method invalidates all exclusive references to the internal data, e.g. ArrayViewMut or MatrixSliceMut.

pub unsafe fn try_as_matrix_mut<R, C, RStride, CStride>( &self ) -> Option<MatrixViewMut<'_, N, R, C, RStride, CStride>>where R: Dim, C: Dim, RStride: Dim, CStride: Dim,

Try to convert this array into a nalgebra::MatrixViewMut using the given shape and strides.

Safety

Calling this method invalidates all other references to the internal data, e.g. ArrayView, MatrixSlice, ArrayViewMut or MatrixSliceMut.

pub fn item(&self) -> T

Get the single element of a zero-dimensional array.

See inner for an example.

pub fn copy_to<U: Element>(&self, other: &PyArray<U, D>) -> PyResult<()>

Copies self into other, performing a data type conversion if necessary.

See also PyArray_CopyInto.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray_f = PyArray::arange(py, 2.0, 5.0, 1.0);
    let pyarray_i = unsafe { PyArray::<i64, _>::new(py, [3], false) };

    assert!(pyarray_f.copy_to(pyarray_i).is_ok());

    assert_eq!(pyarray_i.readonly().as_slice().unwrap(), &[2, 3, 4]);
});

pub fn cast<'py, U: Element>( &'py self, is_fortran: bool ) -> PyResult<&'py PyArray<U, D>>

Cast the PyArray<T> to PyArray<U>, by allocating a new array.

See also PyArray_CastToType.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray_f = PyArray::arange(py, 2.0, 5.0, 1.0);

    let pyarray_i = pyarray_f.cast::<i32>(false).unwrap();

    assert_eq!(pyarray_i.readonly().as_slice().unwrap(), &[2, 3, 4]);
});

pub fn reshape_with_order<'py, ID: IntoDimension>( &'py self, dims: ID, order: NPY_ORDER ) -> PyResult<&'py PyArray<T, ID::Dim>>

Construct a new array which has same values as self, but has different dimensions specified by dims and a possibly different memory order specified by order.

See also numpy.reshape and PyArray_Newshape.

Example

use numpy::{npyffi::NPY_ORDER, PyArray};
use pyo3::Python;
use ndarray::array;

Python::with_gil(|py| {
    let array =
        PyArray::from_iter(py, 0..9).reshape_with_order([3, 3], NPY_ORDER::NPY_FORTRANORDER).unwrap();

    assert_eq!(array.readonly().as_array(), array![[0, 3, 6], [1, 4, 7], [2, 5, 8]]);
    assert!(array.is_fortran_contiguous());

    assert!(array.reshape([5]).is_err());
});

pub fn reshape<'py, ID: IntoDimension>( &'py self, dims: ID ) -> PyResult<&'py PyArray<T, ID::Dim>>

Special case of reshape_with_order which keeps the memory order the same.

pub unsafe fn resize<ID: IntoDimension>(&self, dims: ID) -> PyResult<()>

Extends or truncates the dimensions of an array.

This method works only on contiguous arrays. Missing elements will be initialized as if calling zeros.

See also ndarray.resize and PyArray_Resize.

Safety

There should be no outstanding references (shared or exclusive) into the array as this method might re-allocate it and thereby invalidate all pointers into it.

Example

use numpy::PyArray;
use pyo3::Python;

Python::with_gil(|py| {
    let pyarray = PyArray::<f64, _>::zeros(py, (10, 10), false);
    assert_eq!(pyarray.shape(), [10, 10]);

    unsafe {
        pyarray.resize((100, 100)).unwrap();
    }
    assert_eq!(pyarray.shape(), [100, 100]);
});

Methods from Deref<Target = PyUntypedArray>

pub fn as_array_ptr(&self) -> *mut PyArrayObject

Returns a raw pointer to the underlying PyArrayObject.

pub fn dtype(&self) -> &PyArrayDescr

Returns the dtype of the array.

See also ndarray.dtype and PyArray_DTYPE.

Example

use numpy::{dtype, PyArray};
use pyo3::Python;

Python::with_gil(|py| {
   let array = PyArray::from_vec(py, vec![1_i32, 2, 3]);

   assert!(array.dtype().is_equiv_to(dtype::<i32>(py)));
});

pub fn is_contiguous(&self) -> bool

Returns true if the internal data of the array is contiguous, indepedently of whether C-style/row-major or Fortran-style/column-major.

Example

use numpy::PyArray1;
use pyo3::{types::IntoPyDict, Python};

Python::with_gil(|py| {
    let array = PyArray1::arange(py, 0, 10, 1);
    assert!(array.is_contiguous());

    let view = py
        .eval("array[::2]", None, Some([("array", array)].into_py_dict(py)))
        .unwrap()
        .downcast::<PyArray1<i32>>()
        .unwrap();
    assert!(!view.is_contiguous());
});

pub fn is_fortran_contiguous(&self) -> bool

Returns true if the internal data of the array is Fortran-style/column-major contiguous.

pub fn is_c_contiguous(&self) -> bool

Returns true if the internal data of the array is C-style/row-major contiguous.

pub fn ndim(&self) -> usize

Returns the number of dimensions of the array.

See also ndarray.ndim and PyArray_NDIM.

Example

use numpy::PyArray3;
use pyo3::Python;

Python::with_gil(|py| {
    let arr = PyArray3::<f64>::zeros(py, [4, 5, 6], false);

    assert_eq!(arr.ndim(), 3);
});

pub fn strides(&self) -> &[isize]

Returns a slice indicating how many bytes to advance when iterating along each axis.

See also ndarray.strides and PyArray_STRIDES.

Example

use numpy::PyArray3;
use pyo3::Python;

Python::with_gil(|py| {
    let arr = PyArray3::<f64>::zeros(py, [4, 5, 6], false);

    assert_eq!(arr.strides(), &[240, 48, 8]);
});

pub fn shape(&self) -> &[usize]

Returns a slice which contains dimmensions of the array.

See also [ndarray.shape][ndaray-shape] and PyArray_DIMS.

Example

use numpy::PyArray3;
use pyo3::Python;

Python::with_gil(|py| {
    let arr = PyArray3::<f64>::zeros(py, [4, 5, 6], false);

    assert_eq!(arr.shape(), &[4, 5, 6]);
});

pub fn len(&self) -> usize

Calculates the total number of elements in the array.

pub fn is_empty(&self) -> bool

Returns true if the there are no elements in the array.

Methods from Deref<Target = PyAny>

pub fn is<T>(&self, other: &T) -> boolwhere T: AsPyPointer,

Returns whether self and other point to the same object. To compare the equality of two objects (the == operator), use eq.

This is equivalent to the Python expression self is other.

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

Determines whether this object has the given attribute.

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

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern attr_name.

Example: intern!ing the attribute name

#[pyfunction]
fn has_version(sys: &PyModule) -> PyResult<bool> {
    sys.hasattr(intern!(sys.py(), "version"))
}

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

Retrieves an attribute value.

This is equivalent to the Python expression self.attr_name.

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern attr_name.

Example: intern!ing the attribute name

#[pyfunction]
fn version(sys: &PyModule) -> PyResult<&PyAny> {
    sys.getattr(intern!(sys.py(), "version"))
}

pub fn setattr<N, V>(&self, attr_name: N, value: V) -> Result<(), PyErr>where N: IntoPy<Py<PyString>>, V: ToPyObject,

Sets an attribute value.

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

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Example: intern!ing the attribute name

#[pyfunction]
fn set_answer(ob: &PyAny) -> PyResult<()> {
    ob.setattr(intern!(ob.py(), "answer"), 42)
}

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

Deletes an attribute.

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

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern attr_name.

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

Returns an Ordering between self and other.

This is equivalent to the following Python code:

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

Examples

use pyo3::prelude::*;
use pyo3::types::PyFloat;
use std::cmp::Ordering;

Python::with_gil(|py| -> PyResult<()> {
    let a = PyFloat::new(py, 0_f64);
    let b = PyFloat::new(py, 42_f64);
    assert_eq!(a.compare(b)?, Ordering::Less);
    Ok(())
})?;

It will return PyErr for values that cannot be compared:

use pyo3::prelude::*;
use pyo3::types::{PyFloat, PyString};

Python::with_gil(|py| -> PyResult<()> {
    let a = PyFloat::new(py, 0_f64);
    let b = PyString::new(py, "zero");
    assert!(a.compare(b).is_err());
    Ok(())
})?;

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

Tests whether two Python objects obey a given CompareOp.

lt, le, eq, ne, gt and ge are the specialized versions of this function.

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

compare_op	Python expression
CompareOp::Eq	self == other
CompareOp::Ne	self != other
CompareOp::Lt	self < other
CompareOp::Le	self <= other
CompareOp::Gt	self > other
CompareOp::Ge	self >= other

Examples

use pyo3::class::basic::CompareOp;
use pyo3::prelude::*;
use pyo3::types::PyInt;

Python::with_gil(|py| -> PyResult<()> {
    let a: &PyInt = 0_u8.into_py(py).into_ref(py).downcast()?;
    let b: &PyInt = 42_u8.into_py(py).into_ref(py).downcast()?;
    assert!(a.rich_compare(b, CompareOp::Le)?.is_true()?);
    Ok(())
})?;

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

Tests whether this object is less than another.

This is equivalent to the Python expression self < other.

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

Tests whether this object is less than or equal to another.

This is equivalent to the Python expression self <= other.

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

Tests whether this object is equal to another.

This is equivalent to the Python expression self == other.

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

Tests whether this object is not equal to another.

This is equivalent to the Python expression self != other.

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

Tests whether this object is greater than another.

This is equivalent to the Python expression self > other.

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

Tests whether this object is greater than or equal to another.

This is equivalent to the Python expression self >= other.

pub fn is_callable(&self) -> bool

Determines whether this object appears callable.

This is equivalent to Python’s callable() function.

Examples

use pyo3::prelude::*;

Python::with_gil(|py| -> PyResult<()> {
    let builtins = PyModule::import(py, "builtins")?;
    let print = builtins.getattr("print")?;
    assert!(print.is_callable());
    Ok(())
})?;

This is equivalent to the Python statement assert callable(print).

Note that unless an API needs to distinguish between callable and non-callable objects, there is no point in checking for callability. Instead, it is better to just do the call and handle potential exceptions.

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).

Examples

use pyo3::prelude::*;
use pyo3::types::PyDict;

const CODE: &str = r#"
def function(*args, **kwargs):
    assert args == ("hello",)
    assert kwargs == {"cruel": "world"}
    return "called with args and kwargs"
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let fun = module.getattr("function")?;
    let args = ("hello",);
    let kwargs = PyDict::new(py);
    kwargs.set_item("cruel", "world")?;
    let result = fun.call(args, Some(kwargs))?;
    assert_eq!(result.extract::<&str>()?, "called with args and kwargs");
    Ok(())
})

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

Calls the object without arguments.

This is equivalent to the Python expression self().

Examples

use pyo3::prelude::*;

Python::with_gil(|py| -> PyResult<()> {
    let module = PyModule::import(py, "builtins")?;
    let help = module.getattr("help")?;
    help.call0()?;
    Ok(())
})?;

This is equivalent to the Python expression help().

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).

Examples

use pyo3::prelude::*;

const CODE: &str = r#"
def function(*args, **kwargs):
    assert args == ("hello",)
    assert kwargs == {}
    return "called with args"
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let fun = module.getattr("function")?;
    let args = ("hello",);
    let result = fun.call1(args)?;
    assert_eq!(result.extract::<&str>()?, "called with args");
    Ok(())
})

pub fn call_method<N, A>( &self, name: N, args: A, kwargs: Option<&PyDict> ) -> Result<&PyAny, PyErr>where N: IntoPy<Py<PyString>>, A: IntoPy<Py<PyTuple>>,

Calls a method on the object.

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

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Examples

use pyo3::prelude::*;
use pyo3::types::PyDict;

const CODE: &str = r#"
class A:
    def method(self, *args, **kwargs):
        assert args == ("hello",)
        assert kwargs == {"cruel": "world"}
        return "called with args and kwargs"
a = A()
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let instance = module.getattr("a")?;
    let args = ("hello",);
    let kwargs = PyDict::new(py);
    kwargs.set_item("cruel", "world")?;
    let result = instance.call_method("method", args, Some(kwargs))?;
    assert_eq!(result.extract::<&str>()?, "called with args and kwargs");
    Ok(())
})

pub fn call_method0<N>(&self, name: N) -> Result<&PyAny, PyErr>where N: IntoPy<Py<PyString>>,

Calls a method on the object without arguments.

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

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Examples

use pyo3::prelude::*;

const CODE: &str = r#"
class A:
    def method(self, *args, **kwargs):
        assert args == ()
        assert kwargs == {}
        return "called with no arguments"
a = A()
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let instance = module.getattr("a")?;
    let result = instance.call_method0("method")?;
    assert_eq!(result.extract::<&str>()?, "called with no arguments");
    Ok(())
})

pub fn call_method1<N, A>(&self, name: N, args: A) -> Result<&PyAny, PyErr>where N: IntoPy<Py<PyString>>, A: IntoPy<Py<PyTuple>>,

Calls a method on the object with only positional arguments.

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

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Examples

use pyo3::prelude::*;

const CODE: &str = r#"
class A:
    def method(self, *args, **kwargs):
        assert args == ("hello",)
        assert kwargs == {}
        return "called with args"
a = A()
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let instance = module.getattr("a")?;
    let args = ("hello",);
    let result = instance.call_method1("method", args)?;
    assert_eq!(result.extract::<&str>()?, "called with args");
    Ok(())
})

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_ellipsis(&self) -> bool

Returns whether the object is Ellipsis, e.g. ....

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

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: ToPyObject,

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: ToPyObject, V: ToPyObject,

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: ToPyObject,

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 downcast<'p, T>(&'p self) -> Result<&'p T, PyDowncastError<'p>>where T: PyTryFrom<'p>,

Downcast this PyAny to a concrete Python type or pyclass.

Note that you can often avoid downcasting yourself by just specifying the desired type in function or method signatures. However, manual downcasting is sometimes necessary.

For extracting a Rust-only type, see PyAny::extract.

Example: Downcasting to a specific Python object

use pyo3::prelude::*;
use pyo3::types::{PyDict, PyList};

Python::with_gil(|py| {
    let dict = PyDict::new(py);
    assert!(dict.is_instance_of::<PyAny>());
    let any: &PyAny = dict.as_ref();

    assert!(any.downcast::<PyDict>().is_ok());
    assert!(any.downcast::<PyList>().is_err());
});

Example: Getting a reference to a pyclass

This is useful if you want to mutate a PyObject that might actually be a pyclass.

use pyo3::prelude::*;

#[pyclass]
struct Class {
    i: i32,
}

Python::with_gil(|py| {
    let class: &PyAny = Py::new(py, Class { i: 0 }).unwrap().into_ref(py);

    let class_cell: &PyCell<Class> = class.downcast()?;

    class_cell.borrow_mut().i += 1;

    // Alternatively you can get a `PyRefMut` directly
    let class_ref: PyRefMut<'_, Class> = class.extract()?;
    assert_eq!(class_ref.i, 1);
    Ok(())
})

pub fn downcast_exact<'p, T>(&'p self) -> Result<&'p T, PyDowncastError<'p>>where T: PyTryFrom<'p>,

Downcast this PyAny to a concrete Python type or pyclass (but not a subclass of it).

It is almost always better to use PyAny::downcast because it accounts for Python subtyping. Use this method only when you do not want to allow subtypes.

The advantage of this method over PyAny::downcast is that it is faster. The implementation of downcast_exact uses the equivalent of the Python expression type(self) is T, whereas downcast uses isinstance(self, T).

For extracting a Rust-only type, see PyAny::extract.

Example: Downcasting to a specific Python object but not a subtype

use pyo3::prelude::*;
use pyo3::types::{PyBool, PyLong};

Python::with_gil(|py| {
    let b = PyBool::new(py, true);
    assert!(b.is_instance_of::<PyBool>());
    let any: &PyAny = b.as_ref();

    // `bool` is a subtype of `int`, so `downcast` will accept a `bool` as an `int`
    // but `downcast_exact` will not.
    assert!(any.downcast::<PyLong>().is_ok());
    assert!(any.downcast_exact::<PyLong>().is_err());

    assert!(any.downcast_exact::<PyBool>().is_ok());
});

pub unsafe fn downcast_unchecked<'p, T>(&'p self) -> &'p Twhere T: PyTryFrom<'p>,

Converts this PyAny to a concrete Python type without checking validity.

Safety

Callers must ensure that the type is valid or risk type confusion.

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(&self, ty: &PyAny) -> Result<bool, PyErr>

Checks whether this object is an instance of type ty.

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

pub fn is_exact_instance(&self, ty: &PyAny) -> bool

Checks whether this object is an instance of exactly type ty (not a subclass).

This is equivalent to the Python expression type(self) is ty.

pub fn is_instance_of<T>(&self) -> boolwhere T: PyTypeInfo,

Checks whether this object is an instance of type T.

This is equivalent to the Python expression isinstance(self, T), if the type T is known at compile time.

pub fn is_exact_instance_of<T>(&self) -> boolwhere T: PyTypeInfo,

Checks whether this object is an instance of exactly type T.

This is equivalent to the Python expression type(self) is T, if the type T is known at compile time.

pub fn contains<V>(&self, value: V) -> Result<bool, PyErr>where V: ToPyObject,

Determines if self contains value.

This is equivalent to the Python expression value in self.

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

Returns a GIL marker constrained to the lifetime of this type.

pub fn as_ptr(&self) -> *mut PyObject

Returns the raw FFI pointer represented by self.

Safety

Callers are responsible for ensuring that the pointer does not outlive self.

The reference is borrowed; callers should not decrease the reference count when they are finished with the pointer.

pub fn into_ptr(&self) -> *mut PyObject

Returns an owned raw FFI pointer represented by self.

Safety

The reference is owned; when finished the caller should either transfer ownership of the pointer or decrease the reference count (e.g. with pyo3::ffi::Py_DecRef).

pub fn py_super(&self) -> Result<&PySuper, PyErr>

Return a proxy object that delegates method calls to a parent or sibling class of type.

This is equivalent to the Python expression super()

Trait Implementations

impl<'py, T, D> Debug for PyReadwriteArray<'py, T, D>where T: Element, D: Dimension,

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

Formats the value using the given formatter.

impl<'py, T, D> Deref for PyReadwriteArray<'py, T, D>where T: Element, D: Dimension,

type Target = PyReadonlyArray<'py, T, D>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'a, T, D> Drop for PyReadwriteArray<'a, T, D>where T: Element, D: Dimension,

fn drop(&mut self)

Executes the destructor for this type.

impl<'py, T: Element, D: Dimension> FromPyObject<'py> for PyReadwriteArray<'py, T, D>

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

Extracts Self from the source PyObject.