Enum IterNextOutput

pub enum IterNextOutput<T, U> {
    Yield(T),
    Return(U),
}

👎Deprecated since 0.21.0: Use Option or PyStopIteration instead.

Output of __next__ which can either yield the next value in the iteration, or return a value to raise StopIteration in Python.

Usage example:

use pyo3::prelude::*;
use pyo3::iter::IterNextOutput;

#[pyclass]
struct PyClassIter {
    count: usize,
}

#[pymethods]
impl PyClassIter {
    #[new]
    pub fn new() -> Self {
        PyClassIter { count: 0 }
    }

    fn __next__(&mut self) -> IterNextOutput<usize, &'static str> {
        if self.count < 5 {
            self.count += 1;
            // Given an instance `counter`, First five `next(counter)` calls yield 1, 2, 3, 4, 5.
            IterNextOutput::Yield(self.count)
        } else {
            // At the sixth time, we get a `StopIteration` with `'Ended'`.
            //     try:
            //         next(counter)
            //     except StopIteration as e:
            //         assert e.value == 'Ended'
            IterNextOutput::Return("Ended")
        }
    }
}

Variants

Yield(T)

👎Deprecated since 0.21.0: Use Option or PyStopIteration instead.

The value yielded by the iterator.

Return(U)

👎Deprecated since 0.21.0: Use Option or PyStopIteration instead.

The StopIteration object.