fix: don’t panic in when extracting PyReadwriteArray

src/borrow/mod.rs

@@ -175,7 +175,7 @@ use std::ops::Deref;
 use ndarray::{
     ArrayView, ArrayViewMut, Dimension, IntoDimension, Ix0, Ix1, Ix2, Ix3, Ix4, Ix5, Ix6, IxDyn,
 };
-use pyo3::{Borrowed, Bound, CastError, FromPyObject, PyAny, PyResult};
+use pyo3::{Borrowed, Bound, FromPyObject, PyAny, PyErr, PyResult};
 
 use crate::array::{PyArray, PyArrayMethods};
 use crate::convert::NpyIndex;
@@ -240,11 +240,11 @@ where
 impl<'a, 'py, T: Element + 'a, D: Dimension + 'a> FromPyObject<'a, 'py>
     for PyReadonlyArray<'py, T, D>
 {
-    type Error = CastError<'a, 'py>;
+    type Error = PyErr;
 
     fn extract(obj: Borrowed<'a, 'py, PyAny>) -> Result<Self, Self::Error> {
         let array = obj.cast::<PyArray<T, D>>()?;
-        Ok(array.readonly())
+        Ok(array.try_readonly()?)
     }
 }
 
@@ -483,11 +483,11 @@ where
 impl<'a, 'py, T: Element + 'a, D: Dimension + 'a> FromPyObject<'a, 'py>
     for PyReadwriteArray<'py, T, D>
 {
-    type Error = CastError<'a, 'py>;
+    type Error = PyErr;
 
     fn extract(obj: Borrowed<'a, 'py, PyAny>) -> Result<Self, Self::Error> {
         let array = obj.cast::<PyArray<T, D>>()?;
-        Ok(array.readwrite())
+        Ok(array.try_readwrite()?)
     }
 }
 

tests/borrow.rs

@@ -6,7 +6,7 @@ use numpy::{
 };
 use pyo3::{
     ffi::c_str,
-    py_run, pyclass, pymethods,
+    pyclass, pymethods,
     types::{IntoPyDict, PyAnyMethods},
     Py, Python,
 };
@@ -97,16 +97,17 @@ impl Borrower {
 }
 
 #[test]
-#[should_panic(expected = "AlreadyBorrowed")]
 fn borrows_span_frames() {
     Python::attach(|py| {
         let borrower = Py::new(py, Borrower).unwrap();
+        let borrower = borrower.bind(py);
 
         let array = PyArray::<f64, _>::zeros(py, (1, 2, 3), false);
 
         let _exclusive = array.readwrite();
 
-        py_run!(py, borrower array, "borrower.exclusive(array)");
+        let locals = [("borrower", borrower.as_any()), ("array", array.as_any())].into_py_dict(py).unwrap();
+        py.run(c"borrower.exclusive(array)", Some(&locals), None).expect_err("already borrowed");
     });
 }