Introduce PyArrayDescr

Author: kngwyu

src/array.rs

@@ -103,7 +103,7 @@ impl<T, D> type_object::PySizedLayout<PyArray<T, D>> for npyffi::PyArrayObject {
 pyobject_native_type_convert!(
     PyArray<T, D>,
     npyffi::PyArrayObject,
-    *npyffi::PY_ARRAY_API.get_type_object(npyffi::ArrayType::PyArray_Type),
+    *npyffi::PY_ARRAY_API.get_type_object(npyffi::NpyTypes::PyArray_Type),
     Some("numpy"),
     npyffi::PyArray_Check,
     T, D
@@ -386,7 +386,7 @@ impl<T: Element, D: Dimension> PyArray<T, D> {
     {
         let dims = dims.into_dimension();
         let ptr = PY_ARRAY_API.PyArray_New(
-            PY_ARRAY_API.get_type_object(npyffi::ArrayType::PyArray_Type),
+            PY_ARRAY_API.get_type_object(npyffi::NpyTypes::PyArray_Type),
             dims.ndim_cint(),
             dims.as_dims_ptr(),
             T::ffi_dtype() as i32,
@@ -415,7 +415,7 @@ impl<T: Element, D: Dimension> PyArray<T, D> {
             .create_cell(py)
             .expect("Object creation failed.");
         let ptr = PY_ARRAY_API.PyArray_New(
-            PY_ARRAY_API.get_type_object(npyffi::ArrayType::PyArray_Type),
+            PY_ARRAY_API.get_type_object(npyffi::NpyTypes::PyArray_Type),
             dims.ndim_cint(),
             dims.as_dims_ptr(),
             T::ffi_dtype() as i32,

src/dtype.rs

@@ -0,0 +1,23 @@
+use crate::npyffi::{NpyTypes, PyArray_Descr, PY_ARRAY_API};
+use pyo3::ffi;
+use pyo3::prelude::*;
+use std::os::raw::c_int;
+
+pub struct PyArrayDescr(PyAny);
+
+pyobject_native_type_core!(
+    PyArrayDescr,
+    PyArray_Descr,
+    *PY_ARRAY_API.get_type_object(NpyTypes::PyArrayDescr_Type),
+    Some("numpy"),
+    arraydescr_check
+);
+
+pyobject_native_type_fmt!(PyArrayDescr);
+
+unsafe fn arraydescr_check(op: *mut ffi::PyObject) -> c_int {
+    ffi::PyObject_TypeCheck(
+        op,
+        PY_ARRAY_API.get_type_object(NpyTypes::PyArrayDescr_Type),
+    )
+}

src/lib.rs

@@ -38,6 +38,7 @@ extern crate pyo3;
 
 pub mod array;
 pub mod convert;
+mod dtype;
 mod error;
 pub mod npyffi;
 pub mod npyiter;
@@ -50,6 +51,7 @@ pub use crate::array::{
     PyArrayDyn,
 };
 pub use crate::convert::{IntoPyArray, NpyIndex, ToNpyDims, ToPyArray};
+pub use crate::dtype::PyArrayDescr;
 pub use crate::error::{FromVecError, NotContiguousError, ShapeError};
 pub use crate::npyffi::{PY_ARRAY_API, PY_UFUNC_API};
 pub use crate::npyiter::{

src/npyffi/array.rs

@@ -320,20 +320,19 @@ macro_rules! impl_array_type {
     ($(($offset:expr, $tname:ident)),*) => {
         /// All type objects that numpy has.
         #[allow(non_camel_case_types)]
-        #[repr(i32)]
-        pub enum ArrayType { $($tname),* }
+        pub enum NpyTypes { $($tname),* }
         impl PyArrayAPI {
             /// Get the pointer of the type object that `self` refers.
-            pub unsafe fn get_type_object(&self, ty: ArrayType) -> *mut PyTypeObject {
+            pub unsafe fn get_type_object(&self, ty: NpyTypes) -> *mut PyTypeObject {
                 match ty {
-                    $( ArrayType::$tname => *(self.get($offset)) as *mut PyTypeObject ),*
+                    $( NpyTypes::$tname => *(self.get($offset)) as _ ),*
                 }
             }
         }
     }
-} // impl_array_type!;
+}
 
-impl_array_type!(
+impl_array_type! {
     (1, PyBigArray_Type),
     (2, PyArray_Type),
     (3, PyArrayDescr_Type),
@@ -373,18 +372,18 @@ impl_array_type!(
     (37, PyStringArrType_Type),
     (38, PyUnicodeArrType_Type),
     (39, PyVoidArrType_Type)
-);
+}
 
 /// Checks that `op` is an instance of `PyArray` or not.
 #[allow(non_snake_case)]
 pub unsafe fn PyArray_Check(op: *mut PyObject) -> c_int {
-    ffi::PyObject_TypeCheck(op, PY_ARRAY_API.get_type_object(ArrayType::PyArray_Type))
+    ffi::PyObject_TypeCheck(op, PY_ARRAY_API.get_type_object(NpyTypes::PyArray_Type))
 }
 
 /// Checks that `op` is an exact instance of `PyArray` or not.
 #[allow(non_snake_case)]
 pub unsafe fn PyArray_CheckExact(op: *mut PyObject) -> c_int {
-    (ffi::Py_TYPE(op) == PY_ARRAY_API.get_type_object(ArrayType::PyArray_Type)) as c_int
+    (ffi::Py_TYPE(op) == PY_ARRAY_API.get_type_object(NpyTypes::PyArray_Type)) as _
 }
 
 #[test]

tests/array.rs

@@ -234,3 +234,17 @@ fn handle_negative_strides() {
         .unwrap();
     assert_eq!(negstr_pyarr.to_owned_array(), arr.slice(s![..;-1, ..]));
 }
+
+#[test]
+fn dtype_from_py() {
+    let gil = pyo3::Python::acquire_gil();
+    let py = gil.python();
+    let arr = array![[2, 3], [4, 5u32]];
+    let pyarr = arr.to_pyarray(py);
+    let dtype: &numpy::PyArrayDescr = py
+        .eval("a.dtype", Some([("a", pyarr)].into_py_dict(py)), None)
+        .unwrap()
+        .downcast()
+        .unwrap();
+    assert_eq!(&format!("{:?}", dtype), "dtype('uint32')");
+}