do not make newly created arrays immutable

Author: flexatone

src/methods.c

@@ -247,7 +247,7 @@ is_objectable(PyObject *m, PyObject *a) {
     Py_RETURN_TRUE;
 }
 
-
+// Convert array to the dtype provided. NOTE: mutable arrays will be returned unless the input array is immutable and no dtype change is needed
 PyObject*
 astype_array(PyObject* m, PyObject* args) {
 
@@ -272,12 +272,12 @@ astype_array(PyObject* m, PyObject* args) {
 
     if (PyArray_EquivTypes(PyArray_DESCR(array), dtype)) {
         Py_DECREF(dtype);
+
         if (PyArray_ISWRITEABLE(array)) {
             PyObject* result = PyArray_NewCopy(array, NPY_ANYORDER);
             if (!result) {
                 return NULL;
             }
-            PyArray_CLEARFLAGS((PyArrayObject *)result, NPY_ARRAY_WRITEABLE);
             return result;
         }
         else { // already immutable
@@ -319,7 +319,6 @@ astype_array(PyObject* m, PyObject* args) {
                     PyArray_ITER_NEXT(it);
                 }
                 Py_DECREF(it);
-                PyArray_CLEARFLAGS((PyArrayObject *)result, NPY_ARRAY_WRITEABLE);
                 return result;
             }
         }
@@ -330,7 +329,6 @@ astype_array(PyObject* m, PyObject* args) {
         Py_DECREF(dtype);
         return NULL;
     }
-    PyArray_CLEARFLAGS((PyArrayObject *)result, NPY_ARRAY_WRITEABLE);
     return result;
 }
 

test/test_astype_array.py

@@ -28,14 +28,14 @@ def test_astype_array_a3(self) -> None:
 
         a2 = astype_array(a1, np.int8)
         self.assertEqual(a2.dtype, np.dtype(np.int8))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
 
     def test_astype_array_b1(self) -> None:
         a1 = np.array(['2021', '2024'], dtype=np.datetime64)
 
         a2 = astype_array(a1, np.object_)
         self.assertEqual(a2.dtype, np.dtype(np.object_))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
         self.assertEqual(list(a2), [np.datetime64('2021'), np.datetime64('2024')])
 
 
@@ -44,7 +44,7 @@ def test_astype_array_b2(self) -> None:
 
         a2 = astype_array(a1, np.object_)
         self.assertEqual(a2.dtype, np.dtype(np.object_))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
         self.assertEqual(list(a2), [np.datetime64('2021'), np.datetime64('1642')])
 
 
@@ -53,7 +53,7 @@ def test_astype_array_b3(self) -> None:
 
         a2 = astype_array(a1, np.object_)
         self.assertEqual(a2.dtype, np.dtype(np.object_))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
         self.assertEqual(
                 list(list(a) for a in a2),
                 [[np.datetime64('2021'), np.datetime64('2024')], [np.datetime64('1984'), np.datetime64('1642')]])
@@ -64,7 +64,7 @@ def test_astype_array_b4(self) -> None:
         a2 = astype_array(a1, np.object_)
         self.assertEqual(a2.dtype, np.dtype(np.object_))
         self.assertEqual(a2.shape, (2, 3))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
         self.assertEqual(
                 list(list(a) for a in a2),
                 [[np.datetime64('2021'), np.datetime64('2024'), np.datetime64('1532')],
@@ -81,7 +81,7 @@ def test_astype_array_d1(self) -> None:
 
         self.assertEqual(a2.dtype, np.dtype(np.float64))
         self.assertEqual(a2.shape, (3,))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
 
 
     def test_astype_array_d2(self) -> None:
@@ -90,7 +90,7 @@ def test_astype_array_d2(self) -> None:
 
         self.assertEqual(a2.dtype, np.dtype(np.float64))
         self.assertEqual(a2.shape, (3,))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
 
 
 
@@ -100,7 +100,7 @@ def test_astype_array_d3(self) -> None:
 
         self.assertEqual(a2.dtype, np.dtype(np.int64))
         self.assertEqual(a2.shape, (3,))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
 
         self.assertNotEqual(id(a1), id(a2))
 
@@ -110,7 +110,7 @@ def test_astype_array_e(self) -> None:
         a2 = astype_array(a1, np.object_)
         self.assertEqual(a2.dtype, np.dtype(np.object_))
         self.assertEqual(a2.shape, (2, 3))
-        self.assertFalse(a2.flags.writeable)
+        self.assertTrue(a2.flags.writeable)
         self.assertEqual(
                 list(list(a) for a in a2),
                 [[np.datetime64('2021-01-01T00:00:00.000000000'),