numpy · hypercubestart · Sep 17, 2019 · Sep 17, 2019 · Sep 17, 2019 · Sep 17, 2019
diff --git a/numpy/core/src/multiarray/common.c b/numpy/core/src/multiarray/common.c
@@ -429,7 +429,7 @@ PyArray_DTypeFromObjectHelper(PyObject *obj, int maxdims,
      * be treated as objects, and they expect numpy to treat it as an object if
      * __len__ is not defined.
      */
-    if (maxdims == 0 || !PySequence_Check(obj) || PySequence_Size(obj) < 0) {
+    if (maxdims == 0 || !PyArray_SequenceOrMappingViewCheck(obj) || PySequence_Size(obj) < 0) {
         /* clear any PySequence_Size error which corrupts further calls */
         PyErr_Clear();
 

diff --git a/numpy/core/src/multiarray/common.h b/numpy/core/src/multiarray/common.h
@@ -129,6 +129,35 @@ check_and_adjust_index(npy_intp *index, npy_intp max_item, int axis,
     return 0;
 }
 
+/*
+ * Returns 1 if *obj is array-like object, otherwise returns 0
+ */
+static NPY_INLINE int
+PyArray_SequenceOrMappingViewCheck(PyObject *obj) {
+    /* Check is *obj is sequence*/
+    if (PySequence_Check(obj)) {
+        return 1;
+    }
+
+    /* Check is *obj inherits collections.abc.MappingView */
+    static PyObject *mappingview = NULL;
+
+    if (mappingview == NULL) {
+        PyObject *mod = PyImport_ImportModule("collections.abc");
+
+        if (mod != NULL) {
+            mappingview = PyObject_GetAttrString(mod, "MappingView");
+            Py_DECREF(mod);
+        }
+    }
+
+    if (PyObject_IsInstance(obj, mappingview) == 1) {
+        return 1;
+    }
+
+    return 0;
+}
+
 /*
  * Returns -1 and sets an exception if *axis is an invalid axis for
  * an array of dimension ndim, otherwise adjusts it in place to be

diff --git a/numpy/core/src/multiarray/compiled_base.c b/numpy/core/src/multiarray/compiled_base.c
@@ -859,7 +859,7 @@ astype_anyint(PyObject *obj) {
             return NULL;
         }
         if (dtype_guess == NULL) {
-            if (PySequence_Check(obj) && PySequence_Size(obj) == 0) {
+            if (PyArray_SequenceOrMappingViewCheck(obj) && PySequence_Size(obj) == 0) {
                 PyErr_SetString(PyExc_TypeError, EMPTY_SEQUENCE_ERR_MSG);
             }
             return NULL;
@@ -901,7 +901,7 @@ static int int_sequence_to_arrays(PyObject *seq,
 {
     int i;
 
-    if (!PySequence_Check(seq) || PySequence_Size(seq) != count) {
+    if (!PyArray_SequenceOrMappingViewCheck(seq) || PySequence_Size(seq) != count) {
         PyErr_Format(PyExc_ValueError,
                 "parameter %s must be a sequence of length %d",
                 paramname, count);

diff --git a/numpy/core/src/multiarray/ctors.c b/numpy/core/src/multiarray/ctors.c
@@ -624,7 +624,7 @@ setArrayFromSequence(PyArrayObject *a, PyObject *s,
 NPY_NO_EXPORT int
 PyArray_AssignFromSequence(PyArrayObject *self, PyObject *v)
 {
-    if (!PySequence_Check(v)) {
+    if (!PyArray_SequenceOrMappingViewCheck(v)) {
         PyErr_SetString(PyExc_ValueError,
                         "assignment from non-sequence");
         return -1;
@@ -752,7 +752,7 @@ discover_dimensions(PyObject *obj, int *maxndim, npy_intp *d, int check_it,
     }
 
     /* obj is not a Sequence */
-    if (!PySequence_Check(obj) ||
+    if (!PyArray_SequenceOrMappingViewCheck(obj) ||
             PySequence_Length(obj) < 0) {
         *maxndim = 0;
         PyErr_Clear();
@@ -1801,7 +1801,7 @@ PyArray_GetArrayParamsFromObject(PyObject *op,
     }
 
     /* Try to treat op as a list of lists or array-like objects. */
-    if (!writeable && PySequence_Check(op)) {
+    if (!writeable && PyArray_SequenceOrMappingViewCheck(op)) {
         int check_it, stop_at_string, stop_at_tuple, is_object;
         int type_num, type;
 

diff --git a/numpy/core/tests/test_multiarray.py b/numpy/core/tests/test_multiarray.py
@@ -1101,6 +1101,22 @@ def test_jagged_shape_object(self):
         assert_equal(a.shape, (3,))
         assert_equal(a.dtype, object)
 
+    def test_mapping_view(self):
+        # Test correct array creation from dict subtypes
+        d = {0: 1, 2: 3, 4: 5}
+
+        a = np.array(d.items())
+        assert_equal(a.shape, (3,2))
+        # dtype inferred differently on Windows/Linux/Mac
+        assert_equal((a.dtype == np.int32 or a.dtype == np.int64), True) 
+
+        a = np.array(d.keys())
+        assert_equal(a.shape, (3,))
+        assert_equal((a.dtype == np.int32 or a.dtype == np.int64), True)
+
+        a = np.array(d.values())
+        assert_equal(a.shape, (3,))
+        assert_equal((a.dtype == np.int32 or a.dtype == np.int64), True)
 
 class TestStructured(object):
     def test_subarray_field_access(self):