Fixing python object for obtaining scalars (#330)

* Fixing python object for obtaining scalars

Signed-off-by: shams <shamsazeem20@gmail.com>

* Fix variable name for stridePtr

Signed-off-by: shams <shamsazeem20@gmail.com>

* Fix variable name for stridePtr

Signed-off-by: shams <shamsazeem20@gmail.com>

Co-authored-by: Alex Black <blacka101@gmail.com>

datavec/datavec-python/src/main/java/org/datavec/python/PythonObject.java

@@ -77,7 +77,7 @@ public class PythonObject {
 
         long address = bp.address();
         long size = bp.capacity();
-        NumpyArray npArr = NumpyArray.builder().address(address).shape(new long[]{size}).strides(new long[]{1}).dtype(DataType.BYTE).build();
+        NumpyArray npArr = NumpyArray.builder().address(address).shape(new long[]{size}).strides(new long[]{1}).dtype(DataType.INT8).build();
         nativePythonObject = Python.memoryview(new PythonObject(npArr)).nativePythonObject;
     }
 
@@ -320,20 +320,23 @@ public class PythonObject {
     public NumpyArray toNumpy() throws PythonException{
         PyObject np = PyImport_ImportModule("numpy");
         PyObject ndarray = PyObject_GetAttrString(np, "ndarray");
-        if (PyObject_IsInstance(nativePythonObject, ndarray) == 0){
+        if (PyObject_IsInstance(nativePythonObject, ndarray) != 1){
             throw new PythonException("Object is not a numpy array! Use Python.ndarray() to convert object to a numpy array.");
         }
         Py_DecRef(ndarray);
         Py_DecRef(np);
+
         Pointer objPtr = new Pointer(nativePythonObject);
         PyArrayObject npArr = new PyArrayObject(objPtr);
         Pointer ptr = PyArray_DATA(npArr);
-        SizeTPointer shapePtr = PyArray_SHAPE(npArr);
         long[] shape = new long[PyArray_NDIM(npArr)];
-        shapePtr.get(shape, 0, shape.length);
+        SizeTPointer shapePtr = PyArray_SHAPE(npArr);
-        SizeTPointer stridesPtr = PyArray_STRIDES(npArr);
+        if (shapePtr != null)
+            shapePtr.get(shape, 0, shape.length);
         long[] strides = new long[shape.length];
-        stridesPtr.get(strides, 0, strides.length);
+        SizeTPointer stridesPtr = PyArray_STRIDES(npArr);
+        if (stridesPtr != null)
+            stridesPtr.get(strides, 0, strides.length);
         int npdtype = PyArray_TYPE(npArr);
 
         DataType dtype;
@@ -345,28 +348,27 @@ public class PythonObject {
             case NPY_SHORT:
                 dtype = DataType.SHORT; break;
             case NPY_INT:
-                dtype = DataType.INT; break;
+                dtype = DataType.INT32; break;
             case NPY_LONG:
                 dtype = DataType.LONG; break;
             case NPY_UINT:
                 dtype = DataType.UINT32; break;
             case NPY_BYTE:
-                dtype = DataType.BYTE; break;
+                dtype = DataType.INT8; break;
             case NPY_UBYTE:
-                dtype = DataType.UBYTE; break;
+                dtype = DataType.UINT8; break;
             case NPY_BOOL:
                 dtype = DataType.BOOL; break;
             case NPY_HALF:
-                dtype = DataType.HALF; break;
+                dtype = DataType.FLOAT16; break;
             case NPY_LONGLONG:
                 dtype = DataType.INT64; break;
             case NPY_USHORT:
                 dtype = DataType.UINT16; break;
             case NPY_ULONG:
-                dtype = DataType.UINT64; break;
             case NPY_ULONGLONG:
                 dtype = DataType.UINT64; break;
-                default:
+            default:
                     throw new PythonException("Unsupported array data type: " + npdtype);
         }
 

datavec/datavec-python/src/test/java/org/datavec/python/ScalarAndArrayTest.java

@@ -0,0 +1,48 @@
+/* ******************************************************************************
+ * Copyright (c) 2020 Konduit K.K.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+package org.datavec.python;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.nd4j.linalg.api.ndarray.INDArray;
+import org.nd4j.linalg.factory.Nd4j;
+
+import static junit.framework.TestCase.assertEquals;
+
+@RunWith(Parameterized.class)
+public class ScalarAndArrayTest {
+
+    @Parameterized.Parameters(name = "{index}: Testing with INDArray={0}")
+    public static INDArray[] data() {
+        return new INDArray[]{
+                Nd4j.scalar(10),
+                Nd4j.ones(10, 10, 10, 10)
+        };
+    }
+
+    private INDArray indArray;
+
+    public ScalarAndArrayTest(INDArray indArray) {
+        this.indArray = indArray;
+    }
+
+    @Test
+    public void testINDArray() throws PythonException {
+        assertEquals(indArray, new PythonObject(indArray).toNumpy().getNd4jArray());
+    }
+}