ndarray string comparison.

src/TensorFlowNET.Core/Eager/EagerTensor.Creation.cs

@@ -60,6 +60,9 @@ namespace Tensorflow.Eager
         {
             _id = ops.uid();
             _eagerTensorHandle = c_api.TFE_NewTensorHandle(h, tf.Status.Handle);
+#if TRACK_TENSOR_LIFE
+            Console.WriteLine($"New EagerTensor {_eagerTensorHandle}");
+#endif
             tf.Status.Check(true);
         }
 

src/TensorFlowNET.Core/NumPy/NDArray.Equal.cs

@@ -16,6 +16,7 @@ namespace Tensorflow.NumPy
                 long val => GetAtIndex<long>(0) == val,
                 float val => GetAtIndex<float>(0) == val,
                 double val => GetAtIndex<double>(0) == val,
+                string val => StringData(0) == val,
                 NDArray val => Equals(this, val),
                 _ => base.Equals(obj)
             };

src/TensorFlowNET.Core/NumPy/NDArrayRender.cs

@@ -91,7 +91,7 @@ namespace Tensorflow.NumPy
                         .Take(25)
                         .Select(x => x < 32 || x > 127 ? "\\x" + x.ToString("x") : Convert.ToChar(x).ToString())) + "'";
                 else
-                    return $"['{string.Join("', '", array.StringData().Take(25))}']";
+                    return $"'{string.Join("', '", array.StringData().Take(25))}'";
             }
             else if (dtype == TF_DataType.TF_VARIANT)
             {

src/TensorFlowNET.Core/Tensorflow.Binding.csproj

@@ -51,7 +51,7 @@ tf.net 0.6x.x aligns with TensorFlow v2.6.x native library.</PackageReleaseNotes
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <DefineConstants>TRACE;DEBUG</DefineConstants>
+    <DefineConstants>TRACE;DEBUG;TRACK_TENSOR_LIFE1</DefineConstants>
     <PlatformTarget>x64</PlatformTarget>
     <DocumentationFile>TensorFlow.NET.xml</DocumentationFile>
   </PropertyGroup>

src/TensorFlowNET.Core/Tensors/SafeStringTensorHandle.cs

@@ -8,7 +8,7 @@ namespace Tensorflow
     public sealed class SafeStringTensorHandle : SafeTensorHandle
     {
         Shape _shape;
-        IntPtr _handle;
+        SafeTensorHandle _tensorHandle;
         const int TF_TSRING_SIZE = 24;
 
         protected SafeStringTensorHandle()
@@ -18,16 +18,18 @@ namespace Tensorflow
         public SafeStringTensorHandle(SafeTensorHandle handle, Shape shape)
             : base(handle.DangerousGetHandle())
         {
-            _handle = c_api.TF_TensorData(handle);
+            _tensorHandle = handle;
             _shape = shape;
+            bool success = false;
+            _tensorHandle.DangerousAddRef(ref success);
         }
 
         protected override bool ReleaseHandle()
         {
+            var _handle = c_api.TF_TensorData(_tensorHandle);
 #if TRACK_TENSOR_LIFE
-            print($"Delete StringTensorHandle 0x{handle.ToString("x16")}");
+            Console.WriteLine($"Delete StringTensorData 0x{_handle.ToString("x16")}");
 #endif
-
             for (int i = 0; i < _shape.size; i++)
             {
                 c_api.TF_StringDealloc(_handle);
@@ -35,6 +37,7 @@ namespace Tensorflow
             }
 
             SetHandle(IntPtr.Zero);
+            _tensorHandle.DangerousRelease();
 
             return true;
         }

src/TensorFlowNET.Core/Tensors/Tensor.String.cs

@@ -29,13 +29,13 @@ namespace Tensorflow
 
             var tstr = c_api.TF_TensorData(handle);
 #if TRACK_TENSOR_LIFE
-            print($"New TString 0x{handle.ToString("x16")} Data: 0x{tstr.ToString("x16")}");
+            print($"New StringTensor {handle} Data: 0x{tstr.ToString("x16")}");
 #endif
             for (int i = 0; i < buffer.Length; i++)
             {
                 c_api.TF_StringInit(tstr);
                 c_api.TF_StringCopy(tstr, buffer[i], buffer[i].Length);
-                var data = c_api.TF_StringGetDataPointer(tstr);
+                // var data = c_api.TF_StringGetDataPointer(tstr);
                 tstr += TF_TSRING_SIZE;
             }
 
@@ -53,6 +53,36 @@ namespace Tensorflow
             return _str;
         }
 
+        public string StringData(int index)
+        {
+            var bytes = StringBytes(index);
+            return Encoding.UTF8.GetString(bytes);
+        }
+
+        public byte[] StringBytes(int index)
+        {
+            if (dtype != TF_DataType.TF_STRING)
+                throw new InvalidOperationException($"Unable to call StringData when dtype != TF_DataType.TF_STRING (dtype is {dtype})");
+
+            byte[] buffer = new byte[0];
+            var tstrings = TensorDataPointer;
+            for (int i = 0; i < shape.size; i++)
+            {
+                if(index == i)
+                {
+                    var data = c_api.TF_StringGetDataPointer(tstrings);
+                    var len = c_api.TF_StringGetSize(tstrings);
+                    buffer = new byte[len];
+                    // var capacity = c_api.TF_StringGetCapacity(tstrings);
+                    // var type = c_api.TF_StringGetType(tstrings);
+                    Marshal.Copy(data, buffer, 0, Convert.ToInt32(len));
+                    break;
+                }
+                tstrings += TF_TSRING_SIZE;
+            }
+            return buffer;
+        }
+
         public byte[][] StringBytes()
         {
             if (dtype != TF_DataType.TF_STRING)

src/TensorFlowNET.Keras/Utils/np_utils.cs

@@ -22,7 +22,7 @@ namespace Tensorflow.Keras.Utils
             // categorical[np.arange(y.size), y] = 1;
             for (var i = 0; i < (int)y.size; i++)
             {
-                categorical[i][y1[i]] = 1.0f;
+                categorical[i, y1[i]] = 1.0f;
             }
 
             return categorical;

test/TensorFlowNET.UnitTest/ManagedAPI/StringsApiTest.cs

@@ -51,12 +51,11 @@ namespace TensorFlowNET.UnitTest.ManagedAPI
         {
             var strings = new[] { "map_and_batch_fusion", "noop_elimination", "shuffle_and_repeat_fusion" };
             var tensor = tf.constant(strings, dtype: tf.@string, name: "optimizations");
-            var stringData = tensor.StringData();
 
             Assert.AreEqual(3, tensor.shape[0]);
-            Assert.AreEqual(strings[0], stringData[0]);
-            Assert.AreEqual(strings[1], stringData[1]);
-            Assert.AreEqual(strings[2], stringData[2]);
+            Assert.AreEqual(tensor[0].numpy(), strings[0]);
+            Assert.AreEqual(tensor[1].numpy(), strings[1]);
+            Assert.AreEqual(tensor[2].numpy(), strings[2]);
         }
 
         [TestMethod]