added isinstance (#358)

src/TensorFlowNET.Core/Keras/BackendBase.cs

@@ -15,6 +15,7 @@
 ******************************************************************************/
 
 using System;
+using static Tensorflow.Python;
 
 namespace Tensorflow.Keras
 {
@@ -43,9 +44,9 @@ namespace Tensorflow.Keras
         {
             if (value == null)
                 value = _IMAGE_DATA_FORMAT;
-            if (value.GetType() == typeof(ImageDataFormat))
+            if (isinstance(value, typeof(ImageDataFormat)))
                 return (ImageDataFormat)value;
-            else if (value.GetType() == typeof(string))
+            else if (isinstance(value, typeof(string)))
             {
                 ImageDataFormat dataFormat;
                 if(Enum.TryParse((string)value, true, out dataFormat))

src/TensorFlowNET.Core/Operations/OpDefLibrary.cs

@@ -141,7 +141,7 @@ namespace Tensorflow
                             dtype = input_arg.Type;
                         else if (attrs.ContainsKey(input_arg.TypeAttr))
                             dtype = (DataType)attrs[input_arg.TypeAttr];
-                        else if (values.GetType() == typeof(string) && dtype == DataType.DtInvalid)
+                        else if (isinstance(values, typeof(string)) && dtype == DataType.DtInvalid)
                             dtype = DataType.DtString;
                         else if (default_type_attr_map.ContainsKey(input_arg.TypeAttr))
                             default_dtype = (DataType)default_type_attr_map[input_arg.TypeAttr];

src/TensorFlowNET.Core/Python.cs

@@ -309,6 +309,36 @@ namespace Tensorflow
             }
             return (__object__)((object[] args) => { return "NaN"; });
         }
+        public static IEnumerable TupleToEnumerable(object tuple)
+        {
+            Type t = tuple.GetType();
+            if(t.IsGenericType && (t.FullName.StartsWith("System.Tuple") || t.FullName.StartsWith("System.ValueTuple")))
+            {
+                var flds = t.GetFields();
+                for(int i = 0; i < flds.Length;i++)
+                {
+                    yield return ((object)flds[i].GetValue(tuple));
+                }
+            }
+            else
+            {
+                throw new System.Exception("Expected Tuple.");
+            }
+        }
+        public static bool isinstance(object Item1, Type Item2)
+        {
+            return (Item1.GetType() == Item2);
+        }
+        public static bool isinstance(object Item1, object tuple)
+        {
+            var tup = TupleToEnumerable(tuple);
+            foreach(var t in tup)
+            {
+                if(isinstance(Item1, (Type)t))
+                    return true;
+            }
+            return false;
+        }
     }
 
     public interface IPython : IDisposable

test/TensorFlowNET.UnitTest/PythonBaseTests.cs

@@ -25,6 +25,31 @@ namespace TensorFlowNET.UnitTest
             Assert.IsTrue(b);
         }
 
+        [TestMethod]
+        public void isinstance_test()
+        {
+            var s1 = "hi";
+            var s2 = "hello";
+
+            var t1 = (s1, s2);
+            var t2 = (s1, s2, s1);
+            var t3 = (s2, s1);
+
+            var true1 = isinstance(s1, typeof(string));
+            var false1 = isinstance(t1, typeof(string));
+            var true2 = isinstance(t1, t3.GetType());
+            var false2 = isinstance(t1, t2.GetType());
+            var true3 = isinstance(t1, (t2.GetType(), t1.GetType(), typeof(string)));
+            var false3 = isinstance(t3, (t2.GetType(), typeof(string)));
+
+            Assert.IsTrue(true1);
+            Assert.IsTrue(true2);
+            Assert.IsTrue(true3);
+            Assert.IsFalse(false1);
+            Assert.IsFalse(false2);
+            Assert.IsFalse(false3);
+        }
+
         [TestMethod]
         public void hasattr_getattr()
         {