pythonnet
diff --git a/AUTHORS.md b/AUTHORS.md
@@ -29,6 +29,7 @@
 -   Sean Freitag ([@cowboygneox](https://github.com/cowboygneox))
 -   Serge Weinstock ([@sweinst](https://github.com/sweinst))
 -   Virgil Dupras ([@hsoft](https://github.com/hsoft))
+-   Wenguang Yang ([@yagweb](https://github.com/yagweb))
 -   Xavier Dupré ([@sdpython](https://github.com/sdpython))
 -   Zane Purvis ([@zanedp](https://github.com/zanedp))
 -   ([@ArvidJB](https://github.com/ArvidJB))

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -15,6 +15,8 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 -   Added Embedded tests on Appveyor (#353)
 -   Added PY3 settings to configuration-manager (#346)
 -   Added `Slack` chat (#384)(#383)(#386)
+-   Added function of passing an arbitrary .NET object as the value
+    of an attribute of PyObject (#370)(#373)
 
 ### Changed
 

diff --git a/src/embed_tests/Python.EmbeddingTest.csproj b/src/embed_tests/Python.EmbeddingTest.csproj
@@ -65,6 +65,7 @@
     <DebugType>pdbonly</DebugType>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Microsoft.CSharp" />
     <Reference Include="nunit.framework, Version=3.6.0.0, Culture=neutral, PublicKeyToken=2638cd05610744eb, processorArchitecture=MSIL">
       <HintPath>..\..\packages\NUnit.3.6.0\lib\net40\nunit.framework.dll</HintPath>
     </Reference>
@@ -76,6 +77,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="pyinitialize.cs" />
+    <Compile Include="dynamic.cs" />
     <Compile Include="pyimport.cs" />
     <Compile Include="pyiter.cs" />
     <Compile Include="pylong.cs" />

diff --git a/src/embed_tests/dynamic.cs b/src/embed_tests/dynamic.cs
@@ -0,0 +1,122 @@
+using System;
+using System.Text;
+using NUnit.Framework;
+using Python.Runtime;
+
+namespace Python.EmbeddingTest
+{
+    [TestFixture]
+    public class dynamicTest
+    {
+        private Py.GILState gil;
+
+        [SetUp]
+        public void SetUp()
+        {
+            gil = Py.GIL();
+        }
+
+        [TearDown]
+        public void TearDown()
+        {
+            gil.Dispose();
+        }
+
+        /// <summary>
+        /// Set the attribute of a pyobject with a .NET object.
+        /// </summary>
+        [Test]
+        public void AssignObject()
+        {
+            StringBuilder stream = new StringBuilder();
+            dynamic sys = Py.Import("sys");
+            sys.testattr = stream;
+            // Check whether there are the same object.
+            var _stream = sys.testattr.AsManagedObject(typeof(StringBuilder));
+            Assert.AreEqual(_stream, stream);
+
+            PythonEngine.RunSimpleString(
+                "import sys\n" +
+                "sys.testattr.Append('Hello!')\n");
+            Assert.AreEqual(stream.ToString(), "Hello!");
+        }
+
+        /// <summary>
+        /// Set the attribute of a pyobject to null.
+        /// </summary>
+        [Test]
+        public void AssignNone()
+        {
+            dynamic sys = Py.Import("sys");
+            sys.testattr = new StringBuilder();
+            Assert.IsNotNull(sys.testattr);
+
+            sys.testattr = null;
+            Assert.IsNull(sys.testattr);
+        }
+
+        /// <summary>
+        /// Check whether we can get the attr of a python object when the
+        /// value of attr is a PyObject.
+        /// </summary>
+        [Test]
+        public void AssignPyObject()
+        {
+            dynamic sys = Py.Import("sys");
+            dynamic io = Py.Import("io");
+            sys.testattr = io.StringIO();
+            dynamic bb = sys.testattr; //Get the PyObject
+            bb.write("Hello!");
+            Assert.AreEqual(bb.getvalue().ToString(), "Hello!");
+        }
+
+        /// <summary>
+        /// Pass the .NET object in Python side.
+        /// </summary>
+        [Test]
+        public void PassObjectInPython()
+        {
+            StringBuilder stream = new StringBuilder();
+            dynamic sys = Py.Import("sys");
+            sys.testattr1 = stream;
+
+            //Pass the .NET object in Python side
+            PythonEngine.RunSimpleString(
+                "import sys\n" +
+                "sys.testattr2 = sys.testattr1\n"
+            );
+
+            //Compare in Python
+            PythonEngine.RunSimpleString(
+                "import sys\n" +
+                "sys.testattr3 = sys.testattr1 is sys.testattr2\n"
+            );
+            Assert.AreEqual(sys.testattr3.ToString(), "True");
+
+            //Compare in .NET
+            Assert.AreEqual(sys.testattr1, sys.testattr2);
+        }
+
+        /// <summary>
+        /// Pass the PyObject in .NET side
+        /// </summary>
+        [Test]
+        public void PassPyObjectInNet()
+        {
+            StringBuilder stream = new StringBuilder();
+            dynamic sys = Py.Import("sys");
+            sys.testattr1 = stream;
+            sys.testattr2 = sys.testattr1;
+
+            //Compare in Python
+            PyObject res = PythonEngine.RunString(
+                "import sys\n" +
+                "sys.testattr3 = sys.testattr1 is sys.testattr2\n"
+            );
+            Assert.AreEqual(sys.testattr3.ToString(), "True");
+
+            //Compare in .NET
+            Assert.AreEqual(sys.testattr1, sys.testattr2);
+        }
+    }
+}
diff --git a/src/runtime/pyobject.cs b/src/runtime/pyobject.cs
@@ -887,30 +887,32 @@ public override int GetHashCode()
             return Runtime.PyObject_Hash(obj).ToInt32();
         }
 
-        public override bool TryGetMember(GetMemberBinder binder, out object result)
+
+        public long Refcount
         {
-            if (this.HasAttr(binder.Name))
-            {
-                result = CheckNone(this.GetAttr(binder.Name));
-                return true;
-            }
-            else
+            get
             {
-                return base.TryGetMember(binder, out result);
+                return Runtime.Refcount(obj);
             }
         }
 
+
+        public override bool TryGetMember(GetMemberBinder binder, out object result)
+        {
+            result = CheckNone(this.GetAttr(binder.Name));
+            return true;
+        }
+
         public override bool TrySetMember(SetMemberBinder binder, object value)
         {
-            if (this.HasAttr(binder.Name))
-            {
-                this.SetAttr(binder.Name, (PyObject)value);
-                return true;
-            }
-            else
+            IntPtr ptr = Converter.ToPython(value, value?.GetType());
+            int r = Runtime.PyObject_SetAttrString(obj, binder.Name, ptr);
+            if (r < 0)
             {
-                return base.TrySetMember(binder, value);
+                throw new PythonException();
             }
+            Runtime.XDecref(ptr);
+            return true;
         }
 
         private void GetArgs(object[] inargs, out PyTuple args, out PyDict kwargs)