@@ -86,6 +86,7 @@
     <Compile Include="pyiter.cs" />
     <Compile Include="pylong.cs" />
     <Compile Include="pyobject.cs" />
+    <Compile Include="pyrunstring.cs" />
     <Compile Include="pythonexception.cs" />
     <Compile Include="pytuple.cs" />
   </ItemGroup>
 
@@ -0,0 +1,61 @@
+using System;
+using NUnit.Framework;
+using Python.Runtime;
+
+namespace Python.EmbeddingTest
+{
+    public class RunStringTest
+    {
+        private Py.GILState gil;
+
+        [SetUp]
+        public void SetUp()
+        {
+            gil = Py.GIL();
+        }
+
+        [TearDown]
+        public void Dispose()
+        {
+            gil.Dispose();
+        }
+
+        [Test]
+        public void TestRunSimpleString()
+        {
+            int aa = PythonEngine.RunSimpleString("import sys");
+            Assert.AreEqual(aa, 0);
+
+            int bb = PythonEngine.RunSimpleString("import 1234");
+            Assert.AreEqual(bb, -1);
+        }
+
+        [Test]
+        public void TestEval()
+        {
+            dynamic sys = Py.Import("sys");
+            sys.attr1 = 100;
+            var locals = new PyDict();
+            locals.SetItem("sys", sys);
+            locals.SetItem("a", new PyInt(10));
+
+            object b = PythonEngine.Eval("sys.attr1 + a + 1", null, locals.Handle)
+                .AsManagedObject(typeof(Int32));
+            Assert.AreEqual(b, 111);
+        }
+
+        [Test]
+        public void TestExec()
+        {
+            dynamic sys = Py.Import("sys");
+            sys.attr1 = 100;
+            var locals = new PyDict();
+            locals.SetItem("sys", sys);
+            locals.SetItem("a", new PyInt(10));
+
+            PythonEngine.Exec("c = sys.attr1 + a + 1", null, locals.Handle);
+            object c = locals.GetItem("c").AsManagedObject(typeof(Int32));
+            Assert.AreEqual(c, 111);
+        }
+    }
+}
@@ -156,11 +156,7 @@ public static void Initialize(IEnumerable<string> args)
                 string code =
                     "import atexit, clr\n" +
                     "atexit.register(clr._AtExit)\n";
-                PyObject r = PythonEngine.RunString(code);
-                if (r != null)
-                {
-                    r.Dispose();
-                }
+                PythonEngine.Exec(code);
 
                 // Load the clr.py resource into the clr module
                 IntPtr clr = Python.Runtime.ImportHook.GetCLRModule();
@@ -180,12 +176,7 @@ public static void Initialize(IEnumerable<string> args)
                     {
                         // add the contents of clr.py to the module
                         string clr_py = reader.ReadToEnd();
-                        PyObject result = RunString(clr_py, module_globals, locals.Handle);
-                        if (null == result)
-                        {
-                            throw new PythonException();
-                        }
-                        result.Dispose();
+                        Exec(clr_py, module_globals, locals.Handle);
                     }
 
                     // add the imported module to the clr module, and copy the API functions
@@ -253,11 +244,7 @@ public static void InitExt()
                     "            exec(line)\n" +
                     "            break\n";
 
-                PyObject r = PythonEngine.RunString(code);
-                if (r != null)
-                {
-                    r.Dispose();
-                }
+                PythonEngine.Exec(code);
             }
             catch (PythonException e)
             {
@@ -405,6 +392,38 @@ public static PyObject ModuleFromString(string name, string code)
         }
 
 
+        /// <summary>
+        /// Eval Method
+        /// </summary>
+        /// <remarks>
+        /// Evaluate a Python expression and returns the result.
+        /// It's a subset of Python eval function.
+        /// </remarks>
+        public static PyObject Eval(string code, IntPtr? globals = null, IntPtr? locals = null)
+        {
+            PyObject result = RunString(code, globals, locals, RunFlagType.Eval);
+            return result;
+        }
+
+
+        /// <summary>
+        /// Exec Method
+        /// </summary>
+        /// <remarks>
+        /// Run a string containing Python code.
+        /// It's a subset of Python exec function.
+        /// </remarks>
+        public static void Exec(string code, IntPtr? globals = null, IntPtr? locals = null)
+        {
+            PyObject result = RunString(code, globals, locals, RunFlagType.File);
+            if (result.obj != Runtime.PyNone)
+            {
+                throw new PythonException();
+            }
+            result.Dispose();
+        }
+
+
         /// <summary>
         /// RunString Method
         /// </summary>
@@ -413,8 +432,8 @@ public static PyObject ModuleFromString(string name, string code)
         /// executing the code string as a PyObject instance, or null if
         /// an exception was raised.
         /// </remarks>
-        public static PyObject RunString(
-            string code, IntPtr? globals = null, IntPtr? locals = null
+        internal static PyObject RunString(
+            string code, IntPtr? globals = null, IntPtr? locals = null, RunFlagType _flag = RunFlagType.File
         )
         {
             var borrowedGlobals = true;
@@ -439,7 +458,7 @@ public static PyObject RunString(
                 borrowedLocals = false;
             }
 
-            var flag = (IntPtr)257; /* Py_file_input */
+            var flag = (IntPtr)_flag;
 
             try
             {
@@ -465,6 +484,13 @@ public static PyObject RunString(
         }
     }
 
+    public enum RunFlagType
+    {
+        Single = 256,
+        File = 257, /* Py_file_input */
+        Eval = 258
+    }
+
     public static class Py
     {
         public static GILState GIL()