pythonnet · den-run-ai · May 24, 2017 · May 6, 2017 · May 6, 2017 · May 6, 2017
diff --git a/src/embed_tests/Python.EmbeddingTest.csproj b/src/embed_tests/Python.EmbeddingTest.csproj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -97,6 +97,8 @@
     <Compile Include="TestPythonException.cs" />
     <Compile Include="TestPythonEngineProperties.cs" />
     <Compile Include="TestPyTuple.cs" />
+    <Compile Include="TestNamedArguments.cs" />
+    <Compile Include="TestPyWith.cs" />
     <Compile Include="TestRuntime.cs" />
   </ItemGroup>
   <ItemGroup>
@@ -117,4 +119,4 @@
     <Copy SourceFiles="$(TargetAssembly)" DestinationFolder="$(PythonBuildDir)" />
     <!--Copy SourceFiles="$(TargetAssemblyPdb)" Condition="Exists('$(TargetAssemblyPdb)')" DestinationFolder="$(PythonBuildDir)" /-->
   </Target>
-</Project>
+</Project>
diff --git a/src/embed_tests/TestNamedArguments.cs b/src/embed_tests/TestNamedArguments.cs
@@ -0,0 +1,64 @@
+using System;
+using NUnit.Framework;
+using Python.Runtime;
+
+namespace Python.EmbeddingTest
+{
+    public class TestNamedArguments
+    {
+        [OneTimeSetUp]
+        public void SetUp()
+        {
+            PythonEngine.Initialize();
+        }
+
+        [OneTimeTearDown]
+        public void Dispose()
+        {
+            PythonEngine.Shutdown();
+        }
+
+        /// <summary>
+        /// Test named arguments support through Py.kw method
+        /// </summary>
+        [Test]
+        public void TestKeywordArgs()
+        {
+            dynamic a = CreateTestClass();
+            var result = (int)a.Test3(2, Py.kw("a4", 8));
+
+            Assert.AreEqual(12, result);
+        }
+
+
+        /// <summary>
+        /// Test keyword arguments with .net named arguments
+        /// </summary>
+        [Test]
+        public void TestNamedArgs()
+        {
+            dynamic a = CreateTestClass();
+            var result = (int)a.Test3(2, a4: 8);
+
+            Assert.AreEqual(12, result);
+        }
+
+
+
+        private static PyObject CreateTestClass()
+        {
+            var locals = new PyDict();
+
+            PythonEngine.Exec(@"
+class cmTest3:
+    def Test3(self, a1 = 1, a2 = 1, a3 = 1, a4 = 1):
+        return a1 + a2 + a3 + a4
+
+a = cmTest3()
+", null, locals.Handle);
+
+            return locals.GetItem("a");
+        }
+
+    }
+}
diff --git a/src/embed_tests/TestPyWith.cs b/src/embed_tests/TestPyWith.cs
@@ -0,0 +1,88 @@
+using System;
+using NUnit.Framework;
+using Python.Runtime;
+
+namespace Python.EmbeddingTest
+{
+    public class TestPyWith
+    {
+        [OneTimeSetUp]
+        public void SetUp()
+        {
+            PythonEngine.Initialize();
+        }
+
+        [OneTimeTearDown]
+        public void Dispose()
+        {
+            PythonEngine.Shutdown();
+        }
+
+        /// <summary>
+        /// Test that exception is raised in context manager that ignores it.
+        /// </summary>
+        [Test]
+        public void TestWithPositive()
+        {
+            var locals = new PyDict();
+
+            PythonEngine.Exec(@"
+class CmTest:
+    def __enter__(self):
+        print('Enter')
+        return self
+    def __exit__(self, t, v, tb):
+        # Exception not handled, return will be False
+        print('Exit')
+    def fail(self):
+        return 5 / 0
+
+a = CmTest()
+", null, locals.Handle);
+
+            var a = locals.GetItem("a");
+
+            try
+            {
+                Py.With(a, cmTest =>
+                {
+                    cmTest.fail();
+                });
+            }
+            catch (PythonException e)
+            {
+                Assert.IsTrue(e.Message.Contains("ZeroDivisionError"));
+            }
+        }
+
+
+        /// <summary>
+        /// Test that exception is not raised in context manager that handles it
+        /// </summary>
+        [Test]
+        public void TestWithNegative()
+        {
+            var locals = new PyDict();
+
+            PythonEngine.Exec(@"
+class CmTest:
+    def __enter__(self):
+        print('Enter')
+        return self
+    def __exit__(self, t, v, tb):
+        # Signal exception is handled by returning true
+        return True
+    def fail(self):
+        return 5 / 0
+
+a = CmTest()
+", null, locals.Handle);
+
+            var a = locals.GetItem("a");
+            Py.With(a, cmTest =>
+            {
+                cmTest.fail();
+            });
+        }
+    }
+}
diff --git a/src/runtime/pyobject.cs b/src/runtime/pyobject.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections;
 using System.Dynamic;
 using System.Linq.Expressions;
@@ -915,6 +915,34 @@ public override bool TrySetMember(SetMemberBinder binder, object value)
             return true;
         }
 
+        private void GetArgs(object[] inargs, CallInfo callInfo, out PyTuple args, out PyDict kwargs)
+        {
+            if (callInfo == null || callInfo.ArgumentNames.Count == 0)
+            {
+                GetArgs(inargs, out args, out kwargs);
+                return;
+            }
+
+            // Support for .net named arguments
+            var namedArgumentCount = callInfo.ArgumentNames.Count;
+            var regularArgumentCount = callInfo.ArgumentCount - namedArgumentCount;
+
+            var argTuple = Runtime.PyTuple_New(regularArgumentCount);
+            for (int i = 0; i < regularArgumentCount; ++i)
+            {
+                AddArgument(argTuple, i, inargs[i]);
+            }
+            args = new PyTuple(argTuple);
+
+            var namedArgs = new object[namedArgumentCount * 2];
+            for (int i = 0; i < namedArgumentCount; ++i)
+            {
+                namedArgs[i * 2] = callInfo.ArgumentNames[i];
+                namedArgs[i * 2 + 1] = inargs[regularArgumentCount + i];
+            }
+            kwargs = Py.kw(namedArgs);
+        }
+
         private void GetArgs(object[] inargs, out PyTuple args, out PyDict kwargs)
         {
             int arg_count;
@@ -925,22 +953,10 @@ private void GetArgs(object[] inargs, out PyTuple args, out PyDict kwargs)
             IntPtr argtuple = Runtime.PyTuple_New(arg_count);
             for (var i = 0; i < arg_count; i++)
             {
-                IntPtr ptr;
-                if (inargs[i] is PyObject)
-                {
-                    ptr = ((PyObject)inargs[i]).Handle;
-                    Runtime.XIncref(ptr);
-                }
-                else
-                {
-                    ptr = Converter.ToPython(inargs[i], inargs[i]?.GetType());
-                }
-                if (Runtime.PyTuple_SetItem(argtuple, i, ptr) < 0)
-                {
-                    throw new PythonException();
-                }
+                AddArgument(argtuple, i, inargs[i]);
             }
             args = new PyTuple(argtuple);
+
             kwargs = null;
             for (int i = arg_count; i < inargs.Length; i++)
             {
@@ -959,6 +975,32 @@ private void GetArgs(object[] inargs, out PyTuple args, out PyDict kwargs)
             }
         }
 
+        private static void AddArgument(IntPtr argtuple, int i, object target)
+        {
+            IntPtr ptr = GetPythonObject(target);
+
+            if (Runtime.PyTuple_SetItem(argtuple, i, ptr) < 0)
+            {
+                throw new PythonException();
+            }
+        }
+
+        private static IntPtr GetPythonObject(object target)
+        {
+            IntPtr ptr;
+            if (target is PyObject)
+            {
+                ptr = ((PyObject)target).Handle;
+                Runtime.XIncref(ptr);
+            }
+            else
+            {
+                ptr = Converter.ToPython(target, target?.GetType());
+            }
+
+            return ptr;
+        }
+
         public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
         {
             if (this.HasAttr(binder.Name) && this.GetAttr(binder.Name).IsCallable())
@@ -967,7 +1009,7 @@ public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, o
                 PyDict kwargs = null;
                 try
                 {
-                    GetArgs(args, out pyargs, out kwargs);
+                    GetArgs(args, binder.CallInfo, out pyargs, out kwargs);
                     result = CheckNone(InvokeMethod(binder.Name, pyargs, kwargs));
                 }
                 finally
@@ -997,7 +1039,7 @@ public override bool TryInvoke(InvokeBinder binder, object[] args, out object re
                 PyDict kwargs = null;
                 try
                 {
-                    GetArgs(args, out pyargs, out kwargs);
+                    GetArgs(args, binder.CallInfo, out pyargs, out kwargs);
                     result = CheckNone(Invoke(pyargs, kwargs));
                 }
                 finally

diff --git a/src/runtime/pythonengine.cs b/src/runtime/pythonengine.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -632,5 +632,34 @@ public static void SetArgv(IEnumerable<string> argv)
                 Runtime.CheckExceptionOccurred();
             }
         }
+
+        public static void With(PyObject obj, Action<dynamic> Body)
+        {
+            // Behavior described here: 
+            // https://docs.python.org/2/reference/datamodel.html#with-statement-context-managers
+
+            IntPtr type = Runtime.PyNone;
+            IntPtr val = Runtime.PyNone;
+            IntPtr traceBack = Runtime.PyNone;
+            PythonException ex = null;
+
+            try
+            {
+                PyObject enterResult = obj.InvokeMethod("__enter__");
+
+                Body(enterResult);
+            }
+            catch (PythonException e)
+            {
+                ex = e;
+                type = ex.PyType;
+                val = ex.PyValue;
+                traceBack = ex.PyTB;
+            }
+
+            var exitResult = obj.InvokeMethod("__exit__", new PyObject(type), new PyObject(val), new PyObject(traceBack));
+
+            if (ex != null && !exitResult.IsTrue()) throw ex;
+        }
     }
 }