Add ability to create module from .NET

slide · web-flow · commit 95552489461f · 2021-07-28T22:39:18.000-07:00
New module can be created using new `PyModule(string name, string filename)` constructor.

Also:
`Runtime.Builtins` returns dictionary, containing system builtins (e.g. `builtins` module)
`PyModule.SysModules` returns dictionary, that represents all modules loaded by the system (e.g. `sys.modules`)
diff --git a/src/embed_tests/TestPyModule.cs b/src/embed_tests/TestPyModule.cs
@@ -0,0 +1,47 @@
+
+using System;
+
+using NUnit.Framework;
+
+using Python.Runtime;
+
+namespace Python.EmbeddingTest
+{
+    public class TestPyModule
+    {
+        [OneTimeSetUp]
+        public void SetUp()
+        {
+            PythonEngine.Initialize();
+        }
+
+        [OneTimeTearDown]
+        public void Dispose()
+        {
+            PythonEngine.Shutdown();
+        }
+
+        [Test]
+        public void TestCreate()
+        {
+            using PyScope scope = Py.CreateScope();
+
+            Assert.IsFalse(PyModule.SysModules.HasKey("testmod"));
+
+            PyModule testmod = new PyModule("testmod");
+
+            testmod.SetAttr("testattr1", "True".ToPython());
+
+            PyModule.SysModules.SetItem("testmod", testmod);
+
+            using PyObject code = PythonEngine.Compile(
+                "import testmod\n" +
+                "x = testmod.testattr1"
+                );
+            scope.Execute(code);
+
+            Assert.IsTrue(scope.TryGet("x", out dynamic x));
+            Assert.AreEqual("True", x.ToString());
+        }
+    }
+}
diff --git a/src/runtime/pymodule.cs b/src/runtime/pymodule.cs
@@ -1,11 +1,15 @@
 using System;
+using System.Text;
+
+using Python.Runtime.Native;
 
 namespace Python.Runtime
 {
     public class PyModule : PyScope
     {
         internal PyModule(ref NewReference reference) : base(ref reference, PyScopeManager.Global) { }
         public PyModule(PyObject o) : base(o.Reference, PyScopeManager.Global) { }
+        public PyModule(string name, string filename = null) : this(Create(name, filename)) { }
 
         /// <summary>
         /// Given a module or package name, import the
@@ -37,5 +41,49 @@ public static PyModule FromString(string name, string code)
             PythonException.ThrowIfIsNull(m);
             return new PyModule(ref m);
         }
+
+        private static PyModule Create(string name, string filename=null)
+        {
+            if(string.IsNullOrWhiteSpace(name))
+            {
+                throw new ArgumentNullException(nameof(name));
+            }
+
+            NewReference op = Runtime.PyModule_New(name);
+            PythonException.ThrowIfIsNull(op);
+
+            if (filename != null)
+            {
+                BorrowedReference globals = Runtime.PyModule_GetDict(op);
+                PythonException.ThrowIfIsNull(globals);
+                int rc = Runtime.PyDict_SetItemString(globals, "__file__", filename.ToPython().Reference);
+                PythonException.ThrowIfIsNotZero(rc);
+            }
+
+            return new PyModule(ref op);
+        }
+
+        public void SetBuiltins(PyDict builtins)
+        {
+            if(builtins == null || builtins.IsNone())
+            {
+                throw new ArgumentNullException(nameof(builtins));
+            }
+
+            BorrowedReference globals = Runtime.PyModule_GetDict(this.Reference);
+            PythonException.ThrowIfIsNull(globals);
+            int rc = Runtime.PyDict_SetItemString(globals, "__builtins__", builtins.Reference);
+            PythonException.ThrowIfIsNotZero(rc);
+        }
+
+        public static PyDict SysModules
+        {
+            get
+            {
+                BorrowedReference sysModulesRef = Runtime.PyImport_GetModuleDict();
+                PythonException.ThrowIfIsNull(sysModulesRef);
+                return new PyDict(sysModulesRef);
+            }
+        }
     }
 }
diff --git a/src/runtime/runtime.cs b/src/runtime/runtime.cs
@@ -2280,6 +2280,16 @@ internal static IntPtr GetBuiltins()
             return PyImport_Import(PyIdentifier.builtins);
         }
 
+        public static PyDict Builtins
+        {
+            get
+            {
+                BorrowedReference builtins = PyEval_GetBuiltins();
+                PythonException.ThrowIfIsNull(builtins);
+                return new PyDict(builtins);
+            }
+        }
+
         internal static class Delegates
         {
             static readonly ILibraryLoader libraryLoader = LibraryLoader.Instance;
