Always set PythonDLL path (#11)

* Always set PythonDLL path

* Move path reset to initialization

* Add environment variable to disable PythonDLL reset.

Author: twastvedt

DSPythonNet3/DSPythonNet3CodeCompletionProviderCore.cs

@@ -71,13 +71,7 @@ import clr
 
         private object ExecutePythonScriptCode(string code)
         {
-            Task.Run(DSPythonNet3Evaluator.InstallPythonAsync).Wait();
-
-            if (!PythonEngine.IsInitialized)
-            {
-                PythonEngine.Initialize();
-                PythonEngine.BeginAllowThreads();
-            }
+            DSPythonNet3Evaluator.InitializePython();
 
             using (Py.GIL())
             {
@@ -375,13 +369,7 @@ public DSPythonNet3CodeCompletionProviderCore()
             BasicVariableTypes.Add(Tuple.Create(LIST_VARIABLE, typeof(PyList)));
             BasicVariableTypes.Add(Tuple.Create(DICT_VARIABLE, typeof(PyDict)));
 
-            Task.Run(DSPythonNet3Evaluator.InstallPythonAsync).Wait();
-
-            if (!PythonEngine.IsInitialized)
-            {
-                PythonEngine.Initialize();
-                PythonEngine.BeginAllowThreads();
-            }
+            DSPythonNet3Evaluator.InitializePython();
 
             try
             {

DSPythonNet3/DSPythonNet3Evaluator.cs

@@ -247,71 +247,63 @@ public override object Evaluate(
                 return null;
             }
 
-            Task.Run(InstallPythonAsync).Wait();
-            if (!PythonEngine.IsInitialized)
-            {
-                PythonEngine.Initialize();
-                PythonEngine.BeginAllowThreads();
+            InitializePython();
 
-                using (Py.GIL())
-                using (PyModule scope = Py.CreateScope())
+            using (Py.GIL())
+            {
+                if (globalScope == null)
                 {
-                    scope.Exec("import sys" + Environment.NewLine + "path = str(sys.path)");
-                    path = scope.Get<string>("path");
+                    globalScope = CreateGlobalScope();
                 }
-            }
-                using (Py.GIL())
-                {
-                    if (globalScope == null)
-                    {
-                        globalScope = CreateGlobalScope();
-                    }
 
-                    using (PyModule scope = Py.CreateScope())
+                using (PyModule scope = Py.CreateScope())
+                {
+                    if (path is not null)
                     {
                         // Reset the 'sys.path' value to the default python paths on node evaluation. See https://github.com/DynamoDS/Dynamo/pull/10977. 
                         var pythonNodeSetupCode = "import sys" + Environment.NewLine + $"sys.path = {path}";
                         scope.Exec(pythonNodeSetupCode);
+                    }
 
-                        ProcessAdditionalBindings(scope, bindingNames, bindingValues);
+                    ProcessAdditionalBindings(scope, bindingNames, bindingValues);
 
-                        int amt = Math.Min(bindingNames.Count, bindingValues.Count);
+                    int amt = Math.Min(bindingNames.Count, bindingValues.Count);
 
-                        for (int i = 0; i < amt; i++)
-                        {
-                            scope.Set((string)bindingNames[i], InputMarshaler.Marshal(bindingValues[i]).ToPython());
-                        }
+                    for (int i = 0; i < amt; i++)
+                    {
+                        scope.Set((string)bindingNames[i], InputMarshaler.Marshal(bindingValues[i]).ToPython());
+                    }
 
-                        try
-                        {
-                            OnEvaluationBegin(scope, code, bindingValues);
-                            scope.Exec(code);
-                            var result = scope.Contains("OUT") ? scope.Get("OUT") : null;
+                    try
+                    {
+                        OnEvaluationBegin(scope, code, bindingValues);
+                        scope.Exec(code);
+                        var result = scope.Contains("OUT") ? scope.Get("OUT") : null;
 
-                            return OutputMarshaler.Marshal(result);
+                        return OutputMarshaler.Marshal(result);
+                    }
+                    catch (Exception e)
+                    {
+                        evaluationSuccess = false;
+                        var traceBack = GetTraceBack(e);
+                        if (!string.IsNullOrEmpty(traceBack))
+                        {
+                            // Throw a new error including trace back info added to the message
+                            throw new InvalidOperationException($"{e.Message}\n{traceBack}", e);
                         }
-                        catch (Exception e)
+                        else
                         {
-                            evaluationSuccess = false;
-                            var traceBack = GetTraceBack(e);
-                            if (!string.IsNullOrEmpty(traceBack))
-                            {
-                                // Throw a new error including trace back info added to the message
-                                throw new InvalidOperationException($"{e.Message}\n{traceBack}", e);
-                            }
-                            else
-                            {
 #pragma warning disable CA2200 // Rethrow to preserve stack details
-                                throw e;
+                            throw e;
 #pragma warning restore CA2200 // Rethrow to preserve stack details
-                            }
-                        }
-                        finally
-                        {
-                            OnEvaluationEnd(evaluationSuccess, scope, code, bindingValues);
                         }
                     }
+                    finally
+                    {
+                        OnEvaluationEnd(evaluationSuccess, scope, code, bindingValues);
+                    }
                 }
+            }
         }
 
         public static object EvaluatePythonScript(
@@ -334,12 +326,6 @@ internal static async Task InstallPythonAsync()
             {
                 try
                 {
-                    // First try the custom ways of supplying the python dll name (environment variables, or static API calls)
-                    if (string.IsNullOrEmpty(Runtime.PythonDLL))
-                    {
-                        Runtime.PythonDLL = Python.Included.Installer.PYTHON_VERSION + ".dll";
-                    }
-                    
                     var disableEmbedded = !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("DYN_DISABLE_PYNET_EMBEDDED"));
                     if (disableEmbedded)
                     {
@@ -363,6 +349,38 @@ internal static async Task InstallPythonAsync()
             }
         }
 
+        private static string path;
+
+        /// <summary>
+        /// Install, if necessary, and initialize, if necessary, Python.
+        /// </summary>
+        /// <returns>True if Python was not already initialized</returns>
+        internal static bool InitializePython()
+        {
+            Task.Run(InstallPythonAsync).Wait();
+
+            if (!PythonEngine.IsInitialized)
+            {
+                if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("DYN_DISABLE_PYTHONDLL_OVERRIDE")))
+                {
+                    Runtime.PythonDLL = Path.Join(Python.Included.Installer.EmbeddedPythonHome, Python.Included.Installer.PYTHON_VERSION + ".dll");
+                }
+
+                PythonEngine.Initialize();
+                PythonEngine.BeginAllowThreads();
+
+                using (Py.GIL())
+                using (PyModule scope = Py.CreateScope())
+                {
+                    scope.Exec("import sys" + Environment.NewLine + "path = str(sys.path)");
+                    path = scope.Get<string>("path");
+                }
+
+                return true;
+            }
+            return false;
+        }
+
         /// <summary>
         /// Creates and initializes the global Python scope.
         /// </summary>
@@ -674,7 +692,6 @@ private static bool IsMarkedToSkipConversion(PyObject pyObj)
 
         private DataMarshaler inputMarshaler;
         private DataMarshaler outputMarshaler;
-        private string path;
 
         #endregion