Remove pythonHome parameter (#19)

and update documentation

fixes #15
fixes #17

C/include/ExternalLibrary.h

@@ -14,9 +14,9 @@
 extern "C" {
 #endif
 
-EXPORT const char* externalFunction(const char *filename, const char *moduleName, const char *functionName, const char *pythonHome, int nu, const double u[], int ny, double y[]);
+EXPORT const char* externalFunction(const char *filename, const char *moduleName, const char *functionName, int nu, const double u[], int ny, double y[]);
 
-EXPORT void* createExternalObject(const char *filename, const char *moduleName, const char *className, const char *pythonHome, const ModelicaUtilityFunctions_t *callbacks);
+EXPORT void* createExternalObject(const char *filename, const char *moduleName, const char *className, const ModelicaUtilityFunctions_t *callbacks);
 
 EXPORT void evaluateExternalObject(void *externalObject, int nu, const double u[], int ny, double y[]);
 

C/src/ExternalLibraryCPP.cpp

@@ -8,10 +8,9 @@
 
 static ModelicaUtilityFunctions_t s_callbacks = { NULL };
 
-const char* externalFunction(const char *filename, const char *moduleName, const char *functionName, const char *pythonHome, int nu, const double u[], int ny, double y[]) {
+const char* externalFunction(const char *filename, const char *moduleName, const char *functionName, int nu, const double u[], int ny, double y[]) {
 
 	UNUSED(moduleName)
-	UNUSED(pythonHome)
 
 	if (strcmp(functionName, "external_library_function")) {
 		return "Argument functionName must be \"external_library_function\".";
@@ -62,10 +61,9 @@ class ExternalLibraryObject {
 
 };
 
-void* createExternalObject(const char *filename, const char *moduleName, const char *className, const char *pythonHome, const ModelicaUtilityFunctions_t *callbacks) {
+void* createExternalObject(const char *filename, const char *moduleName, const char *className, const ModelicaUtilityFunctions_t *callbacks) {
 
 	UNUSED(moduleName)
-	UNUSED(pythonHome)
 
 	s_callbacks = *callbacks;
 

C/src/ExternalLibraryPython.c

@@ -16,25 +16,7 @@
 
 #define PYTHON_MODULE "external_library"
 
-const char* externalFunction(const char* filename, const char* moduleName, const char* functionName, const char* pythonHome, int nu, const double u[], int ny, double y[]) {
-
-#ifdef _WIN32
-	DWORD dwAttrib = GetFileAttributesA(pythonHome);
-
-	int valid = dwAttrib != INVALID_FILE_ATTRIBUTES;
-	int isdir = dwAttrib & FILE_ATTRIBUTE_DIRECTORY;
-
-	if (!pythonHome || !valid || !isdir) {
-		return "Argument pythonHome must be a valid directory.";
-	}
-
-	BOOL res = SetDllDirectoryA(pythonHome);
-#endif
-
-	size_t size;
-	const wchar_t *python_home_w = Py_DecodeLocale(pythonHome, &size);
-
-	Py_SetPythonHome(python_home_w);
+const char* externalFunction(const char* filename, const char* moduleName, const char* functionName, int nu, const double u[], int ny, double y[]) {
 
 	Py_Initialize();
 
@@ -92,32 +74,13 @@ typedef struct {
 } PythonObjects;
 
 
-void* createExternalObject(const char* filename, const char* moduleName, const char* className, const char* pythonHome, const ModelicaUtilityFunctions_t* callbacks) {
+void* createExternalObject(const char* filename, const char* moduleName, const char* className, const ModelicaUtilityFunctions_t* callbacks) {
 
 	if (!filename) {
 		callbacks->ModelicaError("Argument filename must not be NULL.");
 		return NULL;
 	}
 
-#ifdef _WIN32
-	DWORD dwAttrib = GetFileAttributesA(pythonHome);
-
-	int valid = dwAttrib != INVALID_FILE_ATTRIBUTES;
-	int isdir = dwAttrib & FILE_ATTRIBUTE_DIRECTORY;
-
-	if (!pythonHome || !valid || !isdir) {
-		callbacks->ModelicaError("Argument pythonHome must be a valid directory.");
-		return NULL;
-	}
-
-	BOOL res = SetDllDirectoryA(pythonHome);
-#endif
-
-	size_t size;
-	const wchar_t *python_home_w = Py_DecodeLocale(pythonHome, &size);
-
-	Py_SetPythonHome(python_home_w);
-
 	Py_Initialize();
 
 	PythonObjects *o = malloc(sizeof(PythonObjects));

C/tests/ExternalLibrary_test.cpp

@@ -78,7 +78,7 @@ TEST_CASE("External functions can be loaded and called", "[ExternalLibrary]") {
 		double u[] = { 1, 2 };
 		double y[] = { 0, 0 };
 
-		auto message = fp_externalFunction(DATA_FILE, MODULE_NAME, FUNCTION_NAME, PYTHON_HOME, 2, u, 2, y);
+		auto message = fp_externalFunction(DATA_FILE, MODULE_NAME, FUNCTION_NAME, 2, u, 2, y);
 
 		CHECK_THAT(message, Equals(""));
 		CHECK(y[0] == 4);
@@ -89,7 +89,7 @@ TEST_CASE("External functions can be loaded and called", "[ExternalLibrary]") {
 
 		auto fp_createExternalObject = get<createExternalObject>(l, "createExternalObject");
 
-		fp_createExternalObject(nullptr, nullptr, nullptr, nullptr, &callbacks);
+		fp_createExternalObject(nullptr, nullptr, nullptr, &callbacks);
 
 		CHECK_THAT(s_errorMessage, Equals("Argument filename must not be NULL."));
 	}
@@ -103,7 +103,7 @@ TEST_CASE("External functions can be loaded and called", "[ExternalLibrary]") {
 		double u[] = { 1, 2 };
 		double y[] = { 0, 0 };
 
-		void *externalObject = fp_createExternalObject(DATA_FILE, MODULE_NAME, CLASS_NAME, PYTHON_HOME, &callbacks);
+		void *externalObject = fp_createExternalObject(DATA_FILE, MODULE_NAME, CLASS_NAME, &callbacks);
 
 		REQUIRE(externalObject);
 

ExternalLibrary/ExternalLibraryFunctionExample.mo

@@ -6,7 +6,6 @@ model ExternalLibraryFunctionExample
       Modelica.Utilities.Files.loadResource("modelica://ExternalLibrary/Resources/Data/data.txt"),
       "external_library",
       "external_library_function",
-      Modelica.Utilities.System.getEnvironmentVariable("PYTHONHOME"),
       {1,2});
 
 end ExternalLibraryFunctionExample;

ExternalLibrary/ExternalLibraryObject.mo

@@ -5,10 +5,9 @@ model ExternalLibraryObject
   parameter String filename "Filename of the data file";
   parameter String moduleName "Python module name of the external object";
   parameter String className "Class name of the external object";
-  parameter String pythonHome "Path to the Python environment";
 
   ExternalLibrary.Internal.ExternalLibraryObject externalObject=
-      ExternalLibrary.Internal.ExternalLibraryObject(filename, moduleName, className, pythonHome);
+      ExternalLibrary.Internal.ExternalLibraryObject(filename, moduleName, className);
 
 protected
   function evaluate

ExternalLibrary/ExternalLibraryObjectExample.mo

@@ -10,15 +10,14 @@ model ExternalLibraryObjectExample
     nout=2,
     filename=Modelica.Utilities.Files.loadResource(
         "modelica://ExternalLibrary/Resources/Data/data.txt"),
-                                      moduleName="external_library", className="ExternalLibraryObject",
-    pythonHome=Modelica.Utilities.System.getEnvironmentVariable("PYTHONHOME"))
+        moduleName="external_library", className="ExternalLibraryObject")
     annotation (Placement(transformation(extent={{-10,-10},{10,10}})));
 equation
   connect(sine.y, libraryObject.u[1]) annotation (Line(points={{-39,28},{-26,28},
-          {-26,-1},{-12,-1}},
+          {-26,-0.5},{-12,-0.5}},
                             color={0,0,127}));
-  connect(sine1.y, libraryObject.u[2]) annotation (Line(points={{-39,-30},{-26,
-          -30},{-26,1},{-12,1}}, color={0,0,127}));
+  connect(sine1.y, libraryObject.u[2]) annotation (Line(points={{-39,-30},{-26,-30},
+          {-26,0.5},{-12,0.5}},  color={0,0,127}));
   annotation (
     Icon(coordinateSystem(preserveAspectRatio=false)),
     Diagram(coordinateSystem(preserveAspectRatio=false, extent={{-100,-100},{

ExternalLibrary/Internal.mo

@@ -37,14 +37,12 @@ package Internal
       input String filename;
       input String moduleName;
       input String className;
-      input String pythonHome;
       input ExternalLibrary.Internal.ModelicaUtilityFunctions callbacks=ExternalLibrary.Internal.ModelicaUtilityFunctions();
       output ExternalLibraryObject externalObject;
     external"C" externalObject = createExternalObject(
           filename,
           moduleName,
           className,
-          pythonHome,
           callbacks)
         annotation (Library="ExternalLibrary");
     end constructor;
@@ -68,7 +66,6 @@ package Internal
     input String filename;
     input String moduleName;
     input String functionName;
-    input String pythonHome;
     input Integer nu;
     input Real[nu] u;
     input Integer ny;
@@ -78,7 +75,6 @@ package Internal
       filename,
       moduleName,
       functionName,
-      pythonHome,
       size(u, 1),
       u,
       size(y, 1),

ExternalLibrary/externalLibraryFunction.mo

@@ -3,7 +3,6 @@ function externalLibraryFunction
   input String filename;
   input String moduleName;
   input String functionName;
-  input String pythonHome;
   input Real[2] u={1,2};
   output Real[2] y;
 protected
@@ -13,7 +12,6 @@ algorithm
     filename,
     moduleName,
     functionName,
-    pythonHome,
     size(u, 1),
     u,
     size(y, 1));

LICENSE.txt

@@ -1,6 +1,6 @@
 BSD 2-Clause License
 
-Copyright (c) 2023, Dassault Systèmes. All rights reserved.
+Copyright (c) 2024, Dassault Systèmes. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

README.md

@@ -46,23 +46,34 @@ To run the tests, right click on the `ExternalLibraryTest` project, select `Set
 
 To build a shared library that calls Python follow the steps above, but after you pressed `Configure`, select `EXTERNAL_LANGUAGE=Python` and set `PYTHON_HOME=C:/Anaconda3` (assuming that you installed Anaconda Python 3.7 in `C:/Anaconda3`).
 
-To install the Python library in development mode run `pip install -e Python` in the root of the repository. This will allow you edit the Python code without reinstalling the library.
+To install the Python library in development mode run `pip install -e Python` in the root of the repository.
+This will allow you edit the Python code without reinstalling the library.
 
-Run `ExternalLibraryTest` in Visual Studio to check if everything is set up correctly.
+In order use load the Python binaries and their dependencies two environment variables need to be for the process loading the `ExternalLibrary.dll`.
+
+`PYTHONHOME` needs to point to the folder that contains the Python executable.
+It can retrieved by running `which python`.
+
+`PATH` needs to contain all folders that contain Python binaries and dependencies.
+For Conda environments these can be retrived by running `set PATH` inside a Conda prompt.
+
+On the `ExternalLibraryTest` project in Visual Studio right-click and selct `Properties > Configuration Properties > Debugging`.
+In `Environment` set the two environment variables and run the project to check if everything is set up correctly.
 
 ## Modelica library
 
-The Modelica library is the same for both the C++ and the Python backend. It contains a Modelica function `libraryFunction` that can be used e.g. to load data at the beginning of a simulation and an ExternalObject `LibraryObject` to connect to external code during the simulation (e.g. to inter- or extrapolate using special algorithms).
+The Modelica library is the same for both the C++ and the Python backend.
+It contains a Modelica function `libraryFunction` that can be used e.g. to load data at the beginning of a simulation and an ExternalObject `LibraryObject` to connect to external code during the simulation (e.g. to inter- or extrapolate using special algorithms).
 
 ![Modelica library](ExternalLibrary/Resources/Images/ExternalLibrary.png)
 
-After loading the `ExternalLibrary` package in Dymola, go to `Commands` and run `Advanced.CompileWith64=2` to compile 64-bit binaries and `Modelica.Utilities.System.setEnvironmentVariable("PYTHONHOME", "C:/Anaconda3")`, so the shared library knows where to search for the Python installation.
+After loading the `ExternalLibrary` package in Dymola, go to `Commands` and run `Advanced.CompileWith64=2` to compile 64-bit binaries and `Modelica.Utilities.System.setEnvironmentVariable("PYTHONHOME", ...)`  and `Modelica.Utilities.System.setEnvironmentVariable("PATH", ...)` (see previous section), so the shared library knows where to search for the Python installation and dependencies.
 
-To run the function with the default parameters, right click `libraryFunction` and select `Run Function...` and then `Execute`.
+To run the function with the default parameters, right click `externalLibraryFunction` and select `Run Function...` and then `Execute`.
 
-The `LibraryObjectExample` demonstrates the use of the external object.
+The `ExternalLibraryFunctionExample` and `ExternalLibraryObjectExample` demonstrates the use of the external function and object respectively.
 
 ## License
 
-Copyright © 2023 Dassault Systèmes.
+Copyright © 2024 Dassault Systèmes.
 The code is released under the [2-Clause BSD license](LICENSE.txt).