Method PythonEngine

python/engine/PythonEngine.cpp:85–134

}

PythonEngine::PythonEngine(int argc, char* argv[]) : ScriptEngine(argc, argv), program(Py_DecodeLocale(pythonProgramName, nullptr)) {
  // TODO: modernize and use PyConfig (new in 3.8): https://docs.python.org/3/c-api/init_config.html

  // this frozen flag tells Python that the package and library have been frozen for embedding, so it shouldn't warn about missing prefixes
  Py_FrozenFlag = 1;

  // Path to the E+ shipped standard library
  auto pathToPythonPackages = getEnergyPlusDirectory() / "python_lib";

  // The PYTHONPATH / PYTHONHOME should be set before initializing Python
  // If this Py_SetPath is called before Py_Initialize, then Py_GetPath won't attempt to compute a default search path
  // The default search path is affected by the Py_SetPythonHome
  // * if the user passed --python_home, we use that as the Python Home, and do not use Py_SetPath. But later we add the E+ standard_lib anyways
  //   so it takes precedence (to limit incompatibility issues...)
  // * If the user didn't pass it, we use Py_SetPath set to the E+ standard_lib

  std::vector<std::string> args(argv, std::next(argv, static_cast<std::ptrdiff_t>(argc)));
  bool pythonHomePassed = false;
  auto it = std::find(args.cbegin(), args.cend(), "--python_home");
  if (it != args.cend()) {
    openstudio::path pythonHomeDir(*std::next(it));
    wchar_t* h = Py_DecodeLocale(pythonHomeDir.make_preferred().string().c_str(), nullptr);
    Py_SetPythonHome(h);
    pythonHomePassed = true;
  } else {
    wchar_t* a = Py_DecodeLocale(pathToPythonPackages.make_preferred().string().c_str(), nullptr);
    Py_SetPath(a);
  }

  Py_SetProgramName(program);  // optional but recommended

  Py_Initialize();

  if (pythonHomePassed) {
    addToPythonPath(pathToPythonPackages);
  }
#if defined(__APPLE__) || defined(__linux___) || defined(__unix__)
  addToPythonPath(pathToPythonPackages / "lib-dynload");
#endif

  PyObject* m = PyImport_AddModule("__main__");
  if (m == nullptr) {
    throw std::runtime_error("Unable to add module __main__ for python script execution");
  }
  m_globalDict = PyModule_GetDict(m);

  //PyRun_SimpleString("from time import time,ctime\n"
  //                   "print('Today is', ctime(time()))\n");
  importOpenStudio();
}

PythonEngine::~PythonEngine() {
  if (Py_FinalizeEx() < 0) {