Function SetupPythonPrefix

Utilities/PythonInterpreter/vtkPythonInterpreter.cxx:281–305

* Since vtkPythonInterpreter is often used outside CPython executable, e.g. * vtkpython, the default logic to locate Python standard libraries used by * Python (which depends on the executable path) may fail or pickup incorrect * Python libs. This methods address the issue by setting program name to help * guide Python's default prefix/exec_prefix searching logic. */

 * guide Python's default prefix/exec_prefix searching logic.
 */
void SetupPythonPrefix(bool isolated)
{
  using systools = vtksys::SystemTools;

  // Check if we're using an isolated Python.
  if (isolated)
  {
    VTKPY_DEBUG_MESSAGE("Isolated Python detected; skipping setting up of program path.");
    return;
  }

  std::string pythonlib = vtkGetLibraryPathForSymbol(Py_InitializeEx);
  if (pythonlib.empty())
  {
    VTKPY_DEBUG_MESSAGE("static Python build or `Py_InitializeEx` library couldn't be found. "
                        "Set `PYTHONHOME` if Python standard library fails to load.");
    return;
  }

  const std::string newprogramname =
    systools::GetFilenamePath(pythonlib) + VTK_PATH_SEPARATOR "vtkpython";
  VTKPY_DEBUG_MESSAGE("calling vtkPythonInterpreter::SetProgramName("
    << newprogramname << ") to aid in setup of Python prefix.");
  vtkPythonInterpreter::SetProgramName(newprogramname.c_str());
}

#ifdef vtkPythonInterpreter_USE_DIRECTORY_COOKIE
PyObject* DLLDirectoryCookie = nullptr;