Function check_error

src/utils/python.cpp:98–142

bool is_active() { return Py_IsInitialized(); }

void check_error(bool force_error)
{
  global_interpreter_lock gil;
  if (force_error || PyErr_Occurred()) {

    // Get error information from Python session
    PyObject *type_ptr, *value_ptr, *traceback_ptr;
    PyErr_Fetch(&type_ptr, &value_ptr, &traceback_ptr);
    object type(type_ptr), value(value_ptr), traceback(traceback_ptr);

    // Construct error message
    std::ostringstream err;
    err << "detected Python error";
    if (value != nullptr) {
      object msg = PyObject_Repr(value);
      msg = PyUnicode_AsEncodedString(msg, "utf-8", "Error -");
      err << " (" << PyBytes_AS_STRING(msg.get()) << ")";
    }

    // Print Python traceback if available
    if (traceback != nullptr) {

      // Format traceback
      object module = PyImport_ImportModule("traceback");
      object func = PyObject_GetAttrString(module, "format_tb");
      object message =
        PyObject_CallMethod(module, "format_tb", "(O)", traceback.get());

      // Print traceback
      err << "\n\n"
          << "Python traceback:";
      object iter = PyObject_GetIter(message);
      for (object line = PyIter_Next(iter); line != nullptr;
           line = PyIter_Next(iter)) {
        const char* line_ = PyUnicode_AsUTF8(line);
        err << "\n" << (line_ ? line_ : "");
      }
    }

    // Clean up and throw exception
    PyErr_Restore(type.release(), value.release(), traceback.release());
    PyErr_Clear();
    LBANN_ERROR(err.str());
  }
}

// ---------------------------------------------
// global_interpreter_lock class