print_exception(PyObject *f, PyObject *value)
{
    int err = 0;
    PyObject *type, *tb;
    _Py_IDENTIFIER(print_file_and_line);

    if (!PyExceptionInstance_Check(value)) {
        err = PyFile_WriteString("TypeError: print_exception(): Exception expected for value, ", f);
        err += PyFile_WriteString(Py_TYPE(value)->tp_name, f);
        err += PyFile_WriteString(" found\n", f);
        if (err)
            PyErr_Clear();
        return;
    }

    Py_INCREF(value);
    fflush(stdout);
    type = (PyObject *) Py_TYPE(value);
    tb = PyException_GetTraceback(value);
    if (tb && tb != Py_None)
        err = PyTraceBack_Print(tb, f);
    if (err == 0 &&
        _PyObject_HasAttrId(value, &PyId_print_file_and_line))
    {
        PyObject *message, *filename, *text;
        int lineno, offset;
        if (!parse_syntax_error(value, &message, &filename,
                                &lineno, &offset, &text))
            PyErr_Clear();
        else {
            PyObject *line;

            Py_DECREF(value);
            value = message;

            line = PyUnicode_FromFormat("  File \"%U\", line %d\n",
                                          filename, lineno);
            Py_DECREF(filename);
            if (line != NULL) {
                PyFile_WriteObject(line, f, Py_PRINT_RAW);
                Py_DECREF(line);
            }

            if (text != NULL) {
                print_error_text(f, offset, text);
                Py_DECREF(text);
            }

            /* Can't be bothered to check all those
               PyFile_WriteString() calls */
            if (PyErr_Occurred())
                err = -1;
        }
    }
    if (err) {
        /* Don't do anything else */
    }
    else {
        PyObject* moduleName;
        const char *className;
        _Py_IDENTIFIER(__module__);
        assert(PyExceptionClass_Check(type));
        className = PyExceptionClass_Name(type);
        if (className != NULL) {
            const char *dot = strrchr(className, '.');
            if (dot != NULL)
                className = dot+1;
        }

        moduleName = _PyObject_GetAttrId(type, &PyId___module__);
        if (moduleName == NULL || !PyUnicode_Check(moduleName))
        {
            Py_XDECREF(moduleName);
            err = PyFile_WriteString("<unknown>", f);
        }
        else {
            if (!_PyUnicode_EqualToASCIIId(moduleName, &PyId_builtins))
            {
                err = PyFile_WriteObject(moduleName, f, Py_PRINT_RAW);
                err += PyFile_WriteString(".", f);
            }
            Py_DECREF(moduleName);
        }
        if (err == 0) {
            if (className == NULL)
                      err = PyFile_WriteString("<unknown>", f);
            else
                      err = PyFile_WriteString(className, f);
        }
    }
    if (err == 0 && (value != Py_None)) {
        PyObject *s = PyObject_Str(value);
        /* only print colon if the str() of the
           object is not the empty string
        */
        if (s == NULL) {
            PyErr_Clear();
            err = -1;
            PyFile_WriteString(": <exception str() failed>", f);
        }
        else if (!PyUnicode_Check(s) ||
            PyUnicode_GetLength(s) != 0)
            err = PyFile_WriteString(": ", f);
        if (err == 0)
          err = PyFile_WriteObject(s, f, Py_PRINT_RAW);
        Py_XDECREF(s);
    }
    /* try to write a newline in any case */
    if (err < 0) {
        PyErr_Clear();
    }
    err += PyFile_WriteString("\n", f);
    Py_XDECREF(tb);
    Py_DECREF(value);
    /* If an error happened here, don't show it.
       XXX This is wrong, but too many callers rely on this behavior. */
    if (err != 0)
        PyErr_Clear();
}
Unknown