Why qt_blurImage dosen't exist in PyQt5.QWidgets

[haiw2sm]

The following code is from QT source code, but i count't use the function qt_blurImage from the PyQt5.QWidgets.

QT_BEGIN_NAMESPACE
  extern Q_WIDGETS_EXPORT void qt_blurImage(QPainter *p, &blurImage, qreal radius, bool quality, bool alphaOnly, int transposed = 0);
QT_END_NAMESPACE

I wanna ask how to use that? I had tried load the function from the QWidgets dll, but it occurred some problems by using the ctype.
The python code:

import ctypes
dll = ctypes.CDLL('QWidgets.dll');

The Error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\xxx\lib\ctypes\__init__.py", line 374, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: [WinError 193] %1 不是有效的 Win32 应用程序。

Are there some any other ways? Please help me solve it.