There is an example in the ctypes python3 documentation for producing a native Windows MessageBoxA 

https://docs.python.org/3.3/library/ctypes.html#ctypes.PYFUNCTYPE

Try as I might, I cannot get this example to run under python 3 (it is in the python3 documentation) - it always produces an error

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ctypes.ArgumentError: argument 2: <class 'TypeError'>: wrong type

I apologise for not attaching a fix, I have tried and cannot find one.