Win32 CreateWindow example in python

winapp.py

# Adapted for Python 3.6 + 64-bit Windows

from ctypes import *
from ctypes.wintypes import *

WNDPROCTYPE = WINFUNCTYPE(c_int, HWND, c_uint, WPARAM, LPARAM)

WS_EX_APPWINDOW = 0x40000
WS_OVERLAPPEDWINDOW = 0xcf0000
WS_CAPTION = 0xc00000

SW_SHOWNORMAL = 1
SW_SHOW = 5

CS_HREDRAW = 2
CS_VREDRAW = 1

CW_USEDEFAULT = 0x80000000

WM_DESTROY = 2

WHITE_BRUSH = 0


class WNDCLASSEX(Structure):
    _fields_ = [("cbSize", c_uint),
                ("style", c_uint),
                ("lpfnWndProc", WNDPROCTYPE),
                ("cbClsExtra", c_int),
                ("cbWndExtra", c_int),
                ("hInstance", HANDLE),
                ("hIcon", HANDLE),
                ("hCursor", HANDLE),
                ("hBrush", HANDLE),
                ("lpszMenuName", LPCWSTR),
                ("lpszClassName", LPCWSTR),
                ("hIconSm", HANDLE)]

user32 = ctypes.WinDLL('user32',use_last_error=True)
user32.DefWindowProcW.argtypes =[ HWND, c_uint, WPARAM, LPARAM]

def PyWndProcedure(hWnd, Msg, wParam, lParam):
    if Msg == WM_DESTROY:
        user32.PostQuitMessage(0)
        return 0
    return user32.DefWindowProcW(hWnd, Msg, wParam, lParam)
  


def main():
    WndProc = WNDPROCTYPE(PyWndProcedure)
    hInst = windll.kernel32.GetModuleHandleW(0)
    wclassName = u'My Python Win32 Class'
    wname = u'My test window'
    
    wndClass = WNDCLASSEX()
    wndClass.cbSize = sizeof(WNDCLASSEX)
    wndClass.style = CS_HREDRAW | CS_VREDRAW
    wndClass.lpfnWndProc = WndProc
    wndClass.cbClsExtra = 0
    wndClass.cbWndExtra = 0
    wndClass.hInstance = hInst
    wndClass.hIcon = 0
    wndClass.hCursor = 0
    wndClass.hBrush = windll.gdi32.GetStockObject(WHITE_BRUSH)
    wndClass.lpszMenuName = 0
    wndClass.lpszClassName = wclassName
    wndClass.hIconSm = 0
    
    regRes = windll.user32.RegisterClassExW(byref(wndClass))
    
    hWnd = windll.user32.CreateWindowExW(
    0,wclassName,wname,
    WS_OVERLAPPEDWINDOW | WS_CAPTION,
    CW_USEDEFAULT, CW_USEDEFAULT,
    300,300,0,0,hInst,0)
    
    if not hWnd:
        print('Failed to create window')
        exit(0)
    print('ShowWindow', windll.user32.ShowWindow(hWnd, SW_SHOW))
    print('UpdateWindow', windll.user32.UpdateWindow(hWnd))

    msg = MSG()
    lpmsg = pointer(msg)

    print('Entering message loop')
    while windll.user32.GetMessageA(lpmsg, 0, 0, 0) != 0:
        windll.user32.TranslateMessage(lpmsg)
        windll.user32.DispatchMessageA(lpmsg)

    print('done.')
    
    
if __name__ == "__main__":
    print ("Win32 Application in python")
    main()