Pywin32 opens the specified window

def open_app():
    try:
        win32api.ShellExecute(0, 'open', self.app_path, '', '', 1)
    except:
        print(f'Program can not be opened...')


def get_windows(windowsname, filename):
	#  Get window handle 
	handle = win32gui.FindWindow(None, os.path.basename(windowsname).split('.')[0])
	#  Judge whether the application is opened , If it doesn't open , Not open handle by 0
	if handle == 0:
		print(' Program not open '.center(50, '='))
		open_app(windowsname)
		time.sleep(2)
		# app  After opening , Back to the handle assignment 
		handle = win32gui.FindWindow(None, os.path.basename(windowsname).split('.')[0])

	#  When applying minimize , Use this instruction to maximize the application again --> This statement is very important 
	win32gui.ShowWindow(handle, win32con.SW_MAXIMIZE)
	##  Put the window on the front desk , And activate the window （ Windows cannot be minimized ）
	win32gui.SetForegroundWindow(handle)
	time.sleep(1)
	#  Get the window DC
	hdDC = win32gui.GetWindowDC(handle)
	#  Create a... Based on the handle DC
	newhdDC = win32ui.CreateDCFromHandle(hdDC)
	#  Create a compatible device memory DC
	saveDC = newhdDC.CreateCompatibleDC()
	#  establish bitmap Save the picture 
	saveBitmap = win32ui.CreateBitmap()

	#  Get window location information 
	left, top, right, bottom = win32gui.GetWindowRect(handle)
	#  Window length and width 
	width = right - left
	height = bottom - top
	# bitmap initialization 
	saveBitmap.CreateCompatibleBitmap(newhdDC, width, height)
	saveDC.SelectObject(saveBitmap)
	saveDC.BitBlt((0, 0), (width, height), newhdDC, (0, 0), win32con.SRCCOPY)
	saveBitmap.SaveBitmapFile(saveDC, filename)


get_windows(r"C:\Users\Administrator\Desktop\PyWin32.chm", " Screenshot .png")

explain , Refer to the code of other big men on the network , When writing an article , No connection found , Please forgive me , Changes have been made to the code , It mainly solves the problem of calling the window , The program doesn't exist , Or the program is currently minimized , Return to the desktop from the minimized state , For reference only