Darken screen around area

darkenScreenAroundArea.py

import wx
import time
from multiprocessing import Process, Lock
 
def darkenScreenAroundArea(lock, x, y, width, height):
    app = wx.App(False)
    screensize = wx.GetDisplaySize()
    frm = DarkFrame(lock, 0, 0, screensize[0], y) # top
    frm = DarkFrame(lock, 0, y, x, height) # left
    frm = DarkFrame(lock, (x + width), y, (screensize[0] - x + width), height) # right
    frm = DarkFrame(lock, 0, (y + height), screensize[0], (screensize[1] - y + height)) # bottom
    app.MainLoop()

class DarkFrame(wx.Frame):
    def __init__(self, lock, x, y, width, height):
        wx.Frame.__init__(self, None, title='', style=wx.NO_BORDER, size=(width,height), pos=(x,y))
        self.SetBackgroundColour('BLACK')
        self.SetTransparent(140)
        self.Show()
        self.lock = lock
        self.timer = wx.Timer(self)
        self.Bind(wx.EVT_TIMER, self.update, self.timer)
        self.timer.Start(50, wx.TIMER_CONTINUOUS)

    def update(self, event):
        if self.lock.acquire(block=False):
            self.lock.release()
            self.Close()

lock = Lock()
lock.acquire()
p = Process(target=darkenScreenAroundArea, args=(lock, 400, 200, 500, 300))
p.start()
time.sleep(5)
lock.release()
p.join()