How to clear the screen of glitched rectangles?

[user294869]

I'm coding a program that captures a section of the screen as an image by drawing a rectangle with cursor, yet the process creates glitched rectangles. Is there a way to refresh the screen or maybe a completely different code that works? The dc.Clear() doesn't seem to clear the screen.

import wx 
import win32gui

app = wx.PySimpleApp() 
dc = wx.ScreenDC() 

dc.StartDrawingOnTop(None) 
dc.SetPen(wx.Pen('red', 2)) 
dc.SetBrush(wx.TRANSPARENT_BRUSH) 

int_x = win32gui.GetCursorPos()[0]
int_y = win32gui.GetCursorPos()[1]


while 1:
    dc.DrawRectangle(int_x,int_y,win32gui.GetCursorPos()[0]-int_x,win32gui.GetCursorPos()[1]-int_y)
    dc.Clear()