code: def get_dpi(raise_error=True):
      
      try:
          user32.SetProcessDPIAware()
      except AttributeError:
          pass  # not present on XP
      dc = user32.GetDC(0)
      h_size = gdi32.GetDeviceCaps(dc, HORZSIZE)
      v_size = gdi32.GetDeviceCaps(dc, VERTSIZE)
      h_res = gdi32.GetDeviceCaps(dc, HORZRES)
      v_res = gdi32.GetDeviceCaps(dc, VERTRES)
      user32.ReleaseDC(None, dc)
      return (h_res/float(h_size) + v_res/float(v_size)) * 0.5 * 25.4
docs: Get screen DPI from the OS
  
      Parameters
      ----------
      raise_error : bool
          If True, raise an error if DPI could not be determined.
  
      Returns
      -------
      dpi : float
          Dots per inch of the primary screen.