import subprocess
IS_WIN32 = 'win32' in str(sys.platform).lower()
def subprocess_call(*args, **kwargs):
  #also works for Popen. 
  #It creates a new *hidden* window, 
  #so it will work in frozen apps (.exe).
  if IS_WIN32:
    startupinfo = subprocess.STARTUPINFO()
    startupinfo.dwFlags = subprocess.CREATE_NEW_CONSOLE | subprocess.STARTF_USESHOWWINDOW
    startupinfo.wShowWindow = subprocess.SW_HIDE
    kwargs['startupinfo'] = startupinfo
  retcode = subprocess.call(*args, **kwargs)
  return retcode