class _GetCh:
  def __init__(self):
    try:
      self.impl = _GetChWindows()
    except ImportError:
      try:
        self.impl = _GetChMacCarbon()
      except ImportError:
        self.impl = _GetChUnix()
  def __call__(self):
    return self.impl()

class _GetChWindows:
  def __init__(self):
    import msvcrt
  def __call__(self):
    import msvcrt
    if msvcrt.kbhit():
      while msvcrt.kbhit():
        ch = msvcrt.getch()
      while ch in b'\x00\xe0':
        msvcrt.getch()
        ch = msvcrt.getch()
      return ord( ch.decode() )
    else:
      return -1

class _GetChMacCarbon:
  def __init__(self):
    import Carbon
    Carbon.Evt
  def __call__(self):
    import Carbon
    if Carbon.Evt.EventAvail(0x0008)[0]==0: # 0x0008 is the keyDownMask
      return ""
    else:
      (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
      return msg & 0x000000FF

class _GetChUnix:
  def __init__(self):
    import tty, sys, termios # import termios now or else you'll get the Unix
                             # version on the Mac
  def __call__(self):
    import sys, tty, termios
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    try:
      tty.setraw(sys.stdin.fileno())
      ch = sys.stdin.read(1)
    finally:
      termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
    return ord(ch)

if __name__ == '__main__':

    InKey = _GetCh()

    print( "Press Ctrl-C to exit" )

    c = InKey()
    while c != 3:
      if c >= 0:
        print( c )
      c = InKey()