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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def port_type(arg):
 	"""An argparse type representing a tcp or udp port number."""

	error_msg = "{0} is not a valid port".format(repr(arg))
	try:
		arg = ast.literal_eval(arg)
	except ValueError:
		raise argparse.ArgumentTypeError(error_msg)
	if arg < 0 or arg > 65535:
		raise argparse.ArgumentTypeError(error_msg)
	return arg