def sort(arr):
	return arr;

if __name__ == '__main__':
	unsorted = list(reversed(range(1000)));
	print sort(unsorted);
def sort(arr, length):
	if length == 1:
		return
	return (arr, length)

if __name__ == '__main__':
	unsorted = list(reversed(range(1000)))
	initial_len = len(unsorted)
	print sort(unsorted, initial_len)
Add length parameter to sort and remove semicolons