Heapify method which can be used in heap sort

heapify.py

#max heap construction
def heapify(items,idx):
	left = leftChild(idx)
	right = rightChild(idx)
	largest = -1
	if(left < len(items) and items[left] > items[idx]):
		largest = left
	else:
		largest = idx

	if(right < len(items) and items[right] > items[largest]):
		largest = right

	if(largest != idx):
		temp = items[idx]
		items[idx] = items[largest]
		items[largest] = temp
		heapify(items,largest)