Heap Sort in Python

# Heap sort method
def heapSort(arr):
   size = len(arr)

   for i in range(size / 2 - 1, 0, -1):
       heapify(arr, size, i)
   
   i = size - 1
   while i >= 1:
       swap(arr, 0, i)
       heapify(arr, i, 0)
       i -= 1

# Converts the remaining array to a max-heap binary tree  
def heapify(arr, size, i):
   largest = i
   leftLeaf = 2 * i + 1
   rightLeaf = 2 * i + 2

   if leftLeaf < size and arr[leftLeaf] > arr[largest]:
       largest = leftLeaf
   if rightLeaf < size and arr[rightLeaf] > arr[largest]:
       largest = rightLeaf
   
   if largest != i:
       swap(arr, i, largest)
       heapify(arr, size, largest)

# Helper method to swap in place
def swap(arr, a, b):
   tmp = arr[a]
   arr[a] = arr[b]
   arr[b] = tmp