Updated heap.py

heap.py

 # i. Also, n is the size of a heap and arr is array.
 
 def heapify(lista, n, i):
-		# largest is root for now
+        # largest is root for now
 		largest = i
 
 		# left child of root
-		left = 2 * i + 1
+		l = 2 * i + 1
 
 		# right child of root
-		right = 2 * i + 2
+		r = 2 * i + 2
 
 		# Checks if root has a left child and is greater
 		# than root