python - Building a Tree with inorder and preorder traversal in Python3.x -

i trying build tree using preorder , inorder traversals (list of ints). here have far:

def build(preorder, inorder, heap): # builds tree inorder , preorder traversal     if len(preorder) == 0:         return none     root = preorder[0] # root first item in preorder     k = root     left_count = inorder[(k-1)] # number of items in left sub-tree     left_inorder = inorder[0:left_count]     left_preorder = preorder[1:1+left_count]     right_inorder = inorder[1+left_count:]     right_preorder = preorder[1+left_count:]     return [root, build(left_preorder, left_inorder), build(right_preorder, right_inorder)] 

i believe algorithm correct, although wrong.

my question - @ point insert items tree? have class written handle this, i'm not sure insert call, function operate recursively. suggestions how should insert nodes tree appreciated.

class heap:      def __init__(self,the_heap):          self.heap = the_heap      def getchildren(self,value):          n = self.heap.index(value)          return self.heap[2*n+1],self.heap[2*n+2] # think ...      def getparent(self,value):          n = self.heap.index(value)          if n == 0: return none          return self.heap[math.floor(n-1/2.0) ] # think ...      def traverse(self):          #do traversal here visit each node in order want          pass  the_heap = heap(range(100))  print the_heap.getchildren(2) print the_heap.getparent(6) 

something that?