Forming BST from user , using inorder and preorder transversals

I am trying to build a binary search tree using following function:
I input a preorder and inorder list but in the final input I don’t get the desired tree.
Please help!

  def buildTree(preorder, inorder):
        if inorder:
            root = Node(preorder.pop(0))
            index = inorder.index(root.data)
            root.l_child = buildTree(preorder,inorder[:index])
            root.r_child = buildTree(preorder,inorder[index:])
            return root

>Solution :

I think there is some indexing issues.Try this

  def buildTree(preorder, inorder):
        if inorder:
            root = Node(preorder.pop(0))
            index = inorder.index(root.data)
            root.l_child = buildTree(preorder,inorder[:index])
            root.r_child = buildTree(preorder,inorder[index+1:])
            return root