Kth largest in BST created by vetional - https://repl.it/MSfG/2

main.py

class node:
  def __init__(self, data):
    print "creating node: ",  data
    self.data = data
    self.left = None
    self.right = None
  
  def insert(self, data):
    if self.data > data:
      print "go left from:", self.data, " for ", data
      if self.left is None:
        self.left = node(data)
      else:
        self.left.insert(data)
    else:
      print "go right from:", self.data, " for ", data
      if self.right is None:
        self.right = node(data)
      else:
        self.right.insert(data)
    
    
  def preorder(self):
    
    if self.data is not None:
      print self.data
      
    if self.left is not None:
      self.left.inorder()
    
    if self.right is not None:
      self.right.inorder()
  
  def inorder(self):
    
    if self.left is not None:
      for key in self.left.inorder():
        yield key
    
    if self.data is not None:
      yield self.data
    
    if self.right is not None:
      for key in  self.right.inorder():
        yield key
        
class BST:
  def __init__(self, data):
    self.root = node(data)
    self.size = 1
    
  def insert(self, data):
    if self.root is None:
      self.root = node(data)
    else:
      self.root.insert(data)
    self.size += 1
    
  def inorder(self):
    print "printing tree rooted at: " , self.root.data
    if self.root:
      self.root.inorder()
  
  def preorder(self):
    print "printing preorder tree rooted at: " , self.root.data
    if self.root:
      self.root.preorder()

  def k_largest(self, k):
    for i,x in enumerate(self.root.inorder()):
      if i == (self.size - k):
        return x
    return -1
bst = BST(10)
bst.insert(5)
bst.insert(15)
bst.insert(12)
bst.insert(16)
bst.insert(6)

k = 2
print bst.k_largest(k)