Binary Tree Size function in Python -

i have written couple of functions calculate size of binary tree. first 1 (function 1) works fine , declared outside class, not member function of class. second 1 member function of class giving me weird results. confused! appreciated.

function 1     def size(root):         if root none:             return 0         else:             return size(root.left)+ 1+ size(root.right)   function 2     def size(self):         if self.left none or self.right none:               return 0         else:               return self.left.size()+1+self.right.size() 

if self.left none or self.right none: 

if 1 of them none, return 0

you need @ least size of right + 1 if left none

i think need :

leftsize = self.left.size() if self.left else 0 rightsize = self.right.size() if self.right else 0 return leftsize + 1 + rightsize 

i havent tried it.