TreeTraversal.py

'''
preorder, inorder,postorder traversal for the binary tree
'''
class Node(object):
 '''
 TreeNode
 Args: data, left child, right child
 '''
 def __init__(self,data=None,left=None,right=None):
 self.data = data
 self.left = left
 self.right = right

class BinaryTree(object):
 def __init__(self):
 self.root = None
 def PreOrder(self,node):
 if node is None:
 return
 self.PreOrder(node.left)
 self.PreOrder(node.right)
 print node.data
 def InOrder(self,node):
 if node is None:
 return
 self.PreOrder(node.left)
 print node.data
 self.PreOrder(node.right)
 def PostOrder(self,node):
 if node is None:
 return
 print node.data
 self.PostOrder(node.left)
 self.PostOrder(node.right)

'''
 1
 2 4
3 5 6 
'''
c = Node(3)
d = Node(5)
e = Node(6)
a = Node(2,c)
b = Node(4,d,e)
root = Node(1,a,b)
tree = BinaryTree()
tree.PreOrder(b)