wtf.py

from collections import deque
# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Codec:

    def serialize(self, root):
        """Encodes a tree to a single string.
        
        :type root: TreeNode
        :rtype: str
        """
        nodes = deque([])
        node_string = ""
        nodes.append(root)
        while nodes:
            currNode = nodes.popleft()
            if currNode:
                node_string += str(currNode.val)
                node_string += ','
                nodes.append(currNode.left)
                nodes.append(currNode.right)
            else:
                node_string += str(None)
                node_string += ','
        
        print ("Done")
        return node_string[:-1]
        

    def deserialize(self, data):
        """Decodes your encoded data to tree.
        
        :type data: str
        :rtype: TreeNode
        """
        node_list = data.split(',')
        if not node_list:
            return None
        
        if node_list[0] == "None":
            return None
            
        n = 0
        count = 0
        root = TreeNode(int(node_list[0]))
        nodes = deque([])
        nodes.append(root)
        while nodes:
            curr_node = nodes.popleft()
            if curr_node is None:
                n += 1
                continue
            
            left = 2*n + 1
            if left < len(node_list):
                if node_list[left] != "None":
                    left_node = TreeNode(int(node_list[left]))
                    curr_node.left = left_node
                    nodes.append(left_node)
                else:
                    curr_node.left = None
                    nodes.append(None)
            
            right = 2*n + 2
            if left < len(node_list):
                if node_list[right] != "None":
                    right_node = TreeNode(int(node_list[right]))
                    curr_node.right = right_node
                    nodes.append(right_node)
                else:
                    curr_node.right = None
                    nodes.append(None)
            
            n += 1
            
        return root