Given the root to a binary tree, implement serialize(root), which serializes the tree into a string, and deserialize(s), which deserializes the string back into the tree.

Daily_Coding_Problem_3.py

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

class Serialize_To_Deserialize:
    def serialize(self, root):
        """Encodes a tree to a single string.
        
        :type root: TreeNode
        :rtype: str
        """
        from collections import deque
        
        if root is None:
            return ""
        qu=deque()
        data=[]
        qu.appendleft(root)
        while len(qu)>0:
            node=qu.pop()
            if node is None:
                data.append("$")
                continue
            else:
                data.append(str(node.val))
                qu.appendleft(node.left)
                qu.appendleft(node.right)
        return ' '.join(data)

    def deserialize(self, data):
        """Decodes your encoded data to tree.
        
        :type data: str
        :rtype: TreeNode
        """
        from collections import deque
		
        if len(data) is 0:
            return None
        vals=iter(data.split())
        root=TreeNode(int(next(vals)))
        qu=deque()
        qu.appendleft(root)
        while len(qu)>0:
            node=qu.pop()
            left=next(vals)
            right=next(vals)
            if left is not '$':
                new_node=TreeNode(int(left))
                node.left=new_node
                qu.appendleft(new_node)
            else:
                node.left=None
            if right is not '$':
                new_node=TreeNode(int(right))
                node.right=new_node
                qu.appendleft(new_node)
            else:
                node.right=None
        return root
                
        
# std = Serialize_To_Deserialize()
# std.deserialize(std.serialize(root))