61.序列化二叉树(python)

 1 class Solution:
 2     def Serialize(self, root):
 3         # write code here 
 4         retList = []
 5         def preOrder(root):
 6             if root == None:
 7                 retList.append("#")
 8                 return 
 9             retList.append(str(root.val))
10             preOrder(root.left)
11             preOrder(root.right)
12         preOrder(root)
13         return ‘ ‘.join(retList)
14     def Deserialize(self, s):
15         # write code here
16         retList = s.split()
17         def dePreOrder():
18             if retList == []:
19                 return None
20             rootVal = retList[0]
21             del retList[0]
22             if rootVal == "#":
23                 return None
24             node = TreeNode(int(rootVal))
25             leftNode = dePreOrder()
26             rightNode = dePreOrder()
27             node.left = leftNode
28             node.right = rightNode
29             return node
30         pRoot = dePreOrder()
31         return pRoot