剑指offer二叉树中和为某一值的路径python

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
    def __init__(self):
        self.onePath =[]
        self.allPath = []
    # 返回二维列表，内部每个列表表示找到的路径
    def FindPath(self, root, expectNumber):
        # write code here
        if not root:
            return self.allPath
        self.onePath.append(root.val)
        expectNumber -= root.val
        if not root.left and not root.right and expectNumber == 0:
            self.allPath.append(self.onePath[:])
        elif expectNumber > 0:
            self.FindPath(root.left,expectNumber)
            self.FindPath(root.right,expectNumber)
        self.onePath.pop()
         
        return self.allPath