From a648b12e31822b023501bb60e12403b6ba54095d Mon Sep 17 00:00:00 2001
From: Steve0x2a <stevesough@gmail.com>
Date: Tue, 17 Aug 2021 13:59:39 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A00129=E6=B1=82=E6=A0=B9?=
 =?UTF-8?q?=E5=88=B0=E5=8F=B6=E5=AD=90=E8=8A=82=E7=82=B9=E6=95=B0=E5=AD=97?=
 =?UTF-8?q?=E4=B9=8B=E5=92=8C=20Python3=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../0129.求根到叶子节点数字之和.md | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/problems/0129.求根到叶子节点数字之和.md b/problems/0129.求根到叶子节点数字之和.md
index b37270e2..17642793 100644
--- a/problems/0129.求根到叶子节点数字之和.md
+++ b/problems/0129.求根到叶子节点数字之和.md
@@ -165,7 +165,32 @@ public:
 Java： 
 
 Python：
+```python3
+class Solution:
+    def sumNumbers(self, root: TreeNode) -> int:
+        res = 0
+        path = []
+        def backtrace(root):
+            nonlocal res
+            if not root: return # 节点空则返回
+            path.append(root.val)
+            if not root.left and not root.right: # 遇到了叶子节点
+                res += get_sum(path)
+            if root.left: # 左子树不空
+                backtrace(root.left)
+            if root.right: # 右子树不空
+                backtrace(root.right)
+            path.pop()
 
+        def get_sum(arr):
+            s = 0
+            for i in range(len(arr)):
+                s = s * 10 + arr[i]
+            return s
+
+        backtrace(root)
+        return res
+```
 Go：
 
 JavaScript：