From 2bd13ddc1a0594b039710e4713d796232f039068 Mon Sep 17 00:00:00 2001
From: "Lyekluo." <132440008+Lyekluo@users.noreply.github.com>
Date: Tue, 3 Nov 2026 15:07:46 +0800
Subject: [PATCH] Line 136: corrected to ">>> from math import gcd" for Python
 3.9+

In Python 3.9+, gcd was removed from the fractions module and moved to the built-in math module. The current code would raise an ImportError.
This pull request updates Line 136 to use math.gcd to ensure the code runs correctly on Python 3.9 and above.
---
 sicp/2/2.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sicp/2/2.md b/sicp/2/2.md
index 0028d62..dbd8fc4 100644
--- a/sicp/2/2.md
+++ b/sicp/2/2.md
@@ -133,7 +133,7 @@ Python 中的列表（以及大多数其他编程语言中的序列）都是 **0
 如上面的例子所示，我们的有理数实现没有把有理数化简成**最简分数**（lowest terms）。要弥补这个缺陷，可以修改 `rational` 的实现。如果我们有一个计算两个整数最大公约数的函数，就能在构造「对」之前，先把分子和分母化简。和许多好用的工具一样，这样的函数 Python 标准库里早就有了。
 
 ```py
->>> from fractions import gcd
+>>> from math import gcd
 >>> def rational(n, d):
         g = gcd(n, d)
         return (n//g, d//g)