From a5df74d1215676fa1a97fe742316c8cb72fd31ea Mon Sep 17 00:00:00 2001
From: epsilon_luoo <epsilon_luoo@outlook.com>
Date: Fri, 8 Jul 2022 16:17:54 +0800
Subject: [PATCH] fix issues

---
 1. Python 安装及基本语法.ipynb |  2 +-
 3. Python 面向对象编程.ipynb   | 15 ++++++++-------
 4. Python 文件与模块.ipynb     |  2 +-
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/1. Python 安装及基本语法.ipynb b/1. Python 安装及基本语法.ipynb
index 545f61c..15f3530 100644
--- a/1. Python 安装及基本语法.ipynb	
+++ b/1. Python 安装及基本语法.ipynb	
@@ -517,7 +517,7 @@
     "    - `<<` 表示左移操作\n",
     "    - `&` 表示按位与\n",
     "    - `|` 表示按位或\n",
-    "    - `^` 表示按位亦或\n",
+    "    - `^` 表示按位异或\n",
     "    - `~` 表示按位取反\n",
     "    \n",
     "其中最常用的是算数运算符与逻辑运算符，位运算符在 集合 操作中经常使用。\n",
diff --git a/3. Python 面向对象编程.ipynb b/3. Python 面向对象编程.ipynb
index 70b8a8b..221c10e 100644
--- a/3. Python 面向对象编程.ipynb	
+++ b/3. Python 面向对象编程.ipynb	
@@ -266,7 +266,7 @@
     "## 创建一个 student 类\n",
     "class student():\n",
     "    ## 类的内部定义三个内部变量，并定义他们的初始值\n",
-    "    name = 'Undifined'\n",
+    "    name = 'Undefined'\n",
     "    math_score = -1\n",
     "    language_score = -1"
    ]
@@ -430,7 +430,7 @@
     "    def print_name(self,):\n",
     "        print(self.name)\n",
     "        \n",
-    "    name = 'Undifined'\n",
+    "    name = 'Undefined'\n",
     "    math_score = -1\n",
     "    language_score = -1"
    ]
@@ -485,15 +485,16 @@
     "    def change_score(self, course_name, score):\n",
     "        if course_name == 'math':\n",
     "            self.math_score = score\n",
-    "        if course_name == 'language':\n",
+    "        elif course_name == 'language':\n",
     "            self.language_score = score\n",
     "        ## 如果输入的 course_name 不是 math 或者 language，则输出错误信息\n",
-    "        print(course_name, \" course is still not in current system\")\n",
+    "        else:\n",
+    "            print(course_name, \" course is still not in current system\")\n",
     "    \n",
     "    def print_name(self,):\n",
     "        print(self.name)\n",
     "        \n",
-    "    name = 'Undifined'\n",
+    "    name = 'Undefined'\n",
     "    math_score = -1\n",
     "    language_score = -1"
    ]
@@ -577,7 +578,7 @@
     "    def print_name(self,):\n",
     "        print(self.name)\n",
     "    \n",
-    "    name = 'Undifined'\n",
+    "    name = 'Undefined'\n",
     "    math_score = -1\n",
     "    language_score = -1"
    ]
@@ -1098,7 +1099,7 @@
     "    def print_name(self,):\n",
     "        print(self.name)\n",
     "    \n",
-    "    name = 'Undifined'\n",
+    "    name = 'Undefined'\n",
     "    math_score = -1\n",
     "    language_score = -1"
    ]
diff --git a/4. Python 文件与模块.ipynb b/4. Python 文件与模块.ipynb
index 6243267..d98b4fe 100644
--- a/4. Python 文件与模块.ipynb	
+++ b/4. Python 文件与模块.ipynb	
@@ -456,7 +456,7 @@
    "id": "f0673d08",
    "metadata": {},
    "source": [
-    "### 1.4.3.2 Python 之蝉"
+    "### 1.4.3.2 Python 之禅"
    ]
   },
   {