small updates on lesson1

Yimeng-Zhang · web-flow · commit b04046680d06 · 2017-02-21T18:13:02.000+08:00
edited by Yimeng Zhang
diff --git a/python_basic/python_basic_lesson_01.ipynb b/python_basic/python_basic_lesson_01.ipynb
@@ -2,12 +2,14 @@
  "cells": [
   {
    "cell_type": "markdown",
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "source": [
     "# Lesson 1\n",
-    "\n",
     "Python Basic, Lesson 1, v1.0.1, 2016.12 by David.Yi\n",
     "\n",
+    "Python Basic, Lesson 1, v1.0.2, 2017.02 modified by Eamon.Zhang\n",
     "\n",
     "### 本次内容要点\n",
     "\n",
@@ -18,12 +20,15 @@
     "    * jupyter 和 notebook介绍\n",
     "* 基本变量概念\n",
     "* print() 和 input() 用法\n",
-    "* pycharm 用法介绍"
+    "* pycharm 用法介绍\n",
+    "\n"
    ]
   },
   {
    "cell_type": "markdown",
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "source": [
     "### python 简介\n",
     "\n",
@@ -44,7 +49,11 @@
     "\n",
     "Python 2.0于2000年10月16日发布，增加了实现完整的垃圾回收，并且支持Unicode。同时，整个开发过程更加透明，社区对开发进度的影响逐渐扩大。目前2系列的最新版本是 2.7.12，2.7版本将在2020年被停止支持。\n",
     "\n",
-    "Python 3.0于2008年12月3日发布，此版不完全兼容之前的Python源代码。不过，很多新特性后来也被移植到旧的Python 2.6/2.7版本。目前3系列版本是3.5.2，3.6已经在 beta 测试中。\n",
+    "Python 3.0于2008年12月3日发布，此版不完全兼容之前的Python源代码。不过，很多新特性后来也被移植到旧的Python 2.6/2.7版本。目前最新版本是3.6.0，发布于2016年12月。\n",
+    "\n",
+    "#### Python能做什么？\n",
+    "\n",
+    "![](imgs/python_use.jpg)\n",
     "\n",
     "#### 设计哲学\n",
     "\n",
@@ -62,7 +71,9 @@
   },
   {
    "cell_type": "markdown",
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "source": [
     "### 准备工作\n",
     "\n",
@@ -136,7 +147,9 @@
   },
   {
    "cell_type": "markdown",
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "source": [
     "### 基本变量概念\n",
     "\n",
@@ -158,14 +171,15 @@
    "outputs": [],
    "source": [
     "counter = 100  # 整型变量\n",
-    "miles = 1000.0 # 浮点型\n",
+    "miles = 1000.0 # 浮点型（小数）\n",
     "name = \"John\"  # 字符串\n",
-    "name2 = 'Tom'"
+    "name2 = 'Tom'\n",
+    "bool = True  # 布尔值"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 1,
    "metadata": {
     "collapsed": false
    },
@@ -214,7 +228,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 21,
+   "execution_count": 2,
    "metadata": {
     "collapsed": false
    },
@@ -234,6 +248,44 @@
     "print(a,b)"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#### 动态语言\n",
+    "Python是动态语言，即变量本身的类型不固定\n",
+    "\n",
+    "与之对应的静态语言（如Java），在定义变量时，必须先指定变量类型，赋值时如不匹配则报错"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "#### 理解Python变量在内存中的表示\n",
+    "当我们输入 a = 'yimeng' 时，Python解释器做了2件事情：\n",
+    "\n",
+    "1 在内存中创建了一个'yimeng'的字符串；\n",
+    "\n",
+    "2 在内存中创建了一个名为a的变量，并把它指向'yimeng'。\n",
+    "\n",
+    "也可以把一个变量a赋值给另一个变量b，这个操作实际上是把变量b指向变量a所指向的数据"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "a = 'ABC'\n",
+    "b = a\n",
+    "a = 'XYZ'\n",
+    "#print(b)"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -277,7 +329,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 22,
+   "execution_count": 3,
    "metadata": {
     "collapsed": false
    },
@@ -298,7 +350,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 3,
    "metadata": {
     "collapsed": false
    },
@@ -321,7 +373,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 4,
    "metadata": {
     "collapsed": false
    },
@@ -339,12 +391,15 @@
       "6\n",
       "7\n",
       "8\n",
-      "9\n"
+      "9\n",
+      "10\n",
+      "11\n",
+      "12\n"
      ]
     }
    ],
    "source": [
-    "for i in range(10):\n",
+    "for i in range(13):\n",
     "    print(i)"
    ]
   },
@@ -397,7 +452,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 5,
    "metadata": {
     "collapsed": false
    },
@@ -406,19 +461,26 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
+      "hello from English\n",
       "hello from English\n"
      ]
     }
    ],
    "source": [
-    "# 更加好，更加 pythonic 的写法\n",
+    "# 更加好，更加 pythonic 的写法：format函数-增强的格式化字符串函数\n",
+    "# 关于format的更多细节，参见 https://docs.python.org/3/library/string.html#format-string-syntax\n",
+    "# 通过关键字传参\n",
+    "print('{greet} from {language}'.format(greet='hello', language='English'))\n",
     "\n",
-    "print('{greet} from {language}'.format(greet='hello', language='English'))"
+    "# 通过位置传参\n",
+    "print('{0} from {1}'.format('hello', 'English'))"
    ]
   },
   {
    "cell_type": "markdown",
-   "metadata": {},
+   "metadata": {
+    "collapsed": true
+   },
    "source": [
     "---\n",
     "\n",
@@ -518,7 +580,7 @@
  "metadata": {
   "anaconda-cloud": {},
   "kernelspec": {
-   "display_name": "Python [default]",
+   "display_name": "Python 3",
    "language": "python",
    "name": "python3"
   },
@@ -532,7 +594,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.2"
+   "version": "3.5.1"
   }
  },
  "nbformat": 4,
