{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 1 基础 课后练习及补充"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1.1 数据类型相关练习"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 1.1.1 数据类型转换\n",
    "运行下面单元格，了解`int()`，`float()`，`str()`，`type()`等的用法"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# str -> int\n",
    "X = int('ABCD', 16)\n",
    "print(X)\n",
    "type(X)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# int -> float\n",
    "a = 520\n",
    "b = float(a)\n",
    "b"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# float -> str\n",
    "a = 5.99\n",
    "b = str(a)\n",
    "b"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "接下来，请尝试将字符串`'520'`转化为小数，可以使用`float()`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "a = '520'\n",
    "b = "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "运行下面单元格，了解字符串的切片操作"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "a_string = 'Hello' + ' ' + \"Women Who Code!\"\n",
    "print(a_string)\n",
    "print(\"str[0]  :\" + a_string[0])\n",
    "print(\"str[2:5]:\" + a_string[2:5]) # Python speak: slicing\n",
    "print(\"str[2:] :\" + a_string[2:])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1.2 列表操作"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "列表是个框，什么都可以往里装"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "lis = [ \"WWCode\", 786 , 2.23, 'singapore', 70.2 ]\n",
    "print(lis[0:3])\n",
    "type(lis)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "列表的索引，先猜猜下面这个单元格能得到什么，再运行"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "lis[0][2:]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "如果我想从`lis`里得到`'sing'`应该怎么做呢"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "列表的元素是可以修改的"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "lis[2] = 3.3\n",
    "lis"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "请尝试将列表最后一个元素更改为50"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "列表有一个非常好用的操作，叫list comprehension，可以运行下面单元格感受一下"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "symbols = '$¢£¥€¤'\n",
    "codes = [ord(symbol) for symbol in symbols]\n",
    "codes"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "`ord()`的作用是返回符号的unicode编码"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1.3 元组操作"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "t1 = ( \"WWCode\", 100000 , 0.5 ) # org name, members, proportion of engineers\n",
    "t2 = 'Singapore', 1160.5\n",
    "t_singleton = ('We',) # singleton\n",
    "t_empty = ()\n",
    "print(type(t1)); print(type(t2))\n",
    "print(t_singleton);\n",
    "type(t_empty)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "元组元素不可修改，尝试运行下列代码"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "t1[2] = 20"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1.4 字典操作"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "dict1 = {'name':'Women Who Code Singapore', \n",
    "        'org':'WWCode', \n",
    "        'city':'Singapore',\n",
    "        'members':1260}\n",
    "print(dict1['org'])\n",
    "type(dict1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "字典元素可以更改"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 增加元素\n",
    "dict1['rank'] = 10"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 获取元素\n",
    "dict1['city']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 获取不知是否存在的元素\n",
    "dict1.get('org','不存在')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "dict1.get('ord','不存在')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1.5 Sets 集合  \n",
    "* Sets are a methematical concept, they are a lot like dictionaries with keys but no corresponding values. \n",
    "* 跟数学的概念很相似，类似于字典的键，但没有对应的值\n",
    "* Sets are enclosed by curly braces, elements seperated by comma, '{','}'.  \n",
    "* 用花括弧\n",
    "* Sets do not support indexing or slicing, and do not have inherent order.  \n",
    "* 不支持下标应用和切片"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "wwcode_asia_networks = {'Bangalore','Beijing','Chennai','Delhi','Gujarat','Hong Kong','Kuala Lumpur','Manila','Pune','Rajasthan','Shanghai','Singapore','Taipei','Tel-Aviv','Tokyo'}\n",
    "type(wwcode_asia_networks)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(wwcode_asia_networks)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "scrolled": true
   },
   "outputs": [],
   "source": [
    "wwcode_asia_networks[1]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1.6 运算和布尔运算"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "x = 1 + 2 # Addition\n",
    "y = 3 - 4 # Subtraction\n",
    "z = 5 * 6 # Multiplication\n",
    "a = z / y # Division\n",
    "b = z % x # Modulus\n",
    "c = y ** x # Exponent\n",
    "d = c // x # Floor Division\n",
    "print(\"x:\" + str(x) + \" y:\" + str(y) + \" z:\" + str(z) + \n",
    "      \" a:\" + str(a) + \" b:\" + str(b) + \" c:\" + str(c) + \" d:\" + str(d))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "运算符|\t描述|\t实例\n",
    "-| :-: | -\n",
    "=\t|简单的赋值运算符\t|c = a + b 将 a + b 的运算结果赋值为 c\n",
    "+=\t|加法赋值运算符\t|c += a 等效于 c = c + a\n",
    "-=\t|减法赋值运算符\t|c -= a 等效于 c = c - a\n",
    "*=\t|乘法赋值运算符\t|c *= a 等效于 c = c * a\n",
    "/=\t|除法赋值运算符\t|c /= a 等效于 c = c / a\n",
    "%=\t|取模赋值运算符\t|c %= a 等效于 c = c % a\n",
    "**=\t|幂赋值运算符\t|c \\*\\*= a 等效于 c = c \\*\\* a\n",
    "//=\t|取整除赋值运算符\t|c //= a 等效于 c = c // a"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "布尔运算和比较运算\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(a == b) # equals\n",
    "print(a != b) # not equals\n",
    "print(a > b)  # greater than\n",
    "print(a < b)  # lesser than\n",
    "print(a >= b) # greater than or equal\n",
    "print(a <= b) # lesser than or equal"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "tags": []
   },
   "source": [
    "Logical Operators 逻辑运算符     \n",
    "and or not"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "not True"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "not 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "not 4"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "3 < 4 < 5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "3 < 4 < 2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "3 < 4 and 4 < 5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "3 < 5 or 8 > 5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "a_string = \"Women Who Code\"\n",
    "print(\"Women\" in a_string)\n",
    "print(\"Men\" not in a_string)\n",
    "print(len(\"Women Who Code\") is len(a_string))\n",
    "print(len(\"Hello World!\") is not len(a_string))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 判断闰年怎么判断呢\n",
    "year = 2100  # eval(input('输入年份（四位数）'))\n",
    "# 大家来试试\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "is 和  is not 运算符 与==以及!=的区别"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "is 用于判断两个变量引用对象是否为同一个， == 用于判断引用变量的值是否相等。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "x = 5\n",
    "y = 5\n",
    "print(x == y)\n",
    "print(x is y)\n",
    "print(id(x))\n",
    "print(id(y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "help(id)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "id(1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "id(\"abc\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "id([1, 2, 3])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "x = \"abcabcabcabcabcabcabcabcabcabc\"\n",
    "y = \"abcabcabcabcabcabcabcabcabcabc\"\n",
    "print(x == y)\n",
    "print(x is y)\n",
    "print(id(x))\n",
    "print(id(y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 数组比较\n",
    "x = [1, 2, 3]\n",
    "y = [1, 2, 3]\n",
    "print(x == y)\n",
    "print(x is y)\n",
    "print(id(x))\n",
    "print(id(y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 元组比较\n",
    "x = (1, 2, 3)\n",
    "y = (1, 2, 3)\n",
    "print(x == y)\n",
    "print(x is y)\n",
    "print(id(x))\n",
    "print(id(y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 字典比较\n",
    "x = {\"id\": 1, \"name\": \"Tom\", \"age\": 18}\n",
    "y = {\"id\": 1, \"name\": \"Tom\", \"age\": 18}\n",
    "print(x == y)\n",
    "print(x is y)\n",
    "print(id(x))\n",
    "print(id(y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 集合比较\n",
    "x = set([1, 2, 3])\n",
    "y = set([1, 2, 3])\n",
    "print(x == y)\n",
    "print(x is y)\n",
    "print(id(x))\n",
    "print(id(y))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# 赋值后比较\n",
    "x = [1, 2, 3]\n",
    "y = x\n",
    "print(x == y)\n",
    "print(x is y)\n",
    "print(id(x))\n",
    "print(id(y))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "空值比较"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "none_type = None\n",
    "none_type is None"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1.A 附录 一些可能会用到的知识\n",
    "这部分内容在使用python的过程中可能会用得上，可以逐个运行单元格感受一下~"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 1.A.1 Reserve Words保留字\n",
    "The following identifiers are used as reserved words of the language, and cannot be used as ordinary identifiers.\n",
    "一些关键字是系统自带的保留字，即不能用作为标识符"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import keyword\n",
    "keyword.kwlist"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 1.A.2 build-in functions内置函数\n",
    "这些函数不能作为变量名，可以作为函数直接调用，如：`print()` `input()`   \n",
    "`dir(\\__builtins__)`可以看到内置函数列表"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "dir(__builtins__)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "aa = 3\n",
    "aaaa = 5\n",
    "dir()  #python内置函数；不带参数时，返回当前范围内的变量、方法和定义的类型列表\n",
    "        #带参数是，返回参数的属性、方法列表"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "help(dir)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "help(print)   # 内置函数，查看函数或模块用途的详细说明"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Hit the **STOP** square button in the button ribbons/bar on top to continue to next cell."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "#help(str)\n",
    "import copy\n",
    "help(copy.copy)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "----"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "本篇整理：肖桐"
   ]
  }
 ],
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   "file_extension": ".py",
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