{ "metadata": { "name": "", "signature": "sha256:369d1716e7a65538ad06381f5a1cdafc97ddfbad9ccd970d060ca5c894a6593b" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "

Chapter 10: Structures and Unions

" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.1, Page Number: 223

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "class inv_type:\n", " def __init__(self):\n", " self.item=None\n", " self.cost=0\n", " self.retail=0\n", " self.on_hand=0\n", " self.lead_time=0\n", "\n", "#Variable declaration\n", "size=100 \n", "invtry = []*size\n", "i=5 #User iput for menu selection\n", "\n", "#Initialize the array\n", "def init_list():\n", " for t in range(size):\n", " invtry.append(inv_type())\n", " \n", "#get a menu selection\n", "def menu():\n", " global i\n", " print \"(E)nter\"\n", " print \"(D)isplay\"\n", " print \"(U)pdate\"\n", " print \"(Q)uit\"\n", " print \"choose one: \"\n", " i-=1\n", " return i\n", "\n", "#enter items into the list\n", "def enter():\n", " #find the first free structure\n", " for i in range(size):\n", " if not(invtry[i].item==None):\n", " break\n", " #i will be size if list is full\n", " if i==size:\n", " print \"List full.\"\n", " return\n", " input(i)\n", " \n", "#Input the information\n", "def input(i):\n", " #Enter information; User input\n", " invtry[i].item=\"Gloves\"\n", " invtry[i].cost=10\n", " invtry[i].retail=25\n", " invtry[i].on_hand=50\n", " invtry[i].lead_time=10\n", " \n", "#Modify an existing item\n", "def update():\n", " name=\"Gloves\" #User input\n", " for i in range(size):\n", " if not(name==invtry[i].item):\n", " break\n", " if i==size:\n", " print \"Item not found.\"\n", " return\n", " print \"Enter new information.\"\n", " input(i)\n", " \n", "#Display the list\n", "def display():\n", " for t in range(size):\n", " if not(invtry[t].item==None):\n", " print invtry[t].item\n", " print \"Cost: $\",invtry[t].cost\n", " print \"Retail: $\",invtry[t].retail\n", " print \"On hand: \",invtry[t].on_hand\n", " print \"Resupply time: \",invtry[t].lead_time,\" days\"\n", " \n", "\n", "init_list()\n", "while True:\n", " choice=menu()\n", " if choice==4:\n", " enter()\n", " elif choice==3:\n", " display()\n", " elif choice==2:\n", " update()\n", " elif choice==1:\n", " break" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(E)nter\n", "(D)isplay\n", "(U)pdate\n", "(Q)uit\n", "choose one: \n", "(E)nter\n", "(D)isplay\n", "(U)pdate\n", "(Q)uit\n", "choose one: \n", "Gloves\n", "Cost: $ 10\n", "Retail: $ 25\n", "On hand: 50\n", "Resupply time: 10 days\n", "(E)nter\n", "(D)isplay\n", "(U)pdate\n", "(Q)uit\n", "choose one: \n", "Enter new information.\n", "(E)nter\n", "(D)isplay\n", "(U)pdate\n", "(Q)uit\n", "choose one: \n" ] } ], "prompt_number": 11 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.2, Page Number: 226

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "class sample:\n", " a=None\n", " ch=None\n", " \n", "def f1(parm):\n", " print parm.a,\" \",parm.ch\n", "\n", "#declare arg\n", "arg=sample() \n", "\n", "#initialize arg\n", "arg.a=1000\n", "arg.ch='X'\n", "\n", "#call function\n", "f1(arg)\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "1000 X\n" ] } ], "prompt_number": 12 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.3, Page Number: 227

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "class stype:\n", " a=None\n", " b=None\n", "\n", "#Variable declaration\n", "svar1=stype()\n", "svar2=stype()\n", "\n", "svar1.a=svar1.b=10\n", "svar2.a=svar2.b=20\n", "\n", "print \"Structures before assignment.\"\n", "print \"svar1: \",svar1.a,' ',svar1.b\n", "print \"svar1: \",svar2.a,' ',svar2.b\n", "\n", "svar2=svar1 #assign structures\n", "\n", "#Result\n", "print \"\\nStructures before assignment.\"\n", "print \"svar1: \",svar1.a,' ',svar1.b\n", "print \"svar1: \",svar2.a,' ',svar2.b" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Structures before assignment.\n", "svar1: 10 10\n", "svar1: 20 20\n", "\n", "Structures before assignment.\n", "svar1: 10 10\n", "svar1: 10 10\n" ] } ], "prompt_number": 13 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.4, Page Number: 230

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import datetime\n", "\n", "date=datetime.datetime.now()\n", "\n", "#Result\n", "print date.time()" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "17:06:28.236000\n" ] } ], "prompt_number": 14 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.5, Page Number: 231

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import datetime\n", "\n", "date=datetime.datetime.now()\n", "\n", "#Result\n", "print date.ctime()" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Sat Sep 14 17:07:14 2013\n" ] } ], "prompt_number": 15 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.6, Page Number: 232

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "class mystruct:\n", " a=None\n", " b=None\n", "\n", "#Recieve and return by reference\n", "def f(var):\n", " var[0].a=var[0].a*var[0].a\n", " var[0].b=var[0].b/var[0].b\n", " return var[0]\n", " \n", "#Variable declaration\n", "x=[]\n", "x.append(mystruct())\n", "y=mystruct()\n", "\n", "#Initializing\n", "x[0].a=10\n", "x[0].b=20\n", "\n", "print \"Original x.a and x.b: \",x[0].a,' ',x[0].b\n", "\n", "y=f(x) #function call\n", "\n", "#Result\n", "print \"Modified x.a and x.b: \",x[0].a,' ',x[0].b\n", "print \"Modified y.a and y.b: \",y.a,' ',y.b\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Original x.a and x.b: 10 20\n", "Modified x.a and x.b: 100 1\n", "Modified y.a and y.b: 100 1\n" ] } ], "prompt_number": 16 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.7, Page Number: 239

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "class swap_bytes:\n", " ch=[0,0]\n", "\n", "#Exchange of bytes\n", "def disp_binary(u):\n", " t=128\n", " while not(t==0):\n", " if u&t:\n", " print \"1 \",\n", " else:\n", " print \"0 \",\n", " t=t/2\n", "\n", "#Variable declaration\n", "sb=swap_bytes()\n", "\n", "sb.ch[0]=15\n", "\n", "print \"Original bytes: \",\n", "disp_binary(sb.ch[1])\n", "disp_binary(sb.ch[0])\n", "\n", "#Exchange bytes\n", "temp=sb.ch[0]\n", "sb.ch[0]=sb.ch[1]\n", "sb.ch[1]=temp\n", "\n", "#Result\n", "print \"\\nExchanged bytes: \",\n", "disp_binary(sb.ch[1])\n", "disp_binary(sb.ch[0])\n", "\n", "\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Original bytes: 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 \n", "Exchanged bytes: 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 \n" ] } ], "prompt_number": 17 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.8, Page Number: 240

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "ch='a'\n", "\n", "while True:\n", " print \"\\n\",ch,\n", " print bin(ord(ch)) #Display the bit pattern for each character\n", " ch=chr(ord(ch)+1)\n", " if ch=='r':\n", " break" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "a 0b1100001\n", "\n", "b 0b1100010\n", "\n", "c 0b1100011\n", "\n", "d 0b1100100\n", "\n", "e 0b1100101\n", "\n", "f 0b1100110\n", "\n", "g 0b1100111\n", "\n", "h 0b1101000\n", "\n", "i 0b1101001\n", "\n", "j 0b1101010\n", "\n", "k 0b1101011\n", "\n", "l 0b1101100\n", "\n", "m 0b1101101\n", "\n", "n 0b1101110\n", "\n", "o 0b1101111\n", "\n", "p 0b1110000\n", "\n", "q 0b1110001\n" ] } ], "prompt_number": 18 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 10.9, Page Number: 242

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "ch=['X','Y']\n", "c=\"\"\n", "def disp_bits(u):\n", " t=128\n", " global c\n", " while not(t==0):\n", " if u&t:\n", " c=c+\"1\"\n", " else:\n", " c=c+\"0\"\n", " t=t/2 \n", " return c\n", "\n", "#Result\n", "print \"union as chars: \",ch[0],ch[1]\n", "print \"union as integer: \",\n", "c= disp_bits(ord(ch[1]))\n", "c= disp_bits(ord(ch[0]))\n", "print int(str(c),2)\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "union as chars: X Y\n", "union as integer: 22872\n" ] } ], "prompt_number": 19 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }