{ "metadata": { "name": "", "signature": "sha256:81f953770b0acac35782d6d61b5968cf0c7681b2e047ca75cfe8abd7244d5bab" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "

Chapter 11: Pointers

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

Example 11.1, Page 11.2

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "\n", "u,v=[3],[]\n", "pu=u\n", "v=pu\n", "pv=v\n", "\n", "print \"u=\",u[0],\n", "print \"&u=\",id(u),\n", "print \"pu=\",id(u),\n", "print \"*pu\",pu[0]\n", "\n", "print \"v=\",v[0],\n", "print \"&v=\",id(v),\n", "print \"pv=\",id(v),\n", "print \"*pv\",pv[0]\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "u= 3 &u= 56575840 pu= 56575840 *pu 3\n", "v= 3 &v= 56575840 pv= 56575840 *pv 3\n" ] } ], "prompt_number": 11 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.2, Page number: 11.3

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "v=[3]\n", "u1=2*(v[0]+5)\n", "pv=v\n", "u2=2*(pv[0]+5)\n", "\n", "print \"u1=%d u2=%d\" %(u1,u2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "u1=16 u2=16\n" ] } ], "prompt_number": 12 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.3, Page munber: 11.4

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "v=[3]\n", "pv=v\n", "print \"*pv=%d v=%d\" %(pv[0],v[0])\n", "\n", "pv[0]=0\n", "print \"*pv=%d v=%d\" %(pv[0],v[0])" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "*pv=3 v=3\n", "*pv=0 v=0\n" ] } ], "prompt_number": 13 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.7, Page number: 11.6

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "def funct1(u,v):\n", " u=0\n", " v=0\n", " print \"Within funct1 : u=%d v=%d\" %(u,v)\n", " return\n", "\n", "def funct2(u,v):\n", " u[0]=0\n", " v[0]=0\n", " print \"Within funct2 : *pu=%d *pv=%d\" %(u[0],v[0])\n", " return\n", "\n", "u=[1]\n", "v=[3]\n", "\n", "print \"Before calling funct1: u=%d v=%d\" %(u[0],v[0])\n", "funct1(u[0],v[0])\n", "print \"After calling funct1 : u=%d v=%d\" %(u[0],v[0])\n", "\n", "print \"Before calling funct2: u=%d v=%d\" %(u[0],v[0])\n", "funct2(u,v)\n", "print \"After calling funct2 : u=%d v=%d\" %(u[0],v[0])" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Before calling funct1: u=1 v=3\n", "Within funct1 : u=0 v=0\n", "After calling funct1 : u=1 v=3\n", "Before calling funct2: u=1 v=3\n", "Within funct2 : *pu=0 *pv=0\n", "After calling funct2 : u=0 v=0\n" ] } ], "prompt_number": 14 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.8, Page number: 11.8

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "\n", "def scan_line(line,pv,pc,pd,pw,po):\n", "\n", " for c in line:\n", "\n", " if c=='A' or c=='E' or c=='I' or c=='O' or c=='U':\n", " pv[0]+=1\n", " elif c>='A' and c<='Z':\n", " pc[0]+=1\n", " elif c>='0' and c<='9':\n", " pd[0]+=1\n", " elif c==' ' or c=='\\t':\n", " pw[0]+=1\n", " else:\n", " po[0]+=1\n", "\n", " return\n", "\n", "\n", "vowel,consonants,digits,whitespc,other=[0],[0],[0],[0],[0]\n", "line=\"Personal computers with memories in excess of 4096 KB are now quite common.\"\n", "line=line.upper()\n", "scan_line(line,vowel,consonants,digits,whitespc,other)\n", "print \"\\n\\n\"\n", "print \"No. of vowels : \",vowel[0]\n", "print \"No. of consonants : \",consonants[0]\n", "print \"No. of digits : \",digits[0]\n", "print \"No. of whitespace characters : \",whitespc[0]\n", "print \"No. of other characters : \",other[0]" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", "\n", "No. of vowels : 23\n", "No. of consonants : 35\n", "No. of digits : 4\n", "No. of whitespace characters : 12\n", "No. of other characters : 1\n" ] } ], "prompt_number": 15 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.12, Page number: 11.15

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "x=[10,11,12,13,14,15,16,17,18,19]\n", "\n", "for i in range(0,10):\n", " print \"i=%d x[i]=%d *(x+1)=%d\" %(i,x[i],x[i]),\n", " print \" &x[i]=\",id(x[i]),\n", " print \" x+i=\",id(x[i])" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "i=0 x[i]=10 *(x+1)=10 &x[i]= 30696620 x+i= 30696620\n", "i=1 x[i]=11 *(x+1)=11 &x[i]= 30696608 x+i= 30696608\n", "i=2 x[i]=12 *(x+1)=12 &x[i]= 30696596 x+i= 30696596\n", "i=3 x[i]=13 *(x+1)=13 &x[i]= 30696584 x+i= 30696584\n", "i=4 x[i]=14 *(x+1)=14 &x[i]= 30696572 x+i= 30696572\n", "i=5 x[i]=15 *(x+1)=15 &x[i]= 30696560 x+i= 30696560\n", "i=6 x[i]=16 *(x+1)=16 &x[i]= 30696548 x+i= 30696548\n", "i=7 x[i]=17 *(x+1)=17 &x[i]= 30696536 x+i= 30696536\n", "i=8 x[i]=18 *(x+1)=18 &x[i]= 30696524 x+i= 30696524\n", "i=9 x[i]=19 *(x+1)=19 &x[i]= 30696512 x+i= 30696512\n" ] } ], "prompt_number": 16 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.14, Page number: 11.17

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "def main():\n", " global x\n", " y=\"This string is declared within main\"\n", " y=list(y)\n", " x=list(x)\n", " print x\n", " print y\n", "\n", " return\n", "\n", "x=\"This string is declared externally\"\n", "main()\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "['T', 'h', 'i', 's', ' ', 's', 't', 'r', 'i', 'n', 'g', ' ', 'i', 's', ' ', 'd', 'e', 'c', 'l', 'a', 'r', 'e', 'd', ' ', 'e', 'x', 't', 'e', 'r', 'n', 'a', 'l', 'l', 'y']\n", "['T', 'h', 'i', 's', ' ', 's', 't', 'r', 'i', 'n', 'g', ' ', 'i', 's', ' ', 'd', 'e', 'c', 'l', 'a', 'r', 'e', 'd', ' ', 'w', 'i', 't', 'h', 'i', 'n', ' ', 'm', 'a', 'i', 'n']\n" ] } ], "prompt_number": 17 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.16, Page number: 11.19

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "def reorder(x):\n", " n=len(x)\n", " for item in range(0,n-1):\n", " for i in range(item+1,n):\n", " if x[i]Example 11.17, Page number: 11.21

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "i=[4]\n", "i[0]=1\n", "f=0.3\n", "d=0.005\n", "c='*'\n", "\n", "px=i\n", "print 'Values: i=%d f=%f d=%f c=%c \\n' %(i[0],f,d,c)\n", "print 'Addresses: &i=%X &f=%X &d=%X &c=%X \\n' %(id(i[0]),id(f),id(d),id(c))\n", "print 'Pointer Values: px=%X px+1=%X px+2=%X px+3=%X' %(id(px[0]),id(px[0]+1),id(px[0]+2),id(px[0]+3))\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Values: i=1 f=0.300000 d=0.005000 c=* \n", "\n", "Addresses: &i=1D46518 &f=32BD940 &d=32BD950 &c=1D9F158 \n", "\n", "Pointer Values: px=1D46518 px+1=1D4650C px+2=1D46500 px+3=1D464F4\n" ] } ], "prompt_number": 19 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.18, Page number: 11.22

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "a=[1,2,3,4,5,6]\n", "\n", "px=a[0]\n", "py=a[5]\n", "\n", "print 'px=%X py=%X \\n' %(id(px),id(py))\n", "print 'py - px = %X' %(id(py)-id(px))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "px=1D46518 py=1D464DC \n", "\n", "py - px = -3C\n" ] } ], "prompt_number": 20 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.22, Page number: 11.26

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "def readinput(m,n,i=0):\n", "\n", " at=[]\n", " for row in range(0,m):\n", " temp=[]\n", " for col in range(0,n):\n", " t=i\n", " i+=2\n", " temp.append(t)\n", " at.append(temp)\n", "\n", "\n", " return at\n", " \n", "def computesum(a,b,m,n):\n", "\n", " c=[]\n", "\n", " for row in range(0,m):\n", " temp=[]\n", " for col in range(0,n):\n", " t=a[row][col]+b[row][col]\n", " temp.append(t)\n", " c.append(temp)\n", "\n", " return c\n", "\n", "def writeoutput(c,m,n):\n", "\n", " for row in range(0,m):\n", " for col in range(0,n):\n", " print \"%4d\" %(c[row][col]),\n", " print\n", "\n", " return\n", "\n", "\n", "\n", "print \"\\n FIRST TABLE : \\n\"\n", "a=readinput(5,5,1)\n", "writeoutput(a,5,5)\n", "\n", "print \"\\n SECOND TABLE : \\n\"\n", "b=readinput(5,5,50)\n", "writeoutput(b,5,5)\n", "\n", "c=computesum(a,b,5,5)\n", "print \"Sums of the elements : \\n\"\n", "writeoutput(c,5,5)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", " FIRST TABLE : \n", "\n", " 1 3 5 7 9\n", " 11 13 15 17 19\n", " 21 23 25 27 29\n", " 31 33 35 37 39\n", " 41 43 45 47 49\n", "\n", " SECOND TABLE : \n", "\n", " 50 52 54 56 58\n", " 60 62 64 66 68\n", " 70 72 74 76 78\n", " 80 82 84 86 88\n", " 90 92 94 96 98\n", "Sums of the elements : \n", "\n", " 51 55 59 63 67\n", " 71 75 79 83 87\n", " 91 95 99 103 107\n", " 111 115 119 123 127\n", " 131 135 139 143 147\n" ] } ], "prompt_number": 21 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.24, Page number: 11.31

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "def readinput(m,n,i=0):\n", "\n", " at=[]\n", " for row in range(0,m):\n", " temp=[]\n", " for col in range(0,n):\n", " t=i\n", " i+=2\n", " temp.append(t)\n", " at.append(temp)\n", "\n", "\n", " return at\n", " \n", "def computesum(a,b,m,n):\n", "\n", " c=[]\n", "\n", " for row in range(0,m):\n", " temp=[]\n", " for col in range(0,n):\n", " t=a[row][col]+b[row][col]\n", " temp.append(t)\n", " c.append(temp)\n", "\n", " return c\n", "\n", "def writeoutput(c,m,n):\n", "\n", " for row in range(0,m):\n", " for col in range(0,n):\n", " print \"%4d\" %(c[row][col]),\n", " print\n", "\n", " return\n", "\n", "\n", "\n", "print \"\\n FIRST TABLE : \\n\"\n", "a=readinput(5,5,1)\n", "writeoutput(a,5,5)\n", "\n", "print \"\\n SECOND TABLE : \\n\"\n", "b=readinput(5,5,50)\n", "writeoutput(b,5,5)\n", "\n", "c=computesum(a,b,5,5)\n", "print \"Sums of the elements : \\n\"\n", "writeoutput(c,5,5)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", " FIRST TABLE : \n", "\n", " 1 3 5 7 9\n", " 11 13 15 17 19\n", " 21 23 25 27 29\n", " 31 33 35 37 39\n", " 41 43 45 47 49\n", "\n", " SECOND TABLE : \n", "\n", " 50 52 54 56 58\n", " 60 62 64 66 68\n", " 70 72 74 76 78\n", " 80 82 84 86 88\n", " 90 92 94 96 98\n", "Sums of the elements : \n", "\n", " 51 55 59 63 67\n", " 71 75 79 83 87\n", " 91 95 99 103 107\n", " 111 115 119 123 127\n", " 131 135 139 143 147\n" ] } ], "prompt_number": 22 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.26, Page number: 11.34

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "def reorder(x):\n", "\n", " n=len(x)\n", " for item in range(0,n-1):\n", " for i in range(item+1,n):\n", " if x[item]>x[i]:\n", " temp=x[item]\n", " x[item]=x[i]\n", " x[i]=temp\n", "\n", "\n", " return\n", "\n", "x=['PACIFIC','ATLANTIC','INDIAN','CARIBBEAN','BERING','BLACK','RED','NORTH','BALTIC','CASPIAN']\n", "print 'Original list of strings :\\n\\n'\n", "\n", "for i in x:\n", " print \"String : \",i\n", "\n", "reorder(x)\n", "\n", "print \"\\nReodered list of strings : \\n\\n\"\n", "\n", "for i in x:\n", " print \"String : \",i" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Original list of strings :\n", "\n", "\n", "String : PACIFIC\n", "String : ATLANTIC\n", "String : INDIAN\n", "String : CARIBBEAN\n", "String : BERING\n", "String : BLACK\n", "String : RED\n", "String : NORTH\n", "String : BALTIC\n", "String : CASPIAN\n", "\n", "Reodered list of strings : \n", "\n", "\n", "String : ATLANTIC\n", "String : BALTIC\n", "String : BERING\n", "String : BLACK\n", "String : CARIBBEAN\n", "String : CASPIAN\n", "String : INDIAN\n", "String : NORTH\n", "String : PACIFIC\n", "String : RED\n" ] } ], "prompt_number": 23 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.28, Page number: 11.37

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "def convert(mm,dd,yy):\n", " yy-=1900\n", " ndays=long(30.42*(mm-1)+dd)\n", " if mm==2:\n", " ndays+=1\n", " if mm>2 and mm<8:\n", " ndays-=1\n", " if yy%4==0 and mm<2:\n", " ndays+=1\n", "\n", " ncycles=yy/4\n", " ndays+=ncycles*1461\n", "\n", " nyears=yy%4\n", " if nyears>0:\n", " ndays+=365*nyears+1\n", " if ndays>59:\n", " ndays-=1\n", "\n", " day=ndays%7\n", "\n", " return day\n", "\n", "def main(mm,dd,yy):\n", " day_of_week=convert(mm,dd,yy)\n", " print \"%s, %s %d %d\" %(weekday[day_of_week],month[mm-1],dd,yy)\n", " return\n", " \n", "weekday=['Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday']\n", "month=['January','February','March','April','May','June','July','August',\\\n", " 'September','October','November','December']\n", "\n", "main(10,29,1929)\n", "print\n", "main(8,15,1945)\n", "print\n", "main(7,20,1969)\n", "print\n", "main(5,24,1997)\n", "print\n", "main(8,30,2010)\n", "print\n", "main(4,12,2069)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Tuesday, October 29 1929\n", "\n", "Wednesday, August 15 1945\n", "\n", "Sunday, July 20 1969\n", "\n", "Saturday, May 24 1997\n", "\n", "Monday, August 30 2010\n", "\n", "Friday, April 12 2069\n" ] } ], "prompt_number": 24 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 11.30, Page number: 11.44

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "def ratio_choose(freq,a,m,n):\n", "\n", " if freq=='C':\n", " ratio=md3(a,m,n)\n", " elif freq=='D':\n", " ratio=md2(a,m,n)\n", " else:\n", " ratio=md1(a,m,n)\n", "\n", " return ratio\n", "\n", "\n", "def table(freq,a,m,n):\n", "\n", "\n", " print \"Interest Rate Future Amount\\n\\n\"\n", " for count in range(1,21):\n", " i=0.01*count\n", " f=a*ratio_choose(freq,i,m,n)\n", " print \" %2d %.2f\" %(count,f)\n", "\n", " return\n", "\n", "def md1(i,m,n):\n", " \n", " factor=1+i/m\n", " ratio=12*(factor**(m*n)-1)/i\n", " return ratio\n", "\n", "def md2(i,m,n):\n", "\n", " factor=1+i/m\n", " ratio=(factor**(m*n)-1)/(factor**(m/12)-1)\n", " return ratio\n", "\n", "def md3(i,dummy,n):\n", " ratio=(10**(i*n)-1)/(10**(i/12)-1)\n", " return ratio\n", "\n", "def main(freq):\n", " m=0\n", " freq=freq.upper()\n", " if freq=='A':\n", " m=1\n", " print \"\\nAnual Compounding\\n\"\n", " \n", " elif freq=='S':\n", " m=2\n", " print \"\\nSemiannual Compounding\\n\"\n", " \n", " elif freq=='Q':\n", " print \"\\nQuaterly Compounding\\n\"\n", " m=4\n", " \n", " elif freq=='M':\n", " m=12\n", " print \"\\nMonthly Compounding\\n\"\n", " \n", " elif freq=='D':\n", " m=360\n", " print \"\\nDaily Compounding\\n\"\n", "\n", " elif freq=='C':\n", " m=0\n", " print \"\\nContinuous Compounding\\n\"\n", " \n", " else:\n", " print \"\\nERROR!!! Please Repeat\\n\\n\"\n", " return\n", " \n", " return m\n", "\n", "\n", "a,n,freq=100,3,'m'\n", "print \"FUTURE VALUE OF A SERIES OF MONTHLY DEPOSITS\\n\\n\"\n", "print \"Frequency of Compunding (A,S,Q,M,D,C): \",freq\n", "print \"Amount of Each Monthly Payement : \",a\n", "print \"Number of years: \",n\n", "m=main(freq)\n", "\n", "table(freq,a,m,n)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "FUTURE VALUE OF A SERIES OF MONTHLY DEPOSITS\n", "\n", "\n", "Frequency of Compunding (A,S,Q,M,D,C): m\n", "Amount of Each Monthly Payement : 100\n", "Number of years: 3\n", "\n", "Monthly Compounding\n", "\n", "Interest Rate Future Amount\n", "\n", "\n", " 1 3653.00\n", " 2 3707.01\n", " 3 3762.06\n", " 4 3818.16\n", " 5 3875.33\n", " 6 3933.61\n", " 7 3993.01\n", " 8 4053.56\n", " 9 4115.27\n", " 10 4178.18\n", " 11 4242.31\n", " 12 4307.69\n", " 13 4374.33\n", " 14 4442.28\n", " 15 4511.55\n", " 16 4582.17\n", " 17 4654.18\n", " 18 4727.60\n", " 19 4802.45\n", " 20 4878.78\n" ] } ], "prompt_number": 25 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 25 } ], "metadata": {} } ] }