{ "metadata": { "name": "chapter-5.ipynb" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "

Chapter 5: Functions & Pointers

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

Message Function, Page number: 159

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def message():\n", " print \"Smile, and the world smiles with you...\" \n", "\n", "message() #function call\n", "print \"Cry, and you stop the monotony!\" \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Smile, and the world smiles with you...\n", "Cry, and you stop the monotony!\n" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Calling More Than One Funnction , Page number: 159

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definitions\n", "def italy():\n", " print \"I am in italy\" \n", " \n", "def brazil():\n", " print \"I am in brazil\" \n", "\n", "def argentina():\n", " print \"I am in argentina\" \n", " \n", "\n", "print \"I am in main\" \n", "#function calls\n", "italy()\n", "brazil()\n", "argentina()\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "I am in main\n", "I am in italy\n", "I am in brazil\n", "I am in argentina\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Function Calling Function, Page number: 161

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definitions\n", "def argentina():\n", " print \"I am in argentina\" \n", "\n", "def brazil():\n", " print \"I am in brazil\" \n", " argentina() #function call\n", "\n", "def italy():\n", " print \"I am in italy\" \n", " brazil() #function call\n", " print \"I am back in italy\" \n", " \n", "print \"I am in main\" \n", "#function call\n", "italy()\n", "print \"I am finally back in main\" " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "I am in main\n", "I am in italy\n", "I am in brazil\n", "I am in argentina\n", "I am back in italy\n", "I am finally back in main\n" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Calsum Function , Page number: 166

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def calsum ( x, y, z ):\n", " d = x + y + z\n", " return d\n", "\n", "#Input from user\n", "#a,b,c = raw_input (\"Enter any three numbers: \").split()\n", "print \"Enter any three numbers: \"\n", "a = 10\n", "b = 20\n", "c = 30\n", "print a,b,c\n", "\n", "#function call\n", "s = calsum(a,b,c) \n", "\n", "#Result\n", "print \"Sum = \", s \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Enter any three numbers: \n", "10 20 30\n", "Sum = 60\n" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Return Statement , Page number: 169

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "statements that may be present in a function.\n", "Also, the return statement need not always be present at the end of the called\n", "\n", "# function definition\n", "def fun():\n", " #Input from user\n", " #ch = raw_input (\"Enter any alphabet: \")\n", " print \"Enter any alphabet: \"\n", " ch = 'a'\n", " print ch\n", " ch = ord(ch)\n", " if ch >= 65 and ch <= 90:\n", " return ascii(ch)\n", " else:\n", " return ascii( ch + 32 )\n", "\n", "#function call\n", "ch = fun()\n", "\n", "#Result\n", "print ch\n" ], "language": "python", "metadata": {}, "outputs": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Formal Arguments, Page number: 170

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "changed in the called function, the corresponding\n", "\n", "# function definition\n", "def fun(b):\n", " b = 60\n", " print b \n", "\n", "a = 30\n", "fun(a) #function call\n", "print a" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "60\n", "30\n" ] } ], "prompt_number": 9 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Scope Rule of Functions , Page number: 171

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def display(j):\n", " k = 35\n", " print j\n", " print k\n", "\n", "i = 20 \n", "display(i) #function call\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "20\n", "35\n" ] } ], "prompt_number": 10 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Square Function , Page number: 176

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def square(x):\n", " y = x * x\n", " return y\n", "\n", "#Input from user\n", "#a = raw_input(\"Enter any number: \")\n", "print \"Enter any number: \"\n", "a = 4.5\n", "print a\n", "\n", "b = square(a) #function call\n", "\n", "#Result\n", "print \"Square of %f is %f\" %( a, b )\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Enter any number: \n", "4.5\n", "Square of 4.500000 is 20.250000\n" ] } ], "prompt_number": 11 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Void Function , Page number: 177

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def gospel(): # void function\n", " print \"Viruses are electronic bandits...\" \n", " print \"who eat nuggets of information...\" \n", " print \"and chunks of bytes...\" \n", " print \"when you least expect...\" \n", "\n", "gospel() # function call" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Viruses are electronic bandits...\n", "who eat nuggets of information...\n", "and chunks of bytes...\n", "when you least expect...\n" ] } ], "prompt_number": 12 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Address of a Variable , Page number: 180

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "i = 3\n", "\n", "#Result\n", "print \"Address of i = \" , id(i) #printing address\n", "print \"Value of i = \", i \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Address of i = 30301288\n", "Value of i = 3\n" ] } ], "prompt_number": 13 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Pointer Relations , Page number: 182

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "i = 3 \n", "j = id(i) # address of variable 'i'\n", "\n", "#Result\n", "print \"Address of i = \", id(i) \n", "print \"Address of i = \", j \n", "print \"Address of j = \", id(j)\n", "print \"Value of j = \", j \n", "print \"Value of i = \", i \n", "print \"Value of i = \", i \n", "print \"Value of i = \", i \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Address of i = 30301288\n", "Address of i = 30301288\n", "Address of j = 134133200\n", "Value of j = 30301288\n", "Value of i = 3\n", "Value of i = 3\n", "Value of i = 3\n" ] } ], "prompt_number": 14 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Pointer to Another Pointer , Page number: 184

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "i = 3\n", "j = id(i) # address of i\n", "k = id(j) # address of j\n", "\n", "#Result\n", "print \"Address of i = \", id(i) \n", "print \"Address of i = \", j \n", "print \"Address of i = \", j \n", "print \"Address of j = \", id(j) \n", "print \"Address of j = \", k \n", "print \"Address of k = \", id(k)\n", "print \"Value of j = \", j \n", "print \"Value of k = \", k \n", "print \"Value of i = \", i \n", "print \"Value of i = \", i \n", "print \"Value of i = \", i \n", "print \"Value of i = \", i " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Address of i = 30301288\n", "Address of i = 30301288\n", "Address of i = 30301288\n", "Address of j = 134132944\n", "Address of j = 134132944\n", "Address of k = 134133200\n", "Value of j = 30301288\n", "Value of k = 134132944\n", "Value of i = 3\n", "Value of i = 3\n", "Value of i = 3\n", "Value of i = 3\n" ] } ], "prompt_number": 15 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Call By Value , Page number: 186

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def swapv (x,y):\n", " x,y=y,x\n", " print \"x = %d y = %d\" %( x, y )\n", "\n", "#Variable declaration\n", "a = 10\n", "b = 20\n", "\n", "swapv ( a, b ) # function call\n", "\n", "#Result\n", "print \"a = %d b = %d\" %( a, b )\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "x = 20 y = 10\n", "a = 10 b = 20\n" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Call By Reference , Page number: 187

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def swapv (a,b):\n", " a,b=b,a\n", " return a,b\n", "\n", "#Variable declaration\n", "a = 10\n", "b = 20\n", "\n", "a,b = swapv ( a, b ) # function call\n", "\n", "#Result\n", "print \"a = %d b = %d\" %( a, b )" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "a = 20 b = 10\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Area And Perimeter of a Circle , Page number: 188

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Input from user\n", "#radius = raw_input(\"Enter radius of a circle: \" )\n", "print \"Enter radius of a circle: \"\n", "radius = 5\n", "print radius\n", "\n", "#Function definition\n", "def areaperi ( r ):\n", " a = 3.14 * r * r\n", " p = 2 * 3.14 * r \n", " return a,p\n", "\n", "area,perimeter = areaperi ( radius ) #function call\n", "\n", "\n", "#Result\n", "print \"Area = \", area \n", "print \"Perimeter = \", perimeter " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Enter radius of a circle: \n", "5\n", "Area = 78.5\n", "Perimeter = 31.4\n" ] } ], "prompt_number": 18 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Iterative Factorial Function , Page number: 190

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def factorial(x):\n", " f = 1\n", " for i in range(x,0,-1 ):\n", " f = f * i\n", " return f\n", "\n", "#Input from user\n", "#a = raw_input( \"Enter any number: \" )\n", "print \"Enter any number: \"\n", "a = 6\n", "print a\n", "\n", "fact = factorial(a) #function call\n", "\n", "#Result\n", "print \"Factorial value = \", fact\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Enter any number: \n", "6\n", "Factorial value = 720\n" ] } ], "prompt_number": 19 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Recursive Factorial Function, Page number: 191

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# function definition\n", "def rec(x):\n", " if x == 1:\n", " return 1\n", " else:\n", " f = x * rec ( x - 1 ) # calling the function\n", " return f\n", "\n", "#Input from user\n", "#a = raw_input( \"Enter any number: \" )\n", "print \"Enter any number: \"\n", "a = 5\n", "print a\n", "\n", "fact = rec(a) #function call\n", "\n", "#Result\n", "print \"Factorial value = \", fact \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Enter any number: \n", "5\n", "Factorial value = 120\n" ] } ], "prompt_number": 20 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Recursion Stack , Page number: 195

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "a = 5\n", "b = 2\n", "\n", "#Function definition\n", "def add ( i, j ):\n", " s = i + j\n", " return s\n", "\n", "c = add ( a, b ) # function call\n", "\n", "#Result\n", "print \"sum = \", c " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "sum = 7\n" ] } ], "prompt_number": 21 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }