{ "metadata": { "name": "", "signature": "sha256:9a6978851f88c0c91bde88465299d72777f3dae7854964b1cadad7b80092df72" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "

Chapter 7: Functions,Part One: The Fundamentals

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

Example 7.1, Page Number: 129

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "def f1():\n", " print \"Enter something: \"\n", " str= \"Hello\" #User-input\n", " print str\n", " \n", "#Variable decleration\n", "str=\"This is str in main\"\n", "\n", "print str\n", "f1() #function call\n", "print str" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "This is str in main\n", "Enter something: \n", "Hello\n", "This is str in main\n" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.2, Page Number: 130

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable decleration\n", "choice=0\n", "\n", "print \"(1) add numbers or (2) concatenate strings?: \"\n", "choice=2 #User Input taken as 2\n", "\n", "if choice==1:\n", " print \"Enter two numbers: \"\n", " a=5 #Variable decleration; User Input\n", " b=7\n", " print a+b #Result\n", "else :\n", " print \"Enter two strings: \"\n", " s1=\"Hello\" #Variable decleration; User Input\n", " s2=\"World\"\n", " s1+=s2 #Concatenation\n", " print s1 #Result" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(1) add numbers or (2) concatenate strings?: \n", "Enter two strings: \n", "HelloWorld\n" ] } ], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.3, Page Number: 131

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable decleration\n", "i=10\n", "j=100\n", "\n", "if j>0:\n", " i=None \n", " i= j/2\n", " print \"inner i: \",i #Result\n", "\n", "print \"outer i: \",i #Result" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "inner i: 50\n", "outer i: 50\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.4, Page Number: 132

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "a=5 #Variable decleration; user input\n", "\n", "b=10 #declaration of another variable; user input\n", "\n", "#Result\n", "print \"Product: \",a*b" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Product: 50\n" ] } ], "prompt_number": 4 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.5, Page Number: 134

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import random\n", "\n", "#Variable decleration\n", "count=None\n", "num_right=0\n", "\n", "#Function for the drill\n", "def drill():\n", " #Generate two numbers between 0 and 99.\n", " a=random.randint(0,99)\n", " b=random.randint(0,99)\n", " #The user gets three tries to get it right.\n", " for count in range(3):\n", " print \"What is \",a,\" + \",b,\"? \"\n", " ans = random.randint(0,200) #user input\n", " if ans==a+b:\n", " print \"Right\"\n", " num_right+=1\n", " print \"You've used up all your tries.\"\n", " print \"The answer is \",a+b\n", " \n", "#Main function \n", "print \"How many practice problems: \"\n", "count=2 #User input taken as 2\n", "num_right=0\n", "while True:\n", " drill()\n", " count-=1\n", " if(count==0):\n", " break\n", " \n", "#Result\n", "print \"You got \",num_right,\" right. \" \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "How many practice problems: \n", "What is 9 + 89 ? \n", "What is 9 + 89 ? \n", "What is 9 + 89 ? \n", "You've used up all your tries.\n", "The answer is 98\n", "What is 85 + 98 ? \n", "What is 85 + 98 ? \n", "What is 85 + 98 ? \n", "You've used up all your tries.\n", "The answer is 183\n", "You got 0 right. \n" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.6, Page Number: 136

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from ctypes import *\n", "\n", "#Function to change the reference value\n", "def f(j):\n", " j[0]=100 #j is assigned 100\n", "\n", "#Variable decleration\n", "i=c_int(1)\n", "p=pointer(i)\n", "\n", "#Calling the function\n", "f(p) \n", "\n", "print i" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "c_long(100)\n" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.7, Page Number: 137

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from ctypes import *\n", "\n", "#Function to change the reference value\n", "def f(j):\n", " j[0]=100 #j is assigned 100\n", "\n", "#Variable decleration\n", "i=c_int(1)\n", "p=pointer(i)\n", "\n", "#Calling the function\n", "f(p) \n", "\n", "print i" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "c_long(100)\n" ] } ], "prompt_number": 6 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.8, Page Number: 137

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#function to print some nos.\n", "def display(num):\n", " for i in range(10):\n", " print num[i],\n", " \n", "#Variable declaration\n", "t=[]\n", "\n", "for i in range(10):\n", " t.append(i)\n", "#Pass list to a function\n", "display(t)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "0 1 2 3 4 5 6 7 8 9\n" ] } ], "prompt_number": 7 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.9, Page Number: 138

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Print some nos.\n", "def display(num):\n", " print num,\n", "\n", "#Variable declaration\n", "t=[]\n", "\n", "for i in range(10):\n", " t.append(i)\n", " \n", "#Printing without passing entire list\n", "for i in range(10):\n", " display(t[i])" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "0 1 2 3 4 5 6 7 8 9\n" ] } ], "prompt_number": 8 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.10, Page Number: 139

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Function to convert into cubes\n", "def cube(n,num):\n", " num-=1\n", " while num:\n", " n[num]=n[num]*n[num]*n[num]\n", " num-=1\n", "\n", "#Variable declaration\n", "nums=[]\n", "\n", "for i in range(10):\n", " nums.append(i+1)\n", " \n", "print \"Original contents: \",\n", "for i in range(10):\n", " print nums[i],\n", "print\n", "\n", "cube(nums,10) #Compute cubes\n", "\n", "#Result\n", "print \"Altered contents: \",\n", "for i in range(10):\n", " print nums[i]," ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Original contents: 1 2 3 4 5 6 7 8 9 10\n", "Altered contents: 1 8 27 64 125 216 343 512 729 1000\n" ] } ], "prompt_number": 10 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.11, Page Number: 140

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import string\n", "\n", "def stringupper(str):\n", " str=string.upper(str) #convert to uppercase\n", " return str\n", "\n", "#Variable declaration \n", "str=\"this is a test\"\n", "\n", "#Calling the function\n", "str=stringupper(str)\n", "\n", "#Result\n", "print str" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "THIS IS A TEST\n" ] } ], "prompt_number": 7 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.12, Page Number: 141

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Function to fond length\n", "def mystrlen(str):\n", " l=len(str)\n", " return l\n", "\n", "#Result\n", "print \"Length of Hello There is: \",\n", "print mystrlen(\"Hello There\")" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Length of Hello There is: 11\n" ] } ], "prompt_number": 11 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.13, Page Number: 142

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import sys\n", "\n", "def main():\n", " if len(sys.argv)!=2:\n", " print \"You forgot to type your name.\" #CHECK!!!!\n", " return\n", " #Result\n", " print \"Hello \",sys.argv[1]\n", "\n", "main()" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "You forgot to type your name.\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.14, Page Number: 143

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "'''The program prints all command line arguments '''\n", "import sys\n", "\n", "#Result\n", "for t in range(len(sys.argv)):\n", " i=0\n", " print sys.argv[t] " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "-c\n", "-f\n", "C:\\Users\\Anandi\\.ipython\\profile_default\\security\\kernel-6e851974-75ff-4911-bdf9-e089a03e5741.json\n", "--KernelApp.parent_appname='ipython-notebook'\n", "--interrupt=904\n", "--parent=876\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.15, Page Number: 144

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import sys\n", "\n", "if len(sys.argv)!=3:\n", " print \"usage: add num num\" \n", "else :\n", " #Variable Decleration\n", " a=sys.argv[1]\n", " b=sys.argv[2]\n", " #Result\n", " print a+b\n", " \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "usage: add num num\n" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.16, Page Number: 145

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import string\n", "\n", "#Variable Decleration\n", "i=string.atoi(\"100\")\n", "j=string.atoi(\"100000\")\n", "k=string.atof(\"-0.123\")\n", "\n", "#Result\n", "print i,\" \",j,\" \",k" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "100 100000 -0.123\n" ] } ], "prompt_number": 13 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.17, Page Number: 147

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable Decleration\n", "i=abs(-10)\n", "\n", "#Result\n", "print abs(-23)\n", "abs(100)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "23\n" ] }, { "metadata": {}, "output_type": "pyout", "prompt_number": 5, "text": [ "100" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.18, Page Number: 148

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Return index of substring or -1 if not found.\n", "def find_substr(sub,str):\n", " l=str.find(sub)\n", " return l\n", "\n", "#Variable decleration;Calling the function\n", "index=find_substr(\"three\",\"one two three four\")\n", "\n", "#Result\n", "print \"Index of three is \",index" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Index of three is 8\n" ] } ], "prompt_number": 6 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.19, Page Number: 149

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "import sys\n", "\n", "def print_vertical(str):\n", " l=len(str)\n", " for i in range(l):\n", " print str[i],\n", " \n", "print_vertical(sys.argv[1])\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "- f\n" ] } ], "prompt_number": 14 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.20, Page Number: 150

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Return position of substring\n", "def find_substr(sub,str):\n", " return str.find(sub)\n", "\n", "#Variable declaration\n", "s=\"one two three four\"\n", "\n", "substr = find_substr(\"three\",s)\n", "\n", "#Result\n", "print \"substring found:\",s[substr:]\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "substring found: three four\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.21, Page Number: 154

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Recursive version\n", "def factr(n):\n", " if n==1:\n", " return 1\n", " answer=factr(n-1)*n\n", " return answer\n", "\n", "#Iterative version\n", "def fact(n):\n", " answer=1\n", " for t in range(n):\n", " answer=answer*(t+1)\n", " return answer\n", "\n", "#Using recursion version\n", "print \"4 factorial is \",factr(4)\n", "\n", "#Using iterative version\n", "print \"4 factorial is \",fact(4)\n", "\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "4 factorial is 24\n", "4 factorial is 24\n" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "metadata": {}, "source": [ "

Example 7.22, Page Number: 155

" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Reversing a string\n", "def reverse(s):\n", " r = \"\"\n", " for c in s:\n", " r=c+r\n", " print r\n", " \n", "#VariabDecleration \n", "str=\"this is a test\"\n", "\n", "#Calling function\n", "reverse(str)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "tset a si siht\n" ] } ], "prompt_number": 9 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }