{
 "metadata": {
  "name": "",
  "signature": "sha256:4c41735fb67bb40797fc8ec99d1c0b5c81a6828d699e86fe05c05b6962ed94db"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 4: Loops"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.1, page no. 139"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "for count in range (1, 11):\n",
      "    print count,\n",
      "print \"\\nAfter the loop count has the value %d.\" %count"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1 2 3 4 5 6 7 8 9 10 \n",
        "After the loop count has the value 10.\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.2, page no. 140"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "print \"**************\"\n",
      "for count in range(1, 9):\n",
      "    print \"*            *\"\n",
      "print \"**************\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "**************\n",
        "*            *\n",
        "*            *\n",
        "*            *\n",
        "*            *\n",
        "*            *\n",
        "*            *\n",
        "*            *\n",
        "*            *\n",
        "**************\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.3, page no. 144"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "sum = 0\n",
      "\n",
      "print \"Enter the number of integers you want to sum: \",\n",
      "count = int(raw_input())\n",
      " \n",
      "for i in range(1, count+1):\n",
      "    sum = sum + i\n",
      " \n",
      "print \"Total of the first %d numbers is %d\" %(count, sum)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the number of integers you want to sum: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Total of the first 10 numbers is 55\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.4, page no. 144"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "sum = 0\n",
      "\n",
      "print \"Enter the number of integers you want to sum: \",\n",
      "count = int(raw_input())\n",
      " \n",
      "for i in range(1, count+1):\n",
      "    sum = sum + i\n",
      " \n",
      "print \"Total of the first %d numbers is %d\" %(count, sum)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the number of integers you want to sum: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Total of the first 10 numbers is 55\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.5, page no. 147"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "sum = 0\n",
      "\n",
      "print \"Enter the number of integers you want to sum: \",\n",
      "count = int(raw_input())\n",
      "for i in range(count, 0, -1):\n",
      "    sum = sum + i\n",
      "print \"Total of the first %d numbers is %d\" %(count, sum)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the number of integers you want to sum: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Total of the first 10 numbers is 55\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.6, page no. 148"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "print \"This program calculates the average of any number of values.\"\n",
      "total = 0\n",
      "count = 0\n",
      "while True: # infinite loop\n",
      "    print \"\\nEnter a value: \",\n",
      "    value = float(raw_input())\n",
      "    total += value\n",
      "    count += 1\n",
      " \n",
      "    print \"Do you want to enter another value? (Y or N): \", \n",
      "    answer = raw_input()\n",
      "    if(answer.lower() == 'n'):\n",
      "        break\n",
      "\n",
      "print \"The average is %.2f\" %(total/count)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "This program calculates the average of any number of values.\n",
        "\n",
        "Enter a value: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Do you want to enter another value? (Y or N): "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "y\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " \n",
        "Enter a value: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "8\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Do you want to enter another value? (Y or N): "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "y\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " \n",
        "Enter a value: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "6\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Do you want to enter another value? (Y or N): "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "n\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " The average is 8.00\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.7, page no. 151"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "import sys\n",
      "\n",
      "chosen = 15\n",
      "guess = 0\n",
      "count = 3\n",
      " \n",
      "print \"This is a guessing game.\"\n",
      "print \"I have chosen a number between 1 and 20 which you must guess.\"\n",
      "\n",
      "for i in range(count, 0, -1):\n",
      "    print \"You have %d tr%s left.\" %(i, (\"y\" if i == 1 else \"ies\"));\n",
      "    print \"\\nEnter a guess: \",\n",
      "    guess = int(raw_input())\n",
      "    if(guess == chosen):\n",
      "        print \"Congratulations. You guessed it!\"\n",
      "        sys.exit()\n",
      "    elif(guess < 1 or guess > 20):\n",
      "        print \"I said the number is between 1 and 20.\"\n",
      "    else:\n",
      "        print \"Sorry, %d is wrong. My number is %s than that.\\n\" %(guess, (\"greater\" if chosen > guess else \"less\"))\n",
      "print \"You have had three tries and failed. The number was %d\" % chosen"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "This is a guessing game.\n",
        "I have chosen a number between 1 and 20 which you must guess.\n",
        "You have 3 tries left.\n",
        "\n",
        "Enter a guess: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "5\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Sorry, 5 is wrong. My number is greater than that.\n",
        "\n",
        "You have 2 tries left.\n",
        "\n",
        "Enter a guess: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "9\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Sorry, 9 is wrong. My number is greater than that.\n",
        "\n",
        "You have 1 try left.\n",
        "\n",
        "Enter a guess: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "14\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Sorry, 14 is wrong. My number is greater than that.\n",
        "\n",
        "You have had three tries and failed. The number was 15\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.7A, page no. 154"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "from random import *\n",
      "\n",
      "guess = 0\n",
      "count = 3\n",
      "limit = 20\n",
      "\n",
      "chosen = 1 + randint(1, limit) #Random int 1 to limit\n",
      " \n",
      "print \"This is a guessing game.\"\n",
      "print \"I have chosen a number between 1 and 20 which you must guess.\"\n",
      "\n",
      "for i in range(count, 0, -1):\n",
      "    print \"You have %d tr%s left.\" %(i, (\"y\" if i == 1 else \"ies\"));\n",
      "    print \"Enter a guess: \",\n",
      "    guess = int(raw_input())\n",
      "    if(guess == chosen):\n",
      "        print \"Congratulations. You guessed it!\"\n",
      "        sys.exit()\n",
      "    elif(guess < 1 or guess > 20):\n",
      "        print \"I said the number is between 1 and 20.\"\n",
      "    else:\n",
      "        print \"Sorry, %d is wrong. My number is %s than that.\\n\" %(guess, (\"greater\" if chosen > guess else \"less\"))\n",
      "print \"You have had three tries and failed. The number was %d\" % chosen"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "This is a guessing game.\n",
        "I have chosen a number between 1 and 20 which you must guess.\n",
        "You have 3 tries left.\n",
        "Enter a guess: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "6\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Sorry, 6 is wrong. My number is greater than that.\n",
        "\n",
        "You have 2 tries left.\n",
        "Enter a guess: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "14\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Sorry, 14 is wrong. My number is greater than that.\n",
        "\n",
        "You have 1 try left.\n",
        "Enter a guess: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "16\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Sorry, 16 is wrong. My number is greater than that.\n",
        "\n",
        "You have had three tries and failed. The number was 20\n"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.8, page no. 158"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "sum = 0\n",
      "i = 1\n",
      "\n",
      "print \"Enter the number of integers you want to sum: \",\n",
      "count = int(raw_input())\n",
      " \n",
      "while(i <= count):\n",
      "    sum += i\n",
      "    i += 1\n",
      " \n",
      "print \"Total of the first %d numbers is %d\" %(count, sum)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the number of integers you want to sum: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Total of the first 10 numbers is 55\n"
       ]
      }
     ],
     "prompt_number": 9
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.9, page no. 161"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "MIN_SIZE = 3;\n",
      " \n",
      "print \"Enter values for the width and height (minimum of %d): \" % MIN_SIZE\n",
      "width = int(raw_input(\"Width: \"))\n",
      "height = int(raw_input(\"Height: \"))\n",
      " \n",
      "if(width < MIN_SIZE):\n",
      "    print \"Width value of %d is too small. Setting it to %d.\" %(width, MIN_SIZE)\n",
      "    width = MIN_SIZE\n",
      "if(height < MIN_SIZE):\n",
      "    print \"Height value of %d is too small. Setting it to %d.\" %(height, MIN_SIZE)\n",
      "    height = MIN_SIZE\n",
      "\n",
      "\n",
      "for i in range(0, width):\n",
      "    print \"*\",\n",
      "print \"\\n\"\n",
      "for j in range(0, height-2):\n",
      "    print \"*\",\n",
      "    for i in range(0, width-2):\n",
      "        print \" \",\n",
      "    print \"*\"\n",
      "\n",
      "print \"\\n\"\n",
      "for i in range(0, width):\n",
      "    print \"*\","
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter values for the width and height (minimum of 3): \n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Width: 24\n"
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Height: 7\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "* * * * * * * * * * * * * * * * * * * * * * * * \n",
        "\n",
        "*                                             *\n",
        "*                                             *\n",
        "*                                             *\n",
        "*                                             *\n",
        "*                                             *\n",
        "\n",
        "\n",
        "* * * * * * * * * * * * * * * * * * * * * * * *\n"
       ]
      }
     ],
     "prompt_number": 17
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.10, page no. 162"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "sum = 0\n",
      "count = 0\n",
      "\n",
      "print \"Enter the number of integers you want to sum: \",\n",
      "count = int(raw_input())\n",
      " \n",
      "for i in range(1, count+1):\n",
      "    sum = 0\n",
      "    for j in range(1, i+1):\n",
      "        sum += j\n",
      "    print \"%d\\t%5d\" %(i, sum)\n",
      "print \"\\n\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the number of integers you want to sum: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " 1\t    1\n",
        "2\t    3\n",
        "3\t    6\n",
        "4\t   10\n",
        "5\t   15\n",
        "6\t   21\n",
        "7\t   28\n",
        "8\t   36\n",
        "9\t   45\n",
        "10\t   55\n",
        "\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 18
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.11, page no. 164"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "\n",
      "print \"Enter the number of integers you want to sum: \",\n",
      "count = int(raw_input())\n",
      "\n",
      "for i in range(1, count+1):\n",
      "    sum = 1\n",
      "    j = 1\n",
      "    print \"1\",\n",
      "    while(j < i):\n",
      "        j += 1\n",
      "        sum += j\n",
      "        print \"+ %d\" % j,\n",
      "    print \"= %d\" % sum\n",
      "print \"\\n\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Enter the number of integers you want to sum: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " 1 = 1\n",
        "1 + 2 = 3\n",
        "1 + 2 + 3 = 6\n",
        "1 + 2 + 3 + 4 = 10\n",
        "1 + 2 + 3 + 4 + 5 = 15\n",
        "1 + 2 + 3 + 4 + 5 + 6 = 21\n",
        "1 + 2 + 3 + 4 + 5 + 6 + 7 = 28\n",
        "1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36\n",
        "1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45\n",
        "1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55\n",
        "\n",
        "\n"
       ]
      }
     ],
     "prompt_number": 19
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Program 4.12, page no. 167"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "rebmun = 0\n",
      "print \"\\nEnter a positive integer: \",\n",
      "number = int(raw_input())\n",
      "temp = number\n",
      "while(temp):\n",
      "    rebmun = 10*rebmun + temp % 10\n",
      "    temp = temp/10\n",
      "\n",
      "print \"The number %d reversed is %d rebmun ehT\" %(number, rebmun)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "\n",
        "Enter a positive integer: "
       ]
      },
      {
       "name": "stdout",
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "7\n"
       ]
      },
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " The number 7 reversed is 7 rebmun ehT\n"
       ]
      }
     ],
     "prompt_number": 20
    }
   ],
   "metadata": {}
  }
 ]
}