{ "metadata": { "name": "", "signature": "sha256:218fbe19da172953280529e0559355d55a34bf2741e9ecd127042579a2a52e47" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 16: Managing Input/Output file" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "example 16.1, page no. 300" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "fr = open(\"input.txt\", \"r\")\n", "fw = open(\"output.txt\", \"w\")\n", "my_str = fr.readline()\n", "\n", "for letter in my_str:\n", " fw.write(letter) \n", "#close a file\n", "fr.close()\n", "fw.close()" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.2, page no. 303" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "fw = open(\"cities.txt\", \"w\")\n", "cities = ['Delhi\\n','Madras\\n','London\\n'];\n", "count = len(cities)\n", "for city in cities:\n", " fw.write(city) \n", "fw.close()\n", "fr = open(\"cities.txt\", \"r\")\n", "for line in fr.readlines():\n", " print line," ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Delhi\n", "Madras\n", "London\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.3 is done using CLI which is not possible in IPython Notebook" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.4, page no. 305" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\"\"\"\n", "there is no bytes stream in Python. We will use normal file operations to copy from one file to another\n", "\"\"\"\n", "\n", "fr = open(\"in.txt\", \"r\")\n", "fw = open(\"out.txt\", \"w\")\n", "for line in fr.readlines():\n", " fw.write(line) \n", "fr.close()\n", "fw.close()\n", "\n", "fw = open(\"out.txt\", \"r\")\n", "for line in fw.readlines():\n", " print line" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Java programming for internet.\n", "\n", "Javascript for webpage develpoment.\n", "\n", "Perl for server side scripting.\n", "\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.5, page no. 307" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\"\"\"\n", "Note: In Python you can store data in file only as string.\n", "\"\"\"\n", "\n", "fos = open(\"prim.dat\", \"w\")\n", "fos.write(str(1999)+'\\n')\n", "fos.write(str(375.85)+'\\n')\n", "fos.write(str(False)+'\\n')\n", "fos.write(\"x\"+'\\n')\n", "fos.close()\n", "\n", "fis = open(\"prim.dat\", \"r\")\n", "for line in fis.readlines():\n", " print line\n", "fis.close()" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "1999\n", "\n", "375.85\n", "\n", "False\n", "\n", "x\n", "\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.6, page no. 308" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from random import *\n", "\n", "dos = open(\"rand.dat\", \"w\")\n", "try:\n", " for i in range(20):\n", " dos.write(str(randint(0,100))+'\\n')\n", "except IOError:\n", " print IOError.message\n", "finally:\n", " dos.close()\n", "\n", "dis = open(\"rand.dat\", \"r\")\n", "# Note: random numbers are generated so output will differ from that given in the textbook.\n", "for line in dis.readlines():\n", " print line," ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "92\n", "49\n", "68\n", "67\n", "71\n", "25\n", "85\n", "53\n", "10\n", "87\n", "15\n", "5\n", "33\n", "30\n", "72\n", "52\n", "80\n", "85\n", "36\n", "84\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.7, page no. 310" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "file1 = open(\"file1.txt\", \"r\")\n", "file2 = open(\"file2.txt\", \"r\")\n", "file3 = open(\"file3.txt\", \"a\")\n", "\n", "for line in file1.readlines():\n", " file3.write(line)\n", "for line in file2.readlines():\n", " file3.write(line)\n", " \n", "file1.close()\n", "file2.close()\n", "file3.close()" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.8, page no. 312" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "fp = open(\"random.dat\", \"w+\")\n", "fp.write(\"x\\n\")\n", "fp.write(str(555)+'\\n')\n", "fp.write(str(3.1412)+'\\n')\n", "fp.seek(0)\n", "print fp.readline()\n", "print fp.readline()\n", "print fp.readline()\n", "fp.seek(2)\n", "print fp.readline()\n", "fp.seek(fp.tell()+len(fp.readline()))\n", "fp.write(\"False\\n\")\n", "fp.seek(13)\n", "print fp.readline()\n", "fp.close()" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "x\n", "\n", "555\n", "\n", "3.1412\n", "\n", "555\n", "\n", "False\n", "\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.9, page no. 314" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "fp = open(\"cities.txt\", \"a\")\n", "fp.write(\"Mumbai\\n\")\n", "fp.close()" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 85 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 16.10, page no. 315" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "dos = open(\"invent.dat\", \"w\")\n", "dos.write(raw_input(\"Enter code number: \")+'\\n')\n", "dos.write(raw_input(\"Enter number of items: \")+'\\n')\n", "dos.write(raw_input(\"Enter cost: \")+'\\n')\n", "dos.close()\n", "dis = open(\"invent.dat\", \"r\")\n", "codeNumber = int(dis.readline())\n", "totalItems = int(dis.readline())\n", "itemCost = int(dis.readline())\n", "totalCost = totalItems*itemCost\n", "dis.close()\n", "\n", "print \"Code Number: \", codeNumber\n", "print \"Item Cost: \", itemCost\n", "print \"Total Items: \", totalItems\n", "print \"Total Cost: \", totalCost" ], "language": "python", "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "stream": "stdout", "text": [ "Enter code number: 1001\n" ] }, { "name": "stdout", "output_type": "stream", "stream": "stdout", "text": [ "Enter number of items: 193\n" ] }, { "name": "stdout", "output_type": "stream", "stream": "stdout", "text": [ "Enter cost: 452\n" ] }, { "output_type": "stream", "stream": "stdout", "text": [ "Code Number: 1001\n", "Item Cost: 452\n", "Total Items: 193\n", "Total Cost: 87236\n" ] } ], "prompt_number": 91 } ], "metadata": {} } ] }