{
 "metadata": {
  "name": "9932_02_01"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Chapter 2, example 1\n",
      "====================\n",
      "\n",
      "In this example, we show how to use IPython to perform common system actions such as downloading a Zip file, extracting it in a new folder, etc. Specifically, we download some social data about anonymous volunteer Facebook users.\n",
      "\n",
      "The data is freely available on [Stanford's SNAP project](http://snap.stanford.edu/data/)."
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "We begin by importing native modules used to download and extract compressed files."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import urllib2, zipfile"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "url = 'http://ipython.rossant.net/'"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "filename = 'facebook.zip'"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "We download the file in memory with `urllib2.urlopen`."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "downloaded = urllib2.urlopen(url + filename)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 4
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Now, we create a new folder named `data` and we save the Zip file in it."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "folder = 'data'"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "mkdir $folder"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 6
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "cd $folder"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "chapter2\\data\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "with open(filename, 'wb') as f:\n",
      "    f.write(downloaded.read())"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 8
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "We use the `zipfile` module to extract the Zip file in the `data` folder."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "with zipfile.ZipFile(filename) as zip:\n",
      "    zip.extractall('.')"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 9
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Common system file commands such as `ls` just work in IPython, even on Windows systems!"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "ls"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "facebook.zip\n",
        ""
       ]
      }
     ],
     "prompt_number": 10
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "cd facebook"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "chapter2\\data\\facebook\n"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "ls"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "0.circles\n",
        "0.edges\n",
        "107.circles\n",
        "107.edges\n",
        "1684.circles\n",
        "1684.edges\n",
        "1912.circles\n",
        "1912.edges\n",
        "3437.circles\n",
        "3437.edges\n",
        "348.circles\n",
        "348.edges\n",
        "3980.circles\n",
        "3980.edges\n",
        "414.circles\n",
        "414.edges\n",
        "686.circles\n",
        "686.edges\n",
        "698.circles\n",
        "698.edges\n",
        ""
       ]
      }
     ],
     "prompt_number": 12
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "We save the `data/facebook/` directory as an alias for later. We will be able to enter this directory just with `cd fbdata`."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%bookmark fbdata"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 13
    }
   ],
   "metadata": {}
  }
 ]
}