{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Online Python Tutor\n",
    "\n",
    "This notebook shows how to create a cell magic for calling Online Python Tutor.\n",
    "\n",
    "First, we define the code to embed the tutor, and register the magic:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "from IPython.display import HTML, display\n",
    "from IPython.core.magic import register_line_cell_magic\n",
    "import urllib\n",
    "\n",
    "@register_line_cell_magic\n",
    "def tutor(line, cell):\n",
    "    code = urllib.urlencode({\"code\": cell})\n",
    "    display(HTML(\"\"\"\n",
    "    <iframe width=\"800\" height=\"500\" frameborder=\"0\"\n",
    "            src=\"http://pythontutor.com/iframe-embed.html#%s&py=2\">\n",
    "    </iframe>\n",
    "    \"\"\" % code))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Next, we write some code:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0 0\n",
      "0 1\n",
      "0 2\n",
      "1 0\n",
      "1 1\n",
      "1 2\n",
      "2 0\n",
      "2 1\n",
      "2 2\n",
      "45\n"
     ]
    }
   ],
   "source": [
    "matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]\n",
    "\n",
    "sum = 0\n",
    "for i in range(len(matrix)):\n",
    "    for j in range(len(matrix[i])):\n",
    "        row = matrix[i]\n",
    "        sum += row[j]\n",
    "        print i, j\n",
    "print sum"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "To see it execute line my line, we simply prefix the cell with our new `%%tutor` cell magic:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "data": {
      "text/html": [
       "\n",
       "    <iframe width=\"800\" height=\"500\" frameborder=\"0\"\n",
       "            src=\"http://pythontutor.com/iframe-embed.html#code=matrix+%3D+%5B%5B1%2C+2%2C+3%5D%2C+%0A++++++++++%5B4%2C+5%2C+6%5D%2C+%0A++++++++++%5B7%2C+8%2C+9%5D%5D%0A%0Asum+%3D+0%0Afor+i+in+range%28len%28matrix%29%29%3A%0A++++for+j+in+range%28len%28matrix%5Bi%5D%29%29%3A%0A++++++++row+%3D+matrix%5Bi%5D%0A++++++++sum+%2B%3D+row%5Bj%5D%0A++++++++print+i%2C+j%0Aprint+sum&py=2\">\n",
       "    </iframe>\n",
       "    "
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "%%tutor\n",
    "matrix = [[1, 2, 3], \n",
    "          [4, 5, 6], \n",
    "          [7, 8, 9]]\n",
    "\n",
    "sum = 0\n",
    "for i in range(len(matrix)):\n",
    "    for j in range(len(matrix[i])):\n",
    "        row = matrix[i]\n",
    "        sum += row[j]\n",
    "        print i, j\n",
    "print sum"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 2",
   "language": "",
   "name": "python2"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 2
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython2",
   "version": "2.7.6"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 0
}