{
 "metadata": {
  "name": ""
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Aside"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Formula for the area of a polygon whose vertices are listed in counter-clockwise direction $(x_0, y_0), (x_1, y_1), \\dotsc, (x_n, y_n)$ is\n",
      "\n",
      "\\begin{equation}\n",
      "\\frac{1}{2} (\\det\\begin{pmatrix}x_0 & x_1 \\\\ y_0 & y_1\\end{pmatrix} + \\dotsb + \\det\\begin{pmatrix}x_{n-1} & x_n \\\\ y_{n-1} & y_n\\end{pmatrix} + \\det \\begin{pmatrix}x_n & x_0 \\\\y_n & y_0\\end{pmatrix})\n",
      "\\end{equation}"
     ]
    },
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Class heierachy"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class NameScore :\n",
      "    \"\"\"Stores names and scores\n",
      "    Attributes : \n",
      "        l : list of names and scores\n",
      "    Methods :\n",
      "        add(name, score)\n",
      "        find_score(name)\n",
      "    \"\"\"\n",
      "    \n",
      "    def __init__(self) :\n",
      "        self.l = []\n",
      "        \n",
      "    def add(self, name, score) :\n",
      "        self.l.append((name, score))\n",
      "        \n",
      "    def find_score(self, name) :\n",
      "        lst = []\n",
      "        for (n, s) in self.l :\n",
      "            if n == name :\n",
      "                lst.append(s)\n",
      "        return lst\n",
      "    \n",
      "    def __str__(self) :\n",
      "        return str(self.l)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "if __name__ == '__main__' :\n",
      "    print \"Testing NameScore\"\n",
      "    ns = NameScore()\n",
      "    ns.add(\"Jack\", 10)\n",
      "    ns.add(\"Jill\", 7)\n",
      "    print ns\n",
      "    print ns.find_score(\"Jack\")\n",
      "    print ns.find_score(\"Ellie\")"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Testing NameScore\n",
        "[('Jack', 10), ('Jill', 7)]\n",
        "[10]\n",
        "[]\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Class inheritence"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class Exam(NameScore) :\n",
      "    def average(self) :\n",
      "        no_of_students = len(self.l)\n",
      "        total = 0.0\n",
      "        for nspair in self.l :\n",
      "            total += nspair[1]\n",
      "        return total / no_of_students"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "e = Exam()\n",
      "print e\n",
      "e.add(\"Moo\", 45)\n",
      "e.add(\"Blah\", 20)\n",
      "print e\n",
      "print e.average()\n",
      "print e.find_score('Moo')"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[]\n",
        "[('Moo', 45), ('Blah', 20)]\n",
        "32.5\n",
        "[45]\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class Games(NameScore) :\n",
      "    def maxscore(self) :\n",
      "        m = 0\n",
      "        for ns in self.l :\n",
      "            m = max(m, ns[1])\n",
      "        return m\n",
      "    \n",
      "    def lst_of_winners(self) :\n",
      "        m = self.maxscore()\n",
      "        lstw = []\n",
      "        for ns in self.l :\n",
      "            if ns[1] == m :\n",
      "                lstw.append(ns[0])\n",
      "        return lstw"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "g = Games()\n",
      "g.add(\"Alpha\", 50)\n",
      "g.add(\"Beta\", 60)\n",
      "g.add(\"Gamma\", 0)\n",
      "g.add(\"Delta\", 60)\n",
      "print g\n",
      "print g.lst_of_winners()"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[('Alpha', 50), ('Beta', 60), ('Gamma', 0), ('Delta', 60)]\n",
        "['Beta', 'Delta']\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class TotalScore(Games) :\n",
      "    def __call__(self) :\n",
      "        total = 0.0\n",
      "        for ns in self.l :\n",
      "            total += ns[1]\n",
      "        return total"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "t = TotalScore()\n",
      "t.add(\"a\", 2)\n",
      "t.add(\"b\", 4)\n",
      "print t()"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "6.0\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class Test :\n",
      "    \n",
      "    def __init__(self) :\n",
      "        self.t = TotalScore()\n",
      " \n",
      "    def add(self, name, score) :\n",
      "        self.t.add(name, score)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 9
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "test = Test()\n",
      "test.add('a', 23)\n",
      "test.add('b', 43)\n",
      "print test.t\n",
      "print test.t.l"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "[('a', 23), ('b', 43)]\n",
        "[('a', 23), ('b', 43)]\n"
       ]
      }
     ],
     "prompt_number": 11
    }
   ],
   "metadata": {}
  }
 ]
}