IPython notebook demonstrating how properties are different in new-style and old-style py 2.x classes

old-style class property weirdness.ipynb

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   "cells": [
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Note that this is run in py2.7"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class A:\n",
      "    def __init__(self,a ):\n",
      "        self.a = a\n",
      "        \n",
      "class B(A):\n",
      "    @property\n",
      "    def a(self):\n",
      "        return self._a + 100\n",
      "    @a.setter\n",
      "    def a(self, val):\n",
      "        self._a = val\n",
      "        "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "o=A(1)\n",
      "o.a"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 5,
       "text": [
        "1"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "o=B(2)\n",
      "o.a"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 6,
       "text": [
        "2"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "class A(object):\n",
      "    def __init__(self,a ):\n",
      "        self.a = a\n",
      "        \n",
      "class B(A):\n",
      "    @property\n",
      "    def a(self):\n",
      "        return self._a + 100\n",
      "    @a.setter\n",
      "    def a(self, val):\n",
      "        self._a = val"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "o=A(1)\n",
      "o.a"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 8,
       "text": [
        "1"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "o=B(2)\n",
      "o.a"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 9,
       "text": [
        "102"
       ]
      }
     ],
     "prompt_number": 9
    }
   ],
   "metadata": {}
  }
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