This is short example of using some features of the debug magic in IPython

Debugging Example.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "def bad_fun(x):\n",
    "    \"This is a functionwritten to test the debug magic\"\n",
    "    y = x^2 +3*x+4\n",
    "    if x ==3 and y!=22:\n",
    "        raise(RuntimeError(\"The symbol ^ is not a power symbol but rather a bit shift.\"))\n",
    "    try:\n",
    "        z = x/0\n",
    "    except ZeroDivisionError:\n",
    "        print(\"Don't divide by zero\")\n",
    "    print(\"{x}\".format(x=x))\n",
    "    print(y)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "ename": "RuntimeError",
     "evalue": "The symbol ^ is not a power symbol but rather a bit shift.",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
      "\u001b[1;32m<ipython-input-2-09ec772c4271>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mbad_fun\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;36m3\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[1;32m<ipython-input-1-1f18c9d5c240>\u001b[0m in \u001b[0;36mbad_fun\u001b[1;34m(x)\u001b[0m\n\u001b[0;32m      3\u001b[0m     \u001b[0my\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mx\u001b[0m\u001b[1;33m^\u001b[0m\u001b[1;36m2\u001b[0m \u001b[1;33m+\u001b[0m\u001b[1;36m3\u001b[0m\u001b[1;33m*\u001b[0m\u001b[0mx\u001b[0m\u001b[1;33m+\u001b[0m\u001b[1;36m4\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m      4\u001b[0m     \u001b[1;32mif\u001b[0m \u001b[0mx\u001b[0m \u001b[1;33m==\u001b[0m\u001b[1;36m3\u001b[0m \u001b[1;32mand\u001b[0m \u001b[0my\u001b[0m\u001b[1;33m!=\u001b[0m\u001b[1;36m22\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 5\u001b[1;33m         \u001b[1;32mraise\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mRuntimeError\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"The symbol ^ is not a power symbol but rather a bit shift.\"\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m      6\u001b[0m     \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m      7\u001b[0m         \u001b[0mz\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mx\u001b[0m\u001b[1;33m/\u001b[0m\u001b[1;36m0\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;31mRuntimeError\u001b[0m: The symbol ^ is not a power symbol but rather a bit shift."
     ]
    }
   ],
   "source": [
    "bad_fun(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "> \u001b[1;32m<ipython-input-1-1f18c9d5c240>\u001b[0m(5)\u001b[0;36mbad_fun\u001b[1;34m()\u001b[0m\n",
      "\u001b[1;32m      4 \u001b[1;33m    \u001b[1;32mif\u001b[0m \u001b[0mx\u001b[0m \u001b[1;33m==\u001b[0m\u001b[1;36m3\u001b[0m \u001b[1;32mand\u001b[0m \u001b[0my\u001b[0m\u001b[1;33m!=\u001b[0m\u001b[1;36m22\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[0m\u001b[1;32m----> 5 \u001b[1;33m        \u001b[1;32mraise\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mRuntimeError\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"The symbol ^ is not a power symbol but rather a bit shift.\"\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[0m\u001b[1;32m      6 \u001b[1;33m    \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[0m\n",
      "ipdb> h\n",
      "\n",
      "Documented commands (type help <topic>):\n",
      "========================================\n",
      "EOF    cl         disable  interact  pdef     quit     source     up    \n",
      "a      clear      display  j         pdoc     r        step       w     \n",
      "alias  commands   down     jump      pfile    restart  tbreak     whatis\n",
      "args   condition  enable   ll        pinfo    return   u          where \n",
      "b      cont       exit     longlist  pinfo2   retval   unalias  \n",
      "break  continue   h        n         pp       run      undisplay\n",
      "bt     d          help     next      psource  rv       unt      \n",
      "c      debug      ignore   p         q        s        until    \n",
      "\n",
      "Miscellaneous help topics:\n",
      "==========================\n",
      "pdb  exec\n",
      "\n",
      "Undocumented commands:\n",
      "======================\n",
      "l  list\n",
      "\n",
      "ipdb> a\n",
      "x = 3\n",
      "ipdb> p y\n",
      "12\n",
      "ipdb> q\n"
     ]
    }
   ],
   "source": [
    "%debug"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.4.0"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 0
}