notebooks/unit03/unit03_03.ipynb

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   "source": [
    "This notebook was prepared by Cayetano Benavent, 2016."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Handling exceptions"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "collapsed": true
   },
   "source": [
    "Handling exceptions with TRY-EXCEPT:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "def circlePerim(rad):\n",
    "    return 2 * math.pi * rad"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "An error executing this script because we do not import Math module:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "ename": "NameError",
     "evalue": "name 'math' is not defined",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mNameError\u001b[0m                                 Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-2-c307e3cd6ad6>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mcirclePerim\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"hola\"\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;32m<ipython-input-1-92e3d430b0e3>\u001b[0m in \u001b[0;36mcirclePerim\u001b[0;34m(rad)\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0mcirclePerim\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mrad\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 2\u001b[0;31m     \u001b[0;32mreturn\u001b[0m \u001b[0;36m2\u001b[0m \u001b[0;34m*\u001b[0m \u001b[0mmath\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mpi\u001b[0m \u001b[0;34m*\u001b[0m \u001b[0mrad\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;31mNameError\u001b[0m: name 'math' is not defined"
     ]
    }
   ],
   "source": [
    "circlePerim(\"hola\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "def circlePerim(rad):\n",
    "    try:\n",
    "        return 2 * math.pi * rad\n",
    "    except Exception as error:\n",
    "        print(\"Error: {0}\".format(error))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Error: name 'math' is not defined\n"
     ]
    }
   ],
   "source": [
    "circlePerim(\"hola\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "import math\n",
    "\n",
    "def circlePerim(rad):\n",
    "    try:\n",
    "        return 2 * math.pi * rad\n",
    "    except Exception as error:\n",
    "        print(\"Error: {0}\".format(error))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Error: can't multiply sequence by non-int of type 'float'\n"
     ]
    }
   ],
   "source": [
    "circlePerim(\"hola\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Handling specific errors:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "def circlePerim(rad):\n",
    "    try:\n",
    "        return 2 * math.pi * rad\n",
    "    except TypeError as error:\n",
    "        print(\"Type Error: {0}\".format(error))\n",
    "    except Exception as error:\n",
    "        print(\"Error: {0}\".format(error))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Type Error: can't multiply sequence by non-int of type 'float'\n"
     ]
    }
   ],
   "source": [
    "circlePerim(\"hola\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "FINALLY clause (always is executed):"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "def circlePerim(rad):\n",
    "    try:\n",
    "        return 2 * math.pi * rad\n",
    "    except TypeError as error:\n",
    "        print(\"Type Error: {0}\".format(error))\n",
    "    except Exception as error:\n",
    "        print(\"Error: {0}\".format(error))\n",
    "    finally:\n",
    "        print(\"Finalized execution. Value of radious: {0}\".format(rad))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Type Error: can't multiply sequence by non-int of type 'float'\n",
      "Finalized execution. Value of radious: hola\n"
     ]
    }
   ],
   "source": [
    "circlePerim(\"hola\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Finalized execution. Value of radious: 10\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "62.83185307179586"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "circlePerim(10)"
   ]
  }
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