exception.ipynb

{
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    "|Exception | A base class for most error types|\n",
    "|------------------|---------------------------------------|\n",
    "|AttributeError | Raised by syntax obj.foo, if obj has no member named foo|\n",
    "|EOFError | Raised if “end of file” reached for console or file input|\n",
    "|IOError | Raised upon failure of I/O operation (e.g., opening file)|\n",
    "|IndexError | Raised if index to sequence is out of bounds|\n",
    "|KeyError | Raised if nonexistent key requested for set or dictionary|\n",
    "|KeyboardInterrupt | Raised if user types ctrl-C while program is executing|\n",
    "|NameError | Raised if nonexistent identifier used|\n",
    "|StopIteration | Raised by next(iterator) if no element; see Section 1.8|\n",
    "|TypeError | Raised when wrong type of parameter is sent to a function|\n",
    "|ValueError | Raised when parameter has invalid value (e.g., sqrt(−5))|"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "def div():\n",
    "    try:\n",
    "        numer, denom = map(int, input(\"Enter a numerator, denominator: \").strip().split())\n",
    "        print(f\"The fraction ratio is {numer / denom}\")\n",
    "\n",
    "    except Exception as error:\n",
    "        print(\"The Error is\", error)\n",
    "    else:\n",
    "        print(\"The operation done Successfully.\")\n",
    "    finally:\n",
    "        print(\"The Mission Done.\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Enter a numerator, denominator: 8 2\n",
      "The fraction ratio is 4.0\n",
      "The operation done Successfully.\n",
      "The Mission Done.\n"
     ]
    }
   ],
   "source": [
    "div()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Enter a numerator, denominator: 8 0\n",
      "The Error is division by zero\n",
      "The Mission Done.\n"
     ]
    }
   ],
   "source": [
    "div()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Enter a numerator, denominator: 8 a\n",
      "The Error is invalid literal for int() with base 10: 'a'\n",
      "The Mission Done.\n"
     ]
    }
   ],
   "source": [
    "div()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "def read_file(path):\n",
    "    try:\n",
    "        with open(path, 'r') as file:\n",
    "            print(file.read())\n",
    "    except FileNotFoundError as err:\n",
    "        print(\"The Error is\", err.strerror)\n",
    "        print(\"The program has an error.\")\n",
    "    else:\n",
    "        print(\"The file was read successfully.\")\n",
    "    finally:\n",
    "        print(\"The program executed successfully.\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The Error is No such file or directory\n",
      "The program has an error.\n",
      "The program executed successfully.\n"
     ]
    }
   ],
   "source": [
    "read_file(\"./file.txt\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Raise"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Input: 1 2\n",
      "Output: 0.5\n",
      "Input: 9 4\n",
      "Output: 2.25\n",
      "Input: 90 2\n",
      "Output: 45.0\n",
      "Input: 9 a\n"
     ]
    },
    {
     "ename": "ValueError",
     "evalue": "invalid literal for int() with base 10: 'a'",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mValueError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-7-ce47156ee25e>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[1;32m      5\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mBaseException\u001b[0m \u001b[0;32mas\u001b[0m \u001b[0mError\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      6\u001b[0m         \u001b[0;31m# the raise function crash the program and raise the error\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 7\u001b[0;31m         \u001b[0;32mraise\u001b[0m \u001b[0mError\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;32m<ipython-input-7-ce47156ee25e>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[0;32mwhile\u001b[0m \u001b[0;32mTrue\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      2\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 3\u001b[0;31m         \u001b[0ma\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mb\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mmap\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mint\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0minput\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Input: \"\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mstrip\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0msplit\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m      4\u001b[0m         \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Output:\"\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0ma\u001b[0m \u001b[0;34m/\u001b[0m \u001b[0mb\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      5\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mBaseException\u001b[0m \u001b[0;32mas\u001b[0m \u001b[0mError\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;31mValueError\u001b[0m: invalid literal for int() with base 10: 'a'"
     ]
    }
   ],
   "source": [
    "while True:\n",
    "    try:\n",
    "        a, b = map(int, input(\"Input: \").strip().split())\n",
    "        print(\"Output:\", a / b)\n",
    "    except BaseException as Error:\n",
    "        # the raise function crash the program and raise the error\n",
    "        raise Error"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {
    "scrolled": true
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Input: 9 2\n",
      "Output: 4.5\n",
      "Input: 90 1\n",
      "Output: 90.0\n",
      "Input: 99 1\n",
      "Output: 99.0\n",
      "Input: Done\n"
     ]
    }
   ],
   "source": [
    "DEBUG = True\n",
    "while DEBUG:\n",
    "    try:\n",
    "        inp = input(\"Input: \")\n",
    "        if inp == \"Done\":\n",
    "            DEBUG = False\n",
    "            continue\n",
    "        else:\n",
    "            a, b = list(map(int, inp.split()))\n",
    "            print(\"Output:\", a / b)\n",
    "\n",
    "    except BaseException as Error:\n",
    "        # complete the program\n",
    "        raise('The Error was', Error)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Assertion\n",
    "> **assert** <Condetion>, \"Comment will display as Error if condition is false\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [],
   "source": [
    "import datetime\n",
    "\n",
    "def year_of_birth(age):\n",
    "    assert age > 0, \"How your age is negative?\"\n",
    "\n",
    "    current_time = datetime.datetime.now().year\n",
    "\n",
    "    return \"your age is %d\" % int(current_time - age)\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'your age is 2000'"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "year_of_birth(20)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "ename": "AssertionError",
     "evalue": "How your age is negative?",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mAssertionError\u001b[0m                            Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-11-ebf9f622de9d>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0myear_of_birth\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0;36m20\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;32m<ipython-input-9-a10f67ed081c>\u001b[0m in \u001b[0;36myear_of_birth\u001b[0;34m(age)\u001b[0m\n\u001b[1;32m      2\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      3\u001b[0m \u001b[0;32mdef\u001b[0m \u001b[0myear_of_birth\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mage\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 4\u001b[0;31m     \u001b[0;32massert\u001b[0m \u001b[0mage\u001b[0m \u001b[0;34m>\u001b[0m \u001b[0;36m0\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m\"How your age is negative?\"\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m      5\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      6\u001b[0m     \u001b[0mcurrent_time\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mdatetime\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mdatetime\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mnow\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0myear\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;31mAssertionError\u001b[0m: How your age is negative?"
     ]
    }
   ],
   "source": [
    "year_of_birth(-20)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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