{
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# <font color='blue'>Data Science Academy - Python Fundamentos - Capítulo 5</font>\n",
    "## Download: http://github.com/dsacademybr"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Métodos Especiais"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "# Criando a classe Livro\n",
    "class Livro():\n",
    "    def __init__(self, titulo, autor, paginas):\n",
    "        print (\"Livro criado\")\n",
    "        self.titulo = titulo\n",
    "        self.autor = autor\n",
    "        self.paginas = paginas\n",
    "                \n",
    "    def __str__(self):\n",
    "        return \"Título: %s , autor: %s, páginas: %s \" \\\n",
    "    %(self.titulo, self.autor, self.paginas)\n",
    "\n",
    "    def __len__(self):\n",
    "        return self.paginas\n",
    "    \n",
    "    def len(self):\n",
    "        return print(\"Páginas do livro com método comum: \", self.paginas)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Livro criado\n"
     ]
    }
   ],
   "source": [
    "livro1 = Livro(\"Os Lusíadas\", \"Luis de Camões\", 8816)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Título: Os Lusíadas , autor: Luis de Camões, páginas: 8816 \n"
     ]
    }
   ],
   "source": [
    "# Métodos especiais\n",
    "print(livro1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Título: Os Lusíadas , autor: Luis de Camões, páginas: 8816 '"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "str(livro1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "8816"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "len(livro1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Páginas do livro com método comum:  8816\n"
     ]
    }
   ],
   "source": [
    "livro1.len()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "# Ao executar a função del para remover um atributo, o Python executa:\n",
    "# livro1.__delattr__(\"paginas\")\n",
    "del livro1.paginas"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "False"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "hasattr(livro1, \"paginas\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Fim"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Obrigado - Data Science Academy - <a href=\"http://facebook.com/dsacademybr\">facebook.com/dsacademybr</a>"
   ]
  }
 ],
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