Documentos_PDF.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Trabalhando com documentos PDF\n",
    "\n",
    "* PDF = *Portable Document Format*\n",
    "\n",
    "---\n",
    "\n",
    "**Desafios**:\n",
    "\n",
    "* Trabalhar com arquivos binários mais complexos que os arquivos em formato texto simples;\n",
    "\n",
    "\n",
    "* Além do texto, esses arquivos armazenam diversas informações sobre fonte, cor e *layout*.\n",
    "\n",
    "---\n",
    "\n",
    "**Objetivos**:\n",
    "\n",
    "* Ler conteúdo textual dos PDFs;\n",
    "\n",
    "\n",
    "* Compor novos PDFs a partir de documentos existentes."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 1. Importando as bibliotecas necessárias"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import PyPDF2"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 2. Extraindo texto de PDFs\n",
    "\n",
    "#### 2.1. Lendo o arquivo para a extração de informações"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "pdfFileObj = open('data/meetingminutes.pdf', 'rb')\n",
    "pdfReader = PyPDF2.PdfFileReader(pdfFileObj)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 2.2 Verificando o número de páginas"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "19"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pdfReader.numPages"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 2.3. Extraindo o texto da primeira página\n",
    "\n",
    "* `getPage(0)` cria um objeto `Page` referente a primeira página do arquivo PDF.\n",
    "\n",
    "\n",
    "* Obs.: o **PyPDF2** utiliza um índice baseado em zero para obter as páginas."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'OOFFFFIICCIIAALL  BBOOAARRDD  MMIINNUUTTEESS   Meeting of \\nMarch 7\\n, 2014\\n        \\n     The Board of Elementary and Secondary Education shall provide leadership and \\ncreate policies for education that expand opportunities for children, empower \\nfamilies and communities, and advance Louisiana in an increasingly \\ncompetitive glob\\nal market.\\n BOARD \\n of ELEMENTARY\\n and \\n SECONDARY\\n EDUCATION\\n  '"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pageObj = pdfReader.getPage(0)\n",
    "pageObj.extractText()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 3. Descriptografando PDFs\n",
    "\n",
    "* Obs.: a senha do PDF utilizado neste exemplo é **rosebud**.\n",
    "\n",
    "#### 3.1. Lendo o arquivo para a extração de informações"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "pdfFileObj = open('data/encrypted.pdf', 'rb')\n",
    "pdfReader = PyPDF2.PdfFileReader(pdfFileObj)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 3.2. Verificando se o arquivo está criptografado"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pdfReader.isEncrypted"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 3.3. Tentando extrair informações do arquivo criptografado\n",
    "\n",
    "* Qualquer tentativa de chamar um método que leia o arquivo antes que ele seja descriptografado com a senha correta resultará em **erro**."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "ename": "PdfReadError",
     "evalue": "file has not been decrypted",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mPdfReadError\u001b[0m                              Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-7-dbdbde728831>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mpdfReader\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetPage\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;36m0\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;32m~/Dropbox/PyLadies-Minicurso-Automatizando_Tarefas/myenv/lib/python3.6/site-packages/PyPDF2/pdf.py\u001b[0m in \u001b[0;36mgetPage\u001b[0;34m(self, pageNumber)\u001b[0m\n\u001b[1;32m   1174\u001b[0m         \u001b[0;31m#assert not self.trailer.has_key(\"/Encrypt\")\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1175\u001b[0m         \u001b[0;32mif\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mflattenedPages\u001b[0m \u001b[0;34m==\u001b[0m \u001b[0;32mNone\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 1176\u001b[0;31m             \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_flatten\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   1177\u001b[0m         \u001b[0;32mreturn\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mflattenedPages\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0mpageNumber\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1178\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;32m~/Dropbox/PyLadies-Minicurso-Automatizando_Tarefas/myenv/lib/python3.6/site-packages/PyPDF2/pdf.py\u001b[0m in \u001b[0;36m_flatten\u001b[0;34m(self, pages, inherit, indirectRef)\u001b[0m\n\u001b[1;32m   1503\u001b[0m         \u001b[0;32mif\u001b[0m \u001b[0mpages\u001b[0m \u001b[0;34m==\u001b[0m \u001b[0;32mNone\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1504\u001b[0m             \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mflattenedPages\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-> 1505\u001b[0;31m             \u001b[0mcatalog\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mtrailer\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m\"/Root\"\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetObject\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   1506\u001b[0m             \u001b[0mpages\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mcatalog\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m\"/Pages\"\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetObject\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1507\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;32m~/Dropbox/PyLadies-Minicurso-Automatizando_Tarefas/myenv/lib/python3.6/site-packages/PyPDF2/generic.py\u001b[0m in \u001b[0;36m__getitem__\u001b[0;34m(self, key)\u001b[0m\n\u001b[1;32m    514\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    515\u001b[0m     \u001b[0;32mdef\u001b[0m \u001b[0m__getitem__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mkey\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 516\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mdict\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m__getitem__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mkey\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetObject\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    517\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    518\u001b[0m     \u001b[0;31m##\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;32m~/Dropbox/PyLadies-Minicurso-Automatizando_Tarefas/myenv/lib/python3.6/site-packages/PyPDF2/generic.py\u001b[0m in \u001b[0;36mgetObject\u001b[0;34m(self)\u001b[0m\n\u001b[1;32m    176\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    177\u001b[0m     \u001b[0;32mdef\u001b[0m \u001b[0mgetObject\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 178\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mpdf\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetObject\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetObject\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    179\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    180\u001b[0m     \u001b[0;32mdef\u001b[0m \u001b[0m__repr__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;32m~/Dropbox/PyLadies-Minicurso-Automatizando_Tarefas/myenv/lib/python3.6/site-packages/PyPDF2/pdf.py\u001b[0m in \u001b[0;36mgetObject\u001b[0;34m(self, indirectReference)\u001b[0m\n\u001b[1;32m   1615\u001b[0m                 \u001b[0;31m# if we don't have the encryption key:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1616\u001b[0m                 \u001b[0;32mif\u001b[0m \u001b[0;32mnot\u001b[0m \u001b[0mhasattr\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'_decryption_key'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 1617\u001b[0;31m                     \u001b[0;32mraise\u001b[0m \u001b[0mutils\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mPdfReadError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"file has not been decrypted\"\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m   1618\u001b[0m                 \u001b[0;31m# otherwise, decrypt here...\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1619\u001b[0m                 \u001b[0;32mimport\u001b[0m \u001b[0mstruct\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;31mPdfReadError\u001b[0m: file has not been decrypted"
     ]
    }
   ],
   "source": [
    "pdfReader.getPage(0)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 3.4. Repetindo a operação após descriptografar\n",
    "\n",
    "* Se a senha incorreta for especificada, o método `decrypt()` retornará `0`."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "1"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pdfReader.decrypt('rosebud')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "ename": "IndexError",
     "evalue": "list index out of range",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-9-035b8734cb5d>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mpageObj\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mpdfReader\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetPage\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;36m0\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;32m~/Dropbox/PyLadies-Minicurso-Automatizando_Tarefas/myenv/lib/python3.6/site-packages/PyPDF2/pdf.py\u001b[0m in \u001b[0;36mgetPage\u001b[0;34m(self, pageNumber)\u001b[0m\n\u001b[1;32m   1175\u001b[0m         \u001b[0;32mif\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mflattenedPages\u001b[0m \u001b[0;34m==\u001b[0m \u001b[0;32mNone\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1176\u001b[0m             \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_flatten\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 1177\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mflattenedPages\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0mpageNumber\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m   1178\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1179\u001b[0m     namedDestinations = property(lambda self:\n",
      "\u001b[0;31mIndexError\u001b[0m: list index out of range"
     ]
    }
   ],
   "source": [
    "pageObj = pdfReader.getPage(0)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "* Obs.: utilizar `getPage()` antes de `decrypt()` ocasiona erro na utilização de `getPage()` após o `decrypt()`."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 3.5. Forma correta de realizar a operação"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [],
   "source": [
    "pdfFileObj = open('data/encrypted.pdf', 'rb')\n",
    "pdfReader = PyPDF2.PdfFileReader(pdfFileObj)\n",
    "\n",
    "if pdfReader.isEncrypted:\n",
    "    pdfReader.decrypt('rosebud')\n",
    "    pageObj = pdfReader.getPage(0)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "* Obs: o método `decrypt()` descriptografa somente o objeto `PdfFileReader`, e não o arquivo PDF propriamente dito."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 4. Criando PDFs\n",
    "\n",
    "* Agora vamos utilizar o `PdfFileWriter`.\n",
    "\n",
    "\n",
    "* O `PyPDF2` não pode escrever qualquer texto em um PDF. As capacidades de escrita de PDF do `PyPDF2` estão limitadas a:\n",
    "    * Copiar páginas de outros PDFs;\n",
    "    * Fazer rotação de páginas;\n",
    "    * Sobrepor páginas;\n",
    "    * Criptografar arquivos.\n",
    "    \n",
    "    \n",
    "* O `PyPDF2` não permite editar diretamente um PDF. Em vez disso, você deverá criar um novo PDF e então copiar o conteúdo de um documento existente.\n",
    "\n",
    "\n",
    "* Para criar o arquivo PDF chame o método `write()` de `PdfFileWriter`.\n",
    "\n",
    "#### 4.1. Copiando páginas"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [],
   "source": [
    "pdf1File = open('data/meetingminutes.pdf', 'rb')\n",
    "pdf2File = open('data/meetingminutes.pdf', 'rb')\n",
    "\n",
    "pdf1Reader = PyPDF2.PdfFileReader(pdf1File)\n",
    "pdf2Reader = PyPDF2.PdfFileReader(pdf2File)\n",
    "\n",
    "pdfWriter = PyPDF2.PdfFileWriter()\n",
    "\n",
    "for pageNum in range(pdf1Reader.numPages):\n",
    "    pageObj = pdf1Reader.getPage(pageNum)\n",
    "    pdfWriter.addPage(pageObj)\n",
    "    \n",
    "    \n",
    "for pageNum in range(pdf2Reader.numPages):\n",
    "    pageObj = pdf2Reader.getPage(pageNum)\n",
    "    pdfWriter.addPage(pageObj)\n",
    "    \n",
    "pdfOutputFile = open('data/combinedminutes.pdf', 'wb')\n",
    "pdfWriter.write(pdfOutputFile)\n",
    "\n",
    "pdfOutputFile.close()\n",
    "pdf1File.close()\n",
    "pdf2File.close()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "* Obs.: o método `addPage()` adicionará páginas somente no final do PDF."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 4.2. Rotação de páginas\n",
    "\n",
    "* O PDF resultante terá uma página girada em 90 graus no sentido horário."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [],
   "source": [
    "minutesFile = open('data/meetingminutes.pdf', 'rb')\n",
    "pdf1Reader = PyPDF2.PdfFileReader(minutesFile)\n",
    "\n",
    "page = pdf1Reader.getPage(0)\n",
    "page.rotateClockwise(90) # Aceita os valores 90, 180 e 270\n",
    "\n",
    "pdfWriter = PyPDF2.PdfFileWriter()\n",
    "pdfWriter.addPage(page)\n",
    "\n",
    "resultPdfFile = open('data/rotatedPage.pdf', 'wb')\n",
    "pdfWriter.write(resultPdfFile)\n",
    "\n",
    "resultPdfFile.close()\n",
    "minutesFile.close()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 4.3. Sobrepondo páginas\n",
    "\n",
    "* Em Python, é fácil adicionar marcas-d'água em diversos arquivos e somente nas páginas especificadas pelo seu programa.\n",
    "\n",
    "\n",
    "* Utilizaremos o método `mergePage()`."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [],
   "source": [
    "minutesFile = open('data/meetingminutes.pdf', 'rb')\n",
    "pdfReader = PyPDF2.PdfFileReader(minutesFile)\n",
    "\n",
    "minutesFirstPage = pdfReader.getPage(0)\n",
    "\n",
    "pdfWatermarkReader = PyPDF2.PdfFileReader(open('data/watermark.pdf', 'rb'))\n",
    "\n",
    "minutesFirstPage.mergePage(pdfWatermarkReader.getPage(0))\n",
    "\n",
    "pdfWriter = PyPDF2.PdfFileWriter()\n",
    "pdfWriter.addPage(minutesFirstPage)\n",
    "\n",
    "for pageNum in range(1, pdfReader.numPages):\n",
    "    pageObj = pdfReader.getPage(pageNum)\n",
    "    pdfWriter.addPage(pageObj)\n",
    "    \n",
    "resultPdfFile = open('data/watermarkedCover.pdf', 'wb')\n",
    "pdfWriter.write(resultPdfFile)\n",
    "\n",
    "minutesFile.close()\n",
    "resultPdfFile.close()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 4.4. Criptografando PDFs\n",
    "\n",
    "* Antes de chamar o método `write()` para salvar os dados em um arquivo, chame o método `encrypt()` e passe uma string de senha a ele."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [],
   "source": [
    "pdfFile = open('data/meetingminutes.pdf', 'rb')\n",
    "pdfReader = PyPDF2.PdfFileReader(pdfFile)\n",
    "\n",
    "pdfWriter = PyPDF2.PdfFileWriter()\n",
    "\n",
    "for pageNum in range(pdfReader.numPages):\n",
    "    pdfWriter.addPage(pdfReader.getPage(pageNum))\n",
    "    \n",
    "pdfWriter.encrypt('swordfish')\n",
    "\n",
    "resultPdf = open('data/encryptedminutes.pdf', 'wb')\n",
    "pdfWriter.write(resultPdf)\n",
    "\n",
    "resultPdf.close()"
   ]
  }
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