Python: How to protect PDF file with password PyPDF2

Popular python library PyPDF2 can be used to set password to PDF file. You can do many other things with this library like:

  • Cropping PDF pages
  • Parse PDF documents metadata (title, author, …)
  • Split pages
  • Merge pages
  • Multiple merge of pages
  • Encrypting and decrypting PDF files

Installation of library PyPDF2 is easy:

pip install pypdf2

The official page of the library is:
Home page for the PyPDF2 project

In this post we will use the PyPDF2 to protect a PDF file with a password.

This is the code example:

import PyPDF2 as p,os
output = p.PdfFileWriter()
input_stream = p.PdfFileReader(open("/home/user/Desktop/1.pdf", "rb"))

for i in range(0, input_stream.getNumPages()):
    output.addPage(input_stream.getPage(i))

outputstream = open("/home/user/Desktop/2.pdf", "wb")

output.encrypt("mypass", use_128bit=True)
output.write(outputstream)
outputstream.close()

The method which is used is encrypt. Below you can find it's header and the documentation:

    def encrypt(self, user_pwd, owner_pwd = None, use_128bit = True):
        """
        Encrypt this PDF file with the PDF Standard encryption handler.

        :param str user_pwd: The "user password", which allows for opening
            and reading the PDF file with the restrictions provided.
        :param str owner_pwd: The "owner password", which allows for
            opening the PDF files without any restrictions.  By default,
            the owner password is the same as the user password.
        :param bool use_128bit: flag as to whether to use 128bit
            encryption.  When false, 40bit encryption will be used.  By default,
            this flag is on.
        """

user_pwd – The "user password", which allows for opening
and reading the PDF file with the restrictions provided.
owner_pwd – he "owner password", which allows for
opening the PDF files without any restrictions. By default,
the owner password is the same as the user password.
use_128bit – Decides which encryption to use128bit or 40bit.

You can control the pages in the output document like starting from page X:

for i in range(1, input_stream.getNumPages()):
    output.addPage(input_stream.getPage(i))

or removing some of the last pages by:

for i in range(0, input_stream.getNumPages() - 1):
    output.addPage(input_stream.getPage(i))

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