encrypt.py

from PyPDF2 import PdfFileWriter, PdfFileReader

def add_encryption(input_pdf, output_pdf, password):
    pdf_writer = PdfFileWriter()
    pdf_reader = PdfFileReader(input_pdf)
    
    for page in range(pdf_reader.getNumPages()):
        pdf_writer.addPage(pdf_reader.getPage(page))

    pdf_writer.encrypt(user_pwd=password, owner_pwd=None, use_128bit=True)
    with open(output_pdf, 'wb') as f:
        pdf_writer.write(f)

encryption('sample.pdf','encrypted.pdf','Coder101')