Merge separate scans of front and back pages to full duplex scan document.

merge_pdf_as_duplex_scan.py

# https://stackoverflow.com/questions/3444645/merge-pdf-files

import argparse
import warnings
from PyPDF2 import PdfFileWriter, PdfFileReader

parser = argparse.ArgumentParser()
parser.add_argument(dest='front', help="Scan containing front pages.")
parser.add_argument(dest='back', help="Scan containing back pages.")
parser.add_argument(dest='output', help="Output file.")
args = parser.parse_args()

def load_pdf(file_path):
    """Load and return PDF file object."""
    pdf_file = PdfFileReader(open(file_path, 'rb'), strict=False)
    return pdf_file

def sort_duplex_scan(front_pages, back_pages, output_pages):
    """Simulate duplex scan by sorting pages from two documents."""
    if(front_pages.getNumPages() != back_pages.getNumPages()):
        warnings.warn("Number of pages not matching!")
    for i in range(front_pages.getNumPages()):
        output_pages.addPage(front_pages.getPage(i))
        output_pages.addPage(back_pages.getPage(back_pages.getNumPages()-i-1))
    return output_pages

def save_pdf(output_pages, file_name):
    """Save merged PDF to given location."""
    with open(file_name, 'wb') as f:
        output_pages.write(f)

def main():
    front = load_pdf(args.front)
    back = load_pdf(args.back)
    output = PdfFileWriter()
    output = sort_duplex_scan(front, back, output)
    save_pdf(output, args.output)


if __name__ == "__main__":
    main()

merge_pdf_as_duplex_scan_gui.py

# https://stackoverflow.com/questions/3444645/merge-pdf-files

import argparse
import warnings
from PyPDF2 import PdfFileWriter, PdfFileReader
import PySimpleGUI as sg


def load_pdf(file_path):
    """Load and return PDF file object."""
    pdf_file = PdfFileReader(open(file_path, 'rb'), strict=False)
    return pdf_file

def sort_duplex_scan(front_pages, back_pages, output_pages):
    """Simulate duplex scan by sorting pages from two documents."""
    if(front_pages.getNumPages() != back_pages.getNumPages()):
        warnings.warn("Number of pages not matching!")
    for i in range(front_pages.getNumPages()):
        output_pages.addPage(front_pages.getPage(i))
        output_pages.addPage(back_pages.getPage(back_pages.getNumPages()-i-1))
    return output_pages

def save_pdf(output_pages, file_name):
    """Save merged PDF to given location."""
    with open(file_name, 'wb') as f:
        output_pages.write(f)

def main():
    layout = [[sg.T("Choose input and output location.")],
              [sg.Text("Front pages PDF: "),
               sg.FileBrowse(key="-FRONT-")],
              [sg.Text("Back pages PDF: "),
               sg.FileBrowse(key="-BACK-")],
              [sg.Text("Output pages PDF: "),
               sg.Input(key="-OUT-" , change_submits=True)],
              [sg.Button("Submit")]]
    window = sg.Window('PDF merger', layout, size=(600, 300))
    while True:
        event, values = window.read()
        if event == sg.WIN_CLOSED or event=="Exit":
            break
        elif event == "Submit":
            print()
            front = load_pdf(values["-FRONT-"])
            back = load_pdf(values["-BACK-"])
            output = PdfFileWriter()
            output = sort_duplex_scan(front, back, output)
            save_pdf(output, values["-OUT-"])


if __name__ == "__main__":
    main()