Convert a book with glued pages into singular pages using PyPDF2 and MuPDF

book-convert.py

# This script process PDF documents with inconsistent structure like this:
#
# [ PAGE 1 ] - 595x840
# [ PAGE 2 ] - 595x840
# [ PAGE 3 | PAGE 4 ] - 1191x840
# [ PAGE 5 ] - 595x840
# [ PAGE 6 | PAGE 7 ] - 1191x840
# [ PAGE 8 ] - 595x840
#
# I haven't find an easy way to trim and split single page using Python so used MuPDF instead
#
# Install MuPDF using preferable package manager:
# apt install mupdf
# brew install mupdf

from PyPDF2 import PdfFileReader, PdfFileWriter
import subprocess
import sys
import os

inputpdf = PdfFileReader(open("input.pdf", "rb"))
outputpdf = PdfFileWriter()

for i in range(inputpdf.numPages):
    page = inputpdf.getPage(i)
    print(page.mediaBox)
    pageSizeX = page.mediaBox[2]

    if pageSizeX > 600:
        with open("tmp.pdf", "wb") as outputStream:
            output = PdfFileWriter()
            output.addPage(inputpdf.getPage(i))
            output.write(outputStream)
    	
        # mutool poster -x 2 -y 1 input.pdf output.pdf
        result = subprocess.run(
            ["mutool", "poster", "-x", '2', '-y', '1', 'tmp.pdf', 'output.pdf'], capture_output=True, text=True
        )
        tmp = PdfFileReader(open("output.pdf", "rb"))
        for n in range(tmp.numPages):
            outputpdf.addPage(tmp.getPage(n))

        os.remove("tmp.pdf")
        os.remove("output.pdf")
    else:
        outputpdf.addPage(inputpdf.getPage(i))

with open("result.pdf", "wb") as outputStream:
    outputpdf.write(outputStream)