This script splits each pdf page in half vertically and merge them in a single PDF in order. It asks how many pages do you want to skip to avoid splitting a book cover or a specific number of initial pages.

cutpdfpages.py

# -*- coding: utf-8 -*-
"""
This script splits each pdf page in half vertically and merge them in a single PDF in order.
It asks how many pages do you want to skip to avoid splitting a book cover or a specific number of initial pages.

Usage:
python cutpdfpages.py <filename.pdf> <newfilename.pdf>

Inspired by: https://github.com/anadeangelo/pdf_crop

"""

import sys
import copy
from PyPDF2 import PdfWriter, PdfReader

file = str(sys.argv[1])
newfile = str(sys.argv[2])

with open(file, "rb") as pdf1:
    pdf = PdfReader(pdf1)
    output = PdfWriter()
    numpages = pdf.getNumPages()
    page2skip =  int(input('Insert how many pages do you want to skip: '))

    for i in range(page2skip, numpages):
        page = pdf.pages[i]
        pagebis = copy.copy(page)
        page.mediabox.upper_left = (page.mediabox.right / 2, page.mediabox.top,)
        output.add_page(page)
        pagebis.mediabox.upper_right = (pagebis.mediabox.right / 2, pagebis.mediabox.top,)
        output.add_page(pagebis)

    with open(newfile, "wb") as newpdf:
        output.write(newpdf)

After I cut off the pdf, however this seems to just hide as the size is still the same and the cutout part can still be called out