Rotates provided pages of a file named input.pdf and saves it to output.pdf

pdf_rotate.py

import PyPDF2
import sys

rotatepages = []
inps = sys.argv[1:]

if len(inps) < 1:
    print("rotates pages of any pdf named inp.pdf, saves it to output.pdf")
    print("usage: pdf_rotate.py <spaced delimited list of pages/page ranges>\nexample: pdf_rotate.py 9-12 15 17-19\nwill rotate pages 9 10 11 12 15 17 18 and 19")
    exit(1)

for inp in inps:
    if "-" in inp:
        sinp = inp.split("-")
        [rotatepages.append(n) for n in range(int(sinp[0])-1,int(sinp[1]))]
    else:
        rotatepages.append(int(inp)-1)

if input(f"rotating these pages of inp.pdf by 90 degrees clockwise:\n{rotatepages}\nis this okay? y/N").lower() != "y":
    print("did nothing, exiting")
    exit(0)

with open('input.pdf', 'rb') as file:
    reader = PyPDF2.PdfReader(file)
    for p in rotatepages:
        page = reader.pages[p].rotate(90)
    writer = PyPDF2.PdfWriter()
    for page in reader.pages:
        writer.add_page(page)
    with open('output.pdf', 'wb') as new_file:
        writer.write(new_file)