merge PDF files

import os
from PyPDF2 import PdfFileMerger

x = [a for a in os.listdir() if a.endswith(".pdf")]
x.sort()

merger = PdfFileMerger()

for pdf in x:
    merger.append(open(pdf, 'rb'))

name = x[-1]
from pathlib import Path

name = Path(name).resolve().stem

with open(name + '까지.pdf', "wb") as fout:
    merger.write(fout)