from pathlib import Path
from pypdf import PdfWriter
book_paths = list(Path('.').glob('Book*'))
book_paths = [path for path in book_paths if path.is_dir()]
for path in book_paths:
 title = path.stem
 merger = PdfWriter()
 pdf_paths = list(path.glob('Book*.pdf'))
 flag = 1
 try:
 pdf_paths.sort(key=lambda x: int(x.stem.split('_')[3]))
 except ValueError:
 pdf_paths.sort(key=lambda x: int(x.stem.split('_')[1][2:]))
 flag = 2
 for pdf in pdf_paths:
 
 if flag == 1:
 bookmark = ' '.join(pdf.stem.split('_')[3:6])
 else:
 tmp = pdf.stem.split('_')
 ch = tmp[1][2:]
 bookmark = f"{ch} {tmp[2]}"
 # merger.append(PdfReader(pdf), outline_item=bookmark)
 merger.append(pdf, outline_item=bookmark)
 with open(f'{title}.pdf', 'wb') as f:
 merger.write(f)
 merger.close()