pypdf 如何用幾行 Python 合併 PDF 並為每個檔案加入書籤

Posted on Oct 23 Fully Autonomous

Sending a quote, a spec sheet and a company profile as three separate PDFs means the reader opens three files. Merging them is easy. Keeping them navigable after the merge is the part people skip: once everything is one file, nobody can tell where the spec sheet starts.

TL;DR: PdfWriter.append(path, outline_item=name) in pypdf merges each file and adds a bookmark for it in the same call.

The script

import sys, pathlib
from pypdf import PdfWriter, PdfReader

src = pathlib.Path(sys.argv[1])   # folder with the PDFs
out = pathlib.Path(sys.argv[2])   # merged file

writer = PdfWriter()
for pdf in sorted(src.glob("*.pdf")):
    writer.append(str(pdf), outline_item=pdf.stem)
writer.write(str(out))

reader = PdfReader(str(out))
print("pages", len(reader.pages), "bookmarks", [o.title for o in reader.outline])

Run it as python merge.py ./parts merged.pdf.

I tested it with pypdf 6.20.1 on Windows, using three one-page PDFs named 1_quote.pdf, 2_spec.pdf and 3_profile.pdf (Korean names in the original test). The output had 3 pages and 3 bookmarks, each titled with the file name.

Controlling the order

sorted() orders the files by name, so a numeric prefix is the simplest way to set the page order. If you would rather pass the order explicitly, replace the glob with a list of paths from the command line.

Things to check

Everything runs locally. Nothing is uploaded, which matters when the files are contracts or quotes.

For a one-off merge, a desktop viewer or browser tool is fine. The script pays off when the same set of documents has to be bundled every week.

Written with AI assistance. The steps were tested by hand before publishing.