Reading metadata

from PyPDF2 import PdfReader

reader = PdfReader("example.pdf")

meta = reader.metadata

print(len(reader.pages))

# 以下所有内容都可能为 None!
print(meta.author)
print(meta.creator)
print(meta.producer)
print(meta.subject)
print(meta.title)

Writing metadata

from PyPDF2 import PdfReader, PdfWriter

reader = PdfReader("example.pdf")
writer = PdfWriter()

# Add all pages to the writer
for page in reader.pages:
    writer.add_page(page)

# Add the metadata
writer.add_metadata(
    {
        "/Author": "Martin",
        "/Producer": "Libre Writer",
    }
)

# Save the new PDF to a file
with open("meta-pdf.pdf", "wb") as f:
    writer.write(f)