Adds footers of the file name to a pdf via python and pypdf2

add_footer_filename.py

# Uses code borrowed from stackexchange
# https://stackoverflow.com/a/17538003

from PyPDF2 import PdfFileWriter, PdfFileReader
import io
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter

import os

fs = os.listdir()
fs = [ fi for fi in fs if fi.endswith(".pdf") ]

for f in fs:

    print("Starting " + f + ".................",end=" ")

    packet = io.BytesIO()
    can = canvas.Canvas(packet, pagesize=(720,540)) # in points, this is for slides from ppt
    can.drawString(10, 530, f) # in points, this is for slides from ppt, top left corner
    can.save()

    #move to the beginning of the StringIO buffer
    packet.seek(0)

    # create a new PDF with Reportlab
    new_pdf = PdfFileReader(packet)
    # read your existing PDF
    existing_pdf = PdfFileReader(open(f, "rb"))
    output = PdfFileWriter()
    # add the "watermark" (which is the new pdf) on the existing page
    for p in range(existing_pdf.getNumPages()):
        page = existing_pdf.getPage(p)
        page.mergePage(new_pdf.getPage(0))
        output.addPage(page)

    # finally, write "output" to a real file
    outputStream = open("ft_"+f, "wb")
    output.write(outputStream)
    outputStream.close()
    print("Finished "+f)