Add text to Existing PDF using Python

I need to add some extra text to an existing PDF using Python, what is the best way to go about this and what extra modules will I need to install.

Note: Ideally I would like to be able to run this on both Windows and Linux, but at a push Linux only will do.

Edit: pyPDF and ReportLab look good but neither one will allow me to edit an existing PDF, are there any other options?

Example for [Python 2.7]:

---

from pyPdf import PdfFileWriter, PdfFileReader
import StringIO
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter

packet = StringIO.StringIO()
can = canvas.Canvas(packet, pagesize=letter)
can.drawString(10, 100, "Hello world")
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(file("original.pdf", "rb"))
output = PdfFileWriter()
# add the "watermark" (which is the new pdf) on the existing page
page = existing_pdf.getPage(0)
page.mergePage(new_pdf.getPage(0))
output.addPage(page)
# finally, write "output" to a real file
outputStream = file("destination.pdf", "wb")
output.write(outputStream)
outputStream.close()

Example for Python 3.x:

---

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

packet = io.BytesIO()
can = canvas.Canvas(packet, pagesize=letter)
can.drawString(10, 100, "Hello world")
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("original.pdf", "rb"))
output = PdfFileWriter()
# add the "watermark" (which is the new pdf) on the existing page
page = existing_pdf.getPage(0)
page.mergePage(new_pdf.getPage(0))
output.addPage(page)
# finally, write "output" to a real file
outputStream = open("destination.pdf", "wb")
output.write(outputStream)
outputStream.close()

I know this is an older post, but I spent a long time trying to find a solution. I came across a decent one using only ReportLab and PyPDF so I thought I'd share:

1. read your PDF using PdfFileReader(), we'll call this input
2. create a new pdf containing your text to add using ReportLab, save this as a string object
3. read the string object using PdfFileReader(), we'll call this text
4. create a new PDF object using PdfFileWriter(), we'll call this output
5. iterate through input and apply .mergePage(*text*.getPage(0)) for each page you want the text added to, then use output.addPage() to add the modified pages to a new document

This works well for simple text additions. See PyPDF's sample for watermarking a document.

Here is some code to answer the question below:

packet = StringIO.StringIO()
can = canvas.Canvas(packet, pagesize=letter)
<do something with canvas>
can.save()
packet.seek(0)
input = PdfFileReader(packet)

From here you can merge the pages of the input file with another document.

pdfrw will let you read in pages from an existing PDF and draw them to a reportlab canvas (similar to drawing an image). There are examples for this in the pdfrw examples/rl1 subdirectory on github. Disclaimer: I am the pdfrw author.

cpdf will do the job from the command-line. It isn't python, though (afaik):

cpdf -add-text "Line of text" input.pdf -o output .pdf

Leveraging David Dehghan's [answer][2] above, the following works in Python 2.7.13:

from PyPDF2 import PdfFileWriter, PdfFileReader, PdfFileMerger

import StringIO

from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter

packet = StringIO.StringIO()
# create a new PDF with Reportlab
can = canvas.Canvas(packet, pagesize=letter)
can.drawString(290, 720, "Hello world")
can.save()

#move to the beginning of the StringIO buffer
packet.seek(0)
new_pdf = PdfFileReader(packet)
# read your existing PDF
existing_pdf = PdfFileReader("original.pdf")
output = PdfFileWriter()
# add the "watermark" (which is the new pdf) on the existing page
page = existing_pdf.getPage(0)
page.mergePage(new_pdf.getPage(0))
output.addPage(page)
# finally, write "output" to a real file
outputStream = open("destination.pdf", "wb")
output.write(outputStream)
outputStream.close()

[2]: https://stackoverflow.com/a/17538003/1432614 "answer"

Don't use mergePage, It may not work for some pdfs You should use mergeRotatedTranslatedPage

from PyPDF2 import PdfFileWriter, PdfFileReader
import io
from reportlab.pdfgen.canvas import Canvas

page_to_merge = 0 #Refers to the First page of PDF 
xcoor = 250 #To be changed according to your pdf
ycoor = 650 #To be changed according to your pdf

input_pdf = PdfFileReader(open("Source.pdf", "rb"))
page_count = input_pdf.getNumPages()
inputpdf_page_to_be_merged = input_pdf.getPage(page_to_merge)

packet = io.BytesIO()
c = Canvas(packet,pagesize=(inputpdf_page_to_be_merged.mediaBox.getWidth(),inputpdf_page_to_be_merged.mediaBox.getHeight()))
c.drawString(xcoor,ycoor,"Hello World")
c.save()
packet.seek(0)

overlay_pdf = PdfFileReader(packet)
overlay = overlay_pdf.getPage(0)

output = PdfFileWriter()

for PAGE in range(page_count):
    if PAGE == page_to_merge:
        inputpdf_page_to_be_merged.mergeRotatedTranslatedPage(overlay, 
                inputpdf_page_to_be_merged.get('/Rotate') or 0, 
                overlay.mediaBox.getWidth()/2, overlay.mediaBox.getWidth()/2)
        output.addPage(inputpdf_page_to_be_merged)
    
    else:
        Page_in_pdf = input_pdf.getPage(PAGE)
        output.addPage(Page_in_pdf)

outputStream = open("destination.pdf", "wb")
output.write(outputStream)
outputStream.close()

If you're on Windows, this might work:

PDF Creator Pilot

There's also a whitepaper of a PDF creation and editing framework in Python. It's a little dated, but maybe can give you some useful info:

Using Python as PDF Editing and Processing Framework

You may have better luck breaking the problem down into converting PDF into an editable format, writing your changes, then converting it back into PDF. I don't know of a library that lets you directly edit PDF but there are plenty of converters between DOC and PDF for example.