How to add image to PDF file in Python?

If you're here from Google, PyPDF has been replaced by PyPDF2. The syntax has changed somewhat.

import PyPDF2 as pypdf

with open("original.pdf", "rb") as inFile, open("overlay.pdf", "rb") as overlay:
    original = pypdf.PdfFileReader(inFile)
    background = original.getPage(0)
    foreground = pypdf.PdfFileReader(overlay).getPage(0)

    # merge the first two pages
    background.mergePage(foreground)

    # add all pages to a writer
    writer = pypdf.PdfFileWriter()
    for i in range(original.getNumPages()):
        page = original.getPage(i)
        writer.addPage(page)

    # write everything in the writer to a file
    with open("modified.pdf", "wb") as outFile:
        writer.write(outFile)

Look into PyPDF. You might use something like the following code to apply an overlay:

page = PdfFileReader(file("document.pdf", "rb")).getPage(0)
overlay = PdfFileReader(file("overlay.pdf", "rb")).getPage(0)
page.mergePage(overlay)

Put any overlay you want, including "Example", into overlay.pdf. Personally, I prefer PDFTK, which, while not strictly Python, can be invoked from a script with os.system(command).