Combine 2 PDF pages into 1

[Cyberduke]

I'm no expert like some of the people here, but this works.

A while ago the gf worked for an Adult Education Centre. One of her jobs was to scan old exams to pdf, then watermark them with the company's logo. I made a bit of Python to do the job.

In fact, I had to learn how to do all kinds of tricks with pdfs!! Gotta keep her happy!

I made this to put the watermark picture over the text. It works fine. You can adapt it to put your picture where you want it.
Just vary the x and y values.

You can also batch this by making 2 lists of pdfs and pictures and merge them one by one.

#! /usr/bin/python3
# program to put a water mark in a pdf

import os
from reportlab.pdfgen import canvas
from PyPDF2 import PdfFileWriter, PdfFileReader

# after scanning and merging, the exams are here
pathToMergedFiles = '/home/pedro/babystuff/mergedPdf/'
# save the watermarked files here
pathToWatermarkedFiles = '/home/pedro/babystuff/watermarkedPDFs/'

# get the file names
files = os.listdir(pathToMergedFiles)

# filter out the files you don't want
pdfNames = []
for file in files:
	if file.endswith('.pdf'):
		pdfNames.append(file)


print('Where do you want the watermark on the pdf?')
print('0,0 seems to be the bottom left corner of the page.')
print('the values x = 120, y = 680 works for the first pdf')
print('For full page watermark set x = 10, y = 10 something like that')
print('enter the x value ...')
xvalue = input()
x = int(xvalue)
print('enter the y value, bottom of the page is zero')
print('enter the y value, top of the page is 720+')
print('For full page watermark set x = 10, y = 10 something like that')
print('enter the y value')
yvalue = input()
y = int(yvalue)

print('Tell me the name of the watermark file.')
print('enter something like purplerectangle.png or whiterectangle.png')
print('this should be a .png')

# get the name of the watermark picture
wmfileName = input()

# Create the watermark.pdf from an image
c = canvas.Canvas(pathToMergedFiles + 'watermark.pdf')

# Draw the image at x, y. I positioned the x,y to be where I like here
c.drawImage(pathToMergedFiles + wmfileName, x, y, mask='auto')
c.save()

# Get the watermark pdf file you just created
watermark = PdfFileReader(open(pathToMergedFiles + 'watermark.pdf', 'rb'))

# Get our files ready this is for 1 pdf file

print('What pdf file do you want to watermark?')
print('Just enter a name like test2.pdf')
pdfTowatermark = input()

outputName = pdfTowatermark.split('.')
saveFilename = outputName[0] + '_wmed.pdf'

output_file = PdfFileWriter()
input_file = PdfFileReader(open(pathToMergedFiles + pdfTowatermark, 'rb'))

# Number of pages in input document
page_count = input_file.getNumPages()

##print('Now merging the watermark and the first page ...')
### this just puts the watermark on the first page, page zero in a pdf
### Get rid of this if you want to watermark each page
##
##input_page = input_file.getPage(0)
##input_page.mergePage(watermark.getPage(0))
##output_file.addPage(input_page)

# add the rest of the pages without the rectangle
# this puts the watermark on every page

for page_number in range(0, page_count):
    #print('Now adding the other pages without the watermark ...')
    print('Watermarking page {} of {}'.format(page_number, page_count))
    # merge the watermark with the page
    input_page = input_file.getPage(page_number)
    input_page.mergePage(watermark.getPage(0))
    # add page from input file to output document
    output_file.addPage(input_page)

# finally, write "output" to document-output.pdf
with open(pathToWatermarkedFiles + saveFilename, "wb") as outputStream:
    output_file.write(outputStream)
    

# get rid of the watermark.pdf file, ready for next time if it changes
os.remove(pathToMergedFiles + 'watermark.pdf')

print('All done!')

As I have already commented, it works really well. But why does my 'watermark' get rotated by 90 degrees? it seems to happen at the insertion of the watermark.