booklet printing

print_bookletstyle.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from pyPdf import PdfFileWriter, PdfFileReader
from reportlab.lib import pagesizes
from reportlab.pdfgen import canvas
from reportlab.lib.units import cm, mm, inch
from StringIO import StringIO
import sys, tempfile

PAGESIZE = pagesizes.A4

class EmptyPageReader( PdfFileReader ):
	def __init__(self,nPages=1,pagesize=None):
		buffer = StringIO()
		c = canvas.Canvas(None)
		if pagesize is None:
			pagesize = PAGESIZE
		c.setPageSize(pagesize)
		c.showOutline()
		for page in range(nPages):
			c.showPage()
		buffer.write(c.getpdfdata())
		buffer.seek(0)
		super( EmptyPageReader,self ).__init__(buffer)
	
	def __call__(s):
		return s.getPage(0)

class OffsetReader( PdfFileReader ):
	def getPage( s, n ):
		return super(OffsetReader,s).getPage( n - 1 )

def convert( input_fn, output_fn ):
	with tempfile.TemporaryFile() as tmp:
		output = PdfFileWriter()
		input = PdfFileReader(file(input_fn, "rb"))
		
		input_pagecount = input.getNumPages()
		print '%s has %d pages'%(input_fn,input_pagecount)
		
		blank = EmptyPageReader()
		
		padded_output = PdfFileWriter()
		for page in input.pages:
			padded_output.addPage( page )
		for i in range(input_pagecount % 4 ):
			padded_output.addPage(blank())
		
		padded_output.write(tmp)
		input = OffsetReader(tmp)
			
		n = input.getNumPages()
		for i in range( ( n ) / 4 ):
			print i,n
			output.addPage( input.getPage( n - ( 2 * i ) ) )
			output.addPage( input.getPage( ( 2 * i ) + 1 ) )
			output.addPage( input.getPage( ( 2 * i ) + 2 ) )
			output.addPage( input.getPage( n - ( 2 * i + 1) ) )
		
		with file(output_fn, "wb") as outputStream :
			output.write(outputStream)
	
if __name__=="__main__":
	fn = sys.argv[1]
	o = 'dummy.pdf'
	convert( fn, o )